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Fecal microbiota transplantation (FMT) is a therapeutic modality for treating neonatal calf diarrhea. Several practical barriers, including donor selection, fecal collection, and a limited timeframe for FMT, are the main constraints to using fresh feces for implementing on-farm FMT. We report the utility of FMT with pretreated ready-to-use frozen (F) or freeze-dried (FD) microorganisms for treating calf diarrhea. In total, 19 FMT (F-FMT, n = 10 and FD-FMT, n = 9) treatments were conducted. Both FMT treatments were 100% clinically effective; however, multi-omics analysis showed that FD-FMT was superior to F-FMT. Machine learning analysis with SourceTracker confirmed that donor microbiota was retained four times better in the recipient calves treated with FD-FMT than F-FMT. A predictive model based on receiver operating characteristic curve analysis and area under the curve showed that FD-FMT was more discriminative than F-FMT of the observed changes in microbiota and metabolites during disease recovery. These results provide new insights into establishing methods for preparing fecal microorganisms to increase the quality of FMT in animals and may contribute to FMT in humans., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethics declarations The study was conducted in accordance with the Guidelines for Laboratory Animal Welfare and Animal Experiment Control promulgated by the ethics committee of Chiba NOSAI Kanji-kai (Approval No. CNS190901 and CNS190902). It is confirmed that the authors complied with the ARRIVE guidelines., (© 2024. The Author(s).)

Parenteral antimicrobial treatment results in the excretion of antimicrobial-resistant bacteria. Dairy cows are commonly housed side by side in tie-stalls and often receive antimicrobial treatment. However, studies investigating treated cows as source of colonization of neighboring cows with resistant bacteria are scarce. Antimicrobial resistance (AMR) in cows (treated and untreated) in tie-stalls was investigated to assess their respective risks of carrying resistant bacteria. Furthermore, we analyzed associations of farm management with AMR. Case-control study: For isolation of indicator Escherichia (E.) coli, rectal swab samples were taken. Cows were sampled depending on treatment history and proximity to one another (cow A: recently treated parenterally; cow B: untreated, next to cow A; cow C: untreated, at considerable distance from all treated cows). Antimicrobial susceptibility was tested by microdilution. Associations of AMR with exposure to cow A, treatments, and management were analyzed using generalized mixed-effects logistic models. Susceptibility data on 571 isolates from 131 dairy farms were obtained. Almost no difference in proportions of resistant E. coli was observed between cows B and C (B: 53.4%; C: 57.2%; P = 0.52). Untreated cows had lower odds of carrying resistant E. coli than treated cows (B: OR 0.44, P<0.001; C: OR 0.54, P = 0.007). Non-pansusceptibility of isolates was associated with antimicrobial treatment (1 treatment: OR 2.11, P = 0.001; ≥2: OR 1.76, P = 0.043). Using manure on forage crops was associated with higher odds of pansusceptibility (OR 2.01, P = 0.004). For daily practice, with regard to the risk of AMR transmission, results of this study do not provide evidence for the need to separate treated cows from others during treatment in tie-stalls., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Köchle et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Bovine respiratory disease (BRD) is common in intensively raised cattle and is often treated with antibiotics. For practitioners, knowledge of the bacteria involved in an outbreak and their antibiotic susceptibility is warranted. To this end, samples from the upper or lower respiratory tract of calves can be submitted for bacteriological culture and susceptibility testing of relevant isolates. However, it is debated whether isolates from the upper respiratory tract are representative of bacteria causing infections in the lower respiratory tract. In this study, we used MALDI-TOF MS, multilocus sequence typing (MLST) and core-genome multilocus sequence typing (cgMLST) to compare culture results of 219 paired samples (sample pairs) of deep nasal swabs (DNS) and tracheobronchial lavage (TBL). The sample pairs came from 171 calves in 30 calf groups across 25 farms with 48 calves sampled twice., Results: The predominant bacterial pathogen was Pasteurella multocida, which was isolated from 37.4% of DNS and 22.4% of TBL. There was no statistically significant difference in isolation frequency of P. multocida between calves considered healthy and those suspected for BRD for DNS (P = 0.778) or TBL (P = 0.410). Among the 49 sample pairs where P. multocida was isolated from TBL, the same species was isolated from DNS in 29 sample pairs (59.2%). Isolates from 28 of these sample pairs were evaluated by MLST, and in 24 pairs (86.0%) P. multocida from DNS and TBL were of the same sequence type (ST). Moreover, cgMLST showed that the genetic distance between isolates within 21 of the 28 sample pairs (75.0%), was less than two alleles, and DNS and TBL isolates were considered identical. In seven sample pairs (25%), the genetic distance was greater, and DNS and TBL isolates were considered nonidentical., Conclusions: Pasteurella multocida was readily isolated from DNS and in calves where this species was isolated also from TBL, DNS and TBL isolates were identical in 75% of the sample pairs. This suggests that during an outbreak of BRD, submission of DNS samples from 4 to 6 calves could be a convenient approach for practitioners seeking guidance on P. multocida present in the lower respiratory tract and their antibiotic susceptibility., (© 2024. The Author(s).)

Shiga toxin - producing Escherichia coli (STEC) are major foodborne pathogens that result in thousands of hospitalizations each year in the United States. Cattle, the natural reservoir, harbor STEC asymptomatically at the recto-anal junction (RAJ). The molecular mechanisms that allow STEC and non-STEC E. coli to adhere to the RAJ are not fully understood, in part because most adherence studies utilize human cell culture models. To identify a set of bovine-specific E. coli adherence factors, we used the primary RAJ squamous epithelial (RSE) cell-adherence assay to coculture RSE cells from healthy Holstein cattle with diverse E. coli strains from bovine and nonbovine sources. We hypothesized that a comparative genomic analysis of the strains would reveal factors associated with RSE adherence. After performing adherence assays with historical strains from the E. coli Reference Center ( n = 62) and strains newly isolated from the RAJ ( n = 15), we used the bioinformatic tool Roary to create a pangenome of this collection. We classified strains as either low or high adherence and using the Scoary program compiled a list of accessory genes correlated with the "high adherence" strains. While none of the correlations were statistically significant, several gene clusters were associated with the high-adherence phenotype, including two that encode uncharacterized proteins. We also demonstrated that non-STEC E. coli strains from the RAJ are more adherent than other isolates and can outcompete STEC in coculture with RSEs. Further analysis of adherence-associated gene clusters may lead to an improved understanding of the molecular mechanisms of RSE adherence and may help develop probiotics targeting STEC in cattle., Importance: E. coli strains that produce Shiga toxin cause foodborne illness in humans but colonize cattle asymptomatically. The molecular mechanisms that E. coli uses to adhere to cattle cells are largely unknown. Various strategies are used to control E. coli in livestock and limit the risk of outbreaks. These include vaccinating animals against common E. coli strains and supplementing their feed with probiotics to reduce the carriage of pathogens. No strategy is completely effective, and probiotics often fail to colonize the animals. We sought to clarify the genes required for E. coli adherence in cattle by quantifying the attachment to bovine cells in a diverse set of bacteria. We also isolated nonpathogenic E. coli from healthy cows and showed that a representative isolate could outcompete pathogenic strains in cocultures. We propose that the focused study of these strains and their adherence factors will better inform the design of probiotics and vaccines for livestock., Competing Interests: The authors declare no conflict of interest.

Klebsiella pneumoniae, common pathogenic bacteria, cause dangerous infectious diseases in animals and humans. Klebsiella pneumoniae have numerous resistance mechanisms to antibacterials and the frequency of resistant K. pneumoniae isolates increases, making treatment of K. pneumoniae-induced infections difficult. Farm animals are a possible source of antibacterial resistant K. pneumoniae. The aim of this literature review (2018-2024) was to evaluate the antibacterial resistance of K. pneumoniae isolated from poultry, cattle and pigs in various countries. The analysis shows that farm animals are an important source of antibacterial-resistant and multidrug-resistant K. pneumoniae and that resistance patterns differ among antibacterial groups, animals and locations. In poultry, high resistance to penicillins (91%), III and IV generation cephalosporins (> 50%) occurred, and low to carbapenems (5%) and polymyxins (6%). In cattle, high resistance to sulphonamides (76%), IV generation cephalosporins, macrolides and lincosamides, and penicillins occurred (> 50%), and low to carbapenems (10%) and polymyxins (1%). Isolates from pigs showed high resistance to I and II-generation cephalosporins, I-generation fluoroquinolones, macrolides and lincosamides, tetracyclines (> 50%) and carbapenems (> 20%), and low to polymyxins (5%). The highest resistance rates to most antibacterial groups occurred in pigs, and in Africa and Asia, while the lowest in cattle, and in North and South America. Particularly, the relatively high resistance of K. pneumoniae to carbapenems and polymyxins in Africa poses a threat to animal and human health as these antibiotics are the last resort therapeutics used to treat severe infections. Different rates of K. pneumoniae resistance to antibacterials among isolates from farm animals probably result from differences in the treatment of each animal group with various antibacterial agents and different regimes of their use in various locations., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Although Amblyomma variegatum and Ehrlichia ruminantium infections have been reported in cattle from some agro-ecological zones (AEZs) of Cameroon, the transmission patterns of this bacterium seem to vary according to endemic areas and its prevalence as well as that of Heartwater remains not well understood in most sub-Saharan African countries. This study was designed to detect E. ruminantium infections in cattle of four AEZs of Cameroon and to identify areas presenting enzootic stability and those with potentially high risk for Heartwater. Blood samples were collected from cattle in four AEZs of Cameroon. DNA was extracted from blood and semi-nested PCR targeting the 16S rRNA gene of E. ruminantium was used to search for this bacterium. From 569 cattle analysed, an E. ruminantium DNA fragment was detected in 197 of them, giving an overall prevalence of 34.6%. The highest prevalence of E. ruminantium of 48.0% was recorded in cattle from AEZ IV and the lowest (26.0%) in those from AEZ III. Among the AEZs, significant differences (X 2 = 14.85, p = 0.002) were recorded in terms of the prevalence of E. ruminantium infections. Villages of the westerly areas are at higher risk for E. ruminantium infections. This study revealed a high prevalence and a wide distribution of E. ruminantium infections in AEZs of Cameroon. It enabled the identification of areas showing an enzootic stability for E. ruminantium transmission as well as those where the transmission of this bacterium is low and where livestock are at higher risk of developing Heartwater., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Background: Rickettsial infections are often neglected and poorly recognized by physicians in many tropical and subtropical regions. Despite a number of recent reports describing rickettsial diseases in new locations and the discovery of new rickettsiae, medical science and research have largely neglected the diagnosis and antimicrobial treatment of rickettsial infections in subtropical and tropical areas; thus, much remains to be discovered. This study aimed to detect and characterize spotted fever group (SFG) rickettsiae in ixodid ticks infesting domestic ruminants in Khartoum State., Methods: Polymerase chain reaction targeting both genes that encode for citrate synthase (gltA) and outer membrane protein (ompA) was performed for the presence of SFG rickettsia followed by sequence and phylogenetic analysis., Results: Of the 202 ticks examined for the presence of SFG rickettsia, gltA gene was detected in 4 samples (2%). Furthermore, gltA-positive samples were used to amplify the ompA gene, in which only two samples yielded positive results. Sequence and phylogenetic analysis of the positive samples revealed four different species of SFG rickettsiae: Rickettsia aeschlimannii, Rickettsia rhipicephali, Rickettsia massiliae and Rickettsia raoultii., Conclusions: These results indicated the presence of SFG rickettsia in Sudanese ticks. This also indicates that humans have an opportunity to acquire these infections. It is important to keep in mind the need for careful consideration of rickettsial infections in individuals with a fever of unknown origin., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Copper (Cu) ions have been recognized for their efficacy in inactivating bacteria, including Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne's disease (JD) known for its resilience to unfavorable conditions. However, the response of MAP isolates isolated from cows to Cu exposure remains inadequately understood, as their responses may differ from those of laboratory-adapted reference strains. In this study, we examined the response of MAP isolates obtained from MAP-infected and affected cows to Cu ion treatment, comparing that with the response of the reference strain ATCC 19698 to the same treatment. Three MAP field isolates and the MAP reference strain were exposed to Cu ions, and their viability, protein/lipid damage, ROS production, and gene expression were evaluated in triplicate. Survival differed among isolates, with an isolate from a cow with clinical JD exhibiting increased tolerance to Cu exposure. While Cu treatment induced lipid peroxidation and ROS production across all isolates, genes associated with Cu detoxification and virulence were upregulated, particularly in the reference strain. Whole genome sequencing analysis revealed that, despite genomic similarities between field isolates and the reference strain ATCC 19698, there were differences regarding the presence/absence of genes related with certain virulence factors. Further research on Cu exposure with larger numbers of MAP isolates is needed to explain the stress-induced responses that influence MAP survival during natural infections and in challenging environments., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Bovine Genital Campylobacteriosis (BGC) is caused by Campylobacter fetus subsp. venerealis and is a notifiable disease to the WOAH (World Organisation for Animal Health). For an effective BGC control program, the reliable differentiation of Campylobacter fetus subsp. venerealis (Cfv) from the closely related Campylobacter fetus subsp. fetus (Cff) is required. However, the available molecular C. fetus subspecies identification assays lack sensitivity and specificity to differentiate C. fetus isolates based on their phenotypic or genotypic differences. Furthermore, the current biochemical subspecies identification is not fully congruent with the genomic differentiation of C. fetus strains. In this study, the genome sequences of 41C. fetus strains with well identified subspecies, were analyzed with the large-scale BLAST score ratio (LS-BSR) pipeline to identify Cff and Cfv specific sequences. With this analysis, the asd gene encoding an aspartate-semialdehyde dehydrogenase was identified, which contained a 6-bp Cff-specific sequence, and this 6-bp sequence was absent in the asd gene of Cfv strains. This sequence was used for the development of PCR assays to differentiate Cff and Cfv strains. The C. fetus subspecies identification of the developed asd PCR assays was in full congruence with the genomic classification of strains and are recommended for molecular identification of C. fetus subspecies in BGC control programs. The asd PCR can be assessed on sequenced genomes using a web interface containing the Cfvcatch tool, which includes placement of the tested genome in a phylogenetic tree with reference C. fetus genomes to distinguish the two subspecies and to detect antimicrobial resistance genes., Competing Interests: Declaration of competing interest The author(s) declare that there are no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background/objective: Abortions in livestock herds are a major contributor to economic losses. The incidence of fungal aetiology has been reported thus far. The purpose of this study is to investigate the prevalence of abortions due to fungi in referred cases to the Center of Excellence in Ruminant Abortion and Neonatal Mortality, Veterinary Hospital of Ferdowsi University of Mashhad, Mashhad, Iran, from different provinces of Iran., Methods: A total of 200 calves were referred between 2018 and 2022. Samples were taken from the lungs, liver, spleen and abomasum. The fungi present in the cultures were analysed microscopically and morphologically., Results: There were varying contamination levels in the liver, spleen and lungs, with prevalence ranging from 15% to 17%. Abdomasum had a 1% prevalence rate. Different fungal species, including Cryptococcus neoformans (C. neoformans), Aspergillus spp., Rhodotorula spp., Trichosporon spp., Candida spp., Geotrichum spp., Penicillium spp. and Mucor spp., were identified, indicating a diverse range of pathogens affecting calves. The specificity of fungal contaminants in certain organs, such as C. neoformans, Rhodotorula spp. and Trichosporon spp., highlighted the organ's microenvironment as a potential factor influencing fungal growth., Conclusion: As fungi are emerging as a significant cause of morbidity and mortality in animals, the growing role of fungi in livestock abortions should be investigated. As clinical signs are not pathognomonic, laboratory help is imperative to confirm fungal abortion diagnosis., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

We investigated antimicrobial resistance-related genes in 109 isolates of Trueperella pyogenes that were isolated in cattle and pigs. All 89 tetracycline-resistant T. pyogenes isolates carried the resistance gene harbored either tetW, tetM, tetA(33), tetK, or tetL. The ermX or ermB were detected in 18 of 23 erythromycin-resistant isolates. Streptomycin-resistant aadA1, aadA9, aadA11, aadA24, strA, or strB were detected in 25 of 83 isolates. There were significant differences in the percentages of tetA(33), ermB, aadA1, aadA9, aadA11, or aadA24 carriage between cattle and pig isolates. In addition, the Class 1 gene cassette was detected only in 17 cattle isolates. This suggests that T. pyogenes isolates acquire resistance gene in each environment of cattle and pigs, and that the transmission of the bacteria between cattle and pigs is limited.

Mycoplasma bovis infections are wide spread in veal calf farms and a major contributor to respiratory disease. M. bovis are genetically diverse. It is unclear how this diversity influences the virulence and epidemiology of infections on veal calf farms over time. Therefore, the aim of this study was to follow the genetic composition of M. bovis isolates on veal farms over time in a fattening round and combine this with presence of disease and presence of other respiratory pathogens. For this, M. bovis isolates were obtained from healthy and diseased calves from ten different farms at different episodes of respiratory disease in the same groups in one fattening round. A new episode of respiratory disease was defined by the practitioner based on clinical diagnosis at least 7 days after end of a previous metaphylactic treatment. These isolates were sequenced using Illumina sequencing and analysed. This resulted in 148 sequenced isolates. The isolates belonged to 9 different clusters and to the known MLST sequence types ST4 (n=9), ST6 (n=2), ST7 (n=1), ST8 (n=1), ST21 (n=32), ST29 (n=30), ST32 (n=1), ST100 (n=36), ST122 (n=17) and ST135 (n=4), and new sequence types ST222 (n=8), ST223 (n=1), ST224 (n=5) and ST225 (n=1). Major sequence types are linked to types, found in other European countries. All farms showed presence of two or more different clusters, however with different distribution patterns. Farms did not show a major shift in type distribution over time. There was a relationship between M. bovis type and region of origin of the calves and the types differed with regards of presence of variable membrane surface lipoprotein (Vsp) genes. Types were not related to disease status of the calves or presence of other major respiratory pathogens. This study underlines the complexity of M. bovis infection on veal calf farms with persistent presence of different types together in both healthy and diseased calves with or without other respiratory pathogens. Prevention of introduction of M. bovis and biosecurity measures combined with optimisation of calf resilience should have priority., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Erik van Engelen reports financial support was provided by The consortium is financed by the Dutch Ministry of Economic Affairs, the former Product Board for Livestock, Meat and Eggs, MSD Animal Health, the VanDrie Group, and Denkavit. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Pathogenic bacteria Leptospira spp. are commonly associated with bovine leptospirosis, characterized chiefly by chronic and subclinical reproductive disorders. Strains from the Sejroe serogroup play a significant role in these chronic genital infections known as Bovine Genital Leptospirosis (BGL), which notably impact cattle health. This study aims to deepen our understanding of BGL by investigating the genetic diversity, geographical distribution, and specific anatomical sites of infection of the causative agents. Initially, uterine fragments and cervicovaginal mucus were collected from 47 cows and subjected to PCR targeting the lipL32 gene. Positive samples in lipL32-PCR (9 samples) underwent genotyping based on the secY gene. Subsequently, sequences were aligned with GenBank entries (108 sequences) and analyzed in silico. All nine sequences from this study were identified as L. interrogans with an identity >99 % to serogroup Sejroe reference strains (Norma and L53). In the broader analysis, the most prevalent species observed was L. borgpetersenii, followed by L. interrogans and L. santarosai. The haplotype network of L. interrogans revealed that haplogroups B and C exclusively included L. interrogans strains of genital origin, while haplogroup A encompassed strains from renal sources as well. These findings underscore the significance of the L. borgpetersenii genotype Hardjobovis and L. interrogans genotype Hardjoprajitno as the predominant circulating strains and highlight the existence of distinct haplogroups of pathogenic leptospires originating from genital sources. We advocate for the use of secY as an effective genetic marker for Leptospira spp. and stress the necessity for additional research prioritizing the genital tract. The outcomes of this study contribute to the development of improved control measures for chronic cattle diseases and provide valuable guidance for future investigations., Competing Interests: Declaration of Competing Interest None of the authors has any other financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Salmonella spp. infections in animals are a concern due to their zoonotic nature, welfare effects and economic impact on the livestock industry. To enable targeted surveillance, it is important to identify risk factors for the introduction of Salmonella spp. in a herd. Since 2009, Dutch dairy processors require herds delivering milk to their plants to participate in a Salmonella programme. In this programme, bulk milk is tested three times a year (i.e. test rounds) by ELISA on presence of antibodies against Salmonella spp. serogroups B and D. Based on these bulk milk results we identified newly infected herds, and aimed to identify associated risk factors. Effects of putative risk factors for becoming newly infected were studied using a multivariable population average logistic regression (PA-GEE) model with binomial distribution. Per test round in 2019-2021, 0.85-4.10 % of the Dutch dairy herds at risk became newly infected, with large regional differences. Several risk factors for becoming newly infected in the context of the low herd-level prevalence were identified. The most evident risk factors that were identified were having at least one infected or recently recovered dairy herd within 500 m (OR = 2.67), on-farm presence of pigs (OR = 1.63), introduction of more than 2 cattle from other herds in the previous 12 months (OR = 1.17), being in an area with a relative soil moisture of >0.54 % (OR = 1.31), being located in an area with a high water surface area (>2 %; OR = 1.14) and a larger herd size (OR = 1.65). These results indicate that, in addition to introduction of cattle, local transmission plays an important role in the between-herd transmission of Salmonella spp. Information on risk factors for becoming newly infected based on regularly collected data, can be used to improve surveillance and to implement targeted control measures against salmonellosis., Competing Interests: Declaration of Competing Interest None, (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Slaughterhouse inspections play a crucial role in the sanitary control of zoonoses and foodborne diseases. This study aimed to identify and analyze the frequencies of lymph node diseases in cattle slaughtered for human consumption, using the samples sent to the anatomic pathology service of the Federal Laboratory for Agricultural Defense ( Laboratório Federal de Defesa Agropecuária ), Minas Gerais, Brazil, from January 2015 to September 2022. In total, 2000 lymph node samples were analyzed, and additional information was individually retrieved. Lesions were most frequently identified in thoracic lymph nodes. Bacterial isolation and quantitative polymerase chain reaction (qPCR) were performed using samples suspected of tuberculosis. Tuberculosis cases accounted for 89.3% of the samples. Histopathology was more sensitive than other ancillary tests for diagnosing tuberculosis. Paraffin-embedded tissues from lymphoma cases were subjected to immunophenotyping using anti-CD3 and anti-CD79a immunohistochemistry. Frozen and/or paraffin-embedded tissues from lymphoma cases were used to identify the enzootic bovine leukosis (EBL) retrovirus through qPCR. Other diagnoses included primary (T- and B-cell lymphoma) and metastatic neoplasms (squamous cell carcinoma, pulmonary adenocarcinoma, undifferentiated carcinoma, undifferentiated adenocarcinoma, undifferentiated sarcoma, undifferentiated round cell tumor, mesothelioma, hepatic carcinoid, meningioma, and seminoma), actinogranulomas (pyogranulomatous lymphadenitis [actinobacillosis and actinomycosis]), idiopathic lymphadenitis (neutrophilic and/or histiocytic, granulomatous, and suppurative), and miscellaneous nonspecific lymphadenopathies (depletion/lymphoid atrophy, lymphangiectasia, erythrocyte drainage, parasitic eosinophilic lymphadenitis, follicular hyperplasia, and toxic granulomatous lymphadenitis). The combination of histopathology with complementary techniques is important for successful diagnosis, especially in complex cases of high epidemiological, economic, and zoosanitary importance, such as tuberculosis and EBL., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Hemoplasma infections in cattle are caused by Mycoplasma wenyonii and Candidatus Mycoplasma haemobos and induce asymptomatic or chronic infections but occasionally lead to life-threatening hemolytic anemia. Despite the global distribution of bovine hemoplasmas, information regarding their transmission vectors and prevalence is still lacking in the Republic of Korea. Therefore, this study aims to investigate the infection rate of bovine hemoplasma in cattle and houseflies and to assess the risk factors associated with hemoplasma infection in cattle., Methods: Overall, 376 blood samples were collected from Korean indigenous cattle (male, 10-13 months old), along with 2,690 houseflies (Musca domestica) from the same farm where the cattle were raised. PCR assays targeting the 16S rRNA gene were performed to detect hemoplasmas, and positive samples were sequenced., Results: The infection rate of bovine hemoplasmas was 50.8% (191/376) in cattle and 7.4% in pooled houseflies. Among cattle, 18.6% (70/376) and 20.0% (75/376) tested positive for M. wenyonii and Candidatus M. haemobos, respectively. Conversely, in houseflies, Candidatus M. haemobos was more frequently detected (5.9%) than M. wenyonii (0.7%). Co-infection was 12.2% (46/376) in cattle and 0.7% in flies. Furthermore, hemoplasma infection was significantly associated with the grazing experience of their dams. Cattle born to cows with grazing experience exhibited a higher risk for M. wenyonii infection (odds ratio [OR] = 1.62; 95% confidence interval [CI]: 1.03-2.55; P = 0.045), whereas these cattle had a lower risk for Candidatus M. haemobos infection (OR = 0.32, 95% CI: 0.19-0.74; P = 0.000) than animals born to cows without grazing experience. The sequences obtained from houseflies were confirmed as Candidatus M. haemobos, which displayed high similarity (98.2-100%) to those from cattle obtained in this study., Conclusions: To our knowledge, this study represents the first report of bovine hemoplasmas identified in houseflies. This molecular evidence suggests that houseflies may be possible vectors for Candidatus M. haemobos., (© 2024. The Author(s).)

Adult house flies (Musca domestica L.) are important reservoirs and mechanical vectors of bacteria in livestock operations. House fly bacterial communities are influenced by their local environment, yet a comprehensive understanding of bacterial diversity, pathogen prevalence, and bacterial source is not fully understood. We characterized bacterial communities from adult female house flies and associated manure samples from beef and dairy cattle farms in Kansas, Oklahoma, and Texas over four months (July-October). Bacterial community composition in flies and manure reflected the local environment, and house flies shared the majority (≥ 99%) of bacterial taxa with manure. The variability of bacterial diversity was greater among individual fly (species richness range: 48-1747) samples than manure (species richness range: 345-1162). Temporal variability of fly bacterial diversity was observed within each farm type. Bacterial taxa of veterinary and medical importance such as Corynebacterium, Turicibacter, Staphylococcus, Streptococcus, and Acinetobacter were highly prevalent in flies, constituting core bacterial communities. The prevalence of bacterial taxa associated with bovine keratoconjunctivitis (IBK) and bovine respiratory disease (BRD) was higher in flies than in manure and prevalence varied monthly. This study underscores the crucial role house flies play as carriers of cattle pathogens, contributing to their dissemination among animals and to off-site locations, where they pose a threat to surrounding communities and agricultural operations., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Background: Mycoplasma bovis is a global pathogen of cattle but was detected for the first time in New Zealand in 2017, triggering a response under their Biosecurity Act as an "unwanted organism". Following a lengthy eradication campaign, the Ministry of Primary Industries (MPI) now requires all bovine semen destined for export to New Zealand to be screened with an M. bovis-specific real-time PCR (rtPCR) compliant with amended import health standard (IHS) test requirements aimed at preventing the accidental importation of M. bovis. The standard stipulates that semen samples cannot be centrifuged prior to DNA extraction. To comply with these strict requirements, one of the listed tests was validated together with different DNA preparation steps and compared with existing in-house procedures. DNA was extracted from semen straws using the current in-house semi-automated platform procedures for processing culture, tissue and body fluid sample submissions and was compared with the stipulated test requirements. DNA from centrifuged and unspun semen samples spiked with M. bovis was also compared., Results: The rtPCR had a sensitivity and specificity of 100% (95% confidence interval = 79-100% and 74-100%, respectively) when testing DNA from other Mycoplasma species or bovine semen spiked with the latter, with a high level of repeatability for within- and between- run replicates. The consistent limit of detection was 0.001 pg/µl M. bovis DNA and between 5.3 × 10 2 and 7.5 × 10 2 CFU/ml M. bovis when artificially spiked in semen. DNA extracted using the KingFisher Flex was detected with lower Cq values than the Maxwell 16, but the comparable improvements in sensitivity were mainly associated with non-centrifuged samples (p < 0.001). None of the procedures tested impeded the detection sensitivity of M. bovis in the presence of competitor organisms Acholeplasma laidlawii, Mycoplasma bovigenitalium and Ureaplasma diversum, confirming M. bovis specificity of the polC target., Conclusions: Under the experimental conditions applied, this rtPCR test efficiently detected M. bovis in extended bovine semen straw samples from DNA extracted using both semi-automated extraction platforms, irrespective of prior centrifugation of extended semen., (© 2024. Crown.)

Background: Ticks represent a significant vector for the transmission of infectious diseases, with the prevalence of tick-borne diseases becoming a prominent global health concern in recent decades. Anaplasma spp., Rickettsia spp., and Piroplasma have been identified as significant pathogens with the potential to impact human and animal health. However, there is a dearth of data concerning the prevalence of these pathogens in the eastern Tibetan Plateau, China., Methods: In this study, a total of 643 Dermacentor silvarum and 314 Haemaphysalis longicornis were identified through the application of morphological and molecular identification techniques on 957 ticks collected from yaks in Zoige County. The assessed of Anaplasma spp., Rickettsia spp., Theileria spp., and Babesia spp. was assessed in 957 ticks and 96 blood samples collected from yaks., Results: Significant discrepancies were observed in the positivity rates for the four pathogens among the tick species and sampling sites. The identification of different species within the four pathogens was based on the analysis of the 16S rRNA of Anaplasma spp., the ompA and ompB genes of Rickettsia spp., and the 18S rRNA of Theileria spp. and Babesia spp. The prevalence ranges of the four pathogens are 9.9-50.2%, 29.5-100%, 16.2-46.4%, and 14.5-58.4%, respectively., Conclusion: In view of the growing zoonotic risks, further investigations into the prevalence of additional pathogens in ticks and animals, including livestock, in the eastern Tibetan Plateau, China, are essential., Competing Interests: The authors declare that the research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xiang, He, Zhu, Xiao, Pan, Chen, Zheng, Yuan and Hao.)

This longitudinal study characterized Salmonella circulating in lymph nodes (LN, n = 800) and beef trimmings (n = 745) from slaughter cattle from a Mexican feedlot. During two years, LN and beef trimming samples were collected 72-96 h post-slaughter, and we obtained 77 isolates of the serovars Anatum (n = 23), Reading (n = 22), Typhimurium (n = 10), London (n = 9), Kentucky (n = 6), Fresno (n = 4), Give, Muenster, and monophasic 1,4,[5],12:i- (n = 1 each). These isolates were subjected to whole genome sequencing, single-nucleotide polymorphism (SNP)-based phylogenetic analysis, reconstruction of their ancestral isolation sources through evolutionary analysis, and virulence profiling. Although LN and beef trimmings were not mixed, evolutionary analysis estimated that the common ancestor of all study isolates was likely of LN origin. Moreover, isolates from both sources were highly clonal (0-21 SNP distance), highlighting the complexity of Salmonella transmission dynamics. The pathogen persisted across cattle cohorts, as shown by clonality between isolates collected in different years (1-20 SNP distance). Major virulence genes were highly conserved (97-100% identity to the reference sequences) and most isolates carried a conserved version of pathogenicity islands 1-5, 9, 11, and 12. Typhimurium strains carried the Salmonella plasmid virulence operon (spvRABCD), and a Muenster isolate carried the st313td gene, both of which are associated with invasive phenotypes. Most isolates (49/77) were genetically similar (1-43 SNPs) to strains involved in human salmonellosis, highlighting their public health significance. Further research is needed on Salmonella transmission dynamics in cattle and the mechanisms determining subclinical infection and persistence in farm environments., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Delgado-Suárez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Leptospirosis is an emerging zoonotic disease with high health and economic damage. In this study, we developed a deterministic mathematical model that describes the dynamics of leptospirosis transmission within a cattle herd, incorporating asymptomatic infected and vaccinated compartments. The study examined the transmission role of asymptomatic cattle that contaminate herds without farmers' knowledge. We proved the well-posedness of the proposed model and found the basic reproduction number using the next-generation matrix. Analytically, we demonstrated that the disease-free equilibrium point is locally and globally asymptotically stable when R 0 is less than unity and is otherwise unstable. Graphically, we further established the local asymptotic stability of disease-free and endemic equilibria. Sensitivity analysis showed that the contact rate with asymptomatic infected cattle, β A , is the most sensitive parameter in the stated model, followed by the recovery rate of asymptomatic infected cattle, σ , and the vaccination rate of susceptible cattle, τ . Numerical simulations revealed that a reduction in contact rate with asymptomatic infected cattle significantly reduced pathogen Leptospira transmission in the herd. In addition, fostering the recovery rate of asymptomatic infected cattle can significantly reduce new infections in the herd. Furthermore, augmenting the vaccination rate among susceptible cattle resulted in a notable decrease in disease prevalence within the herd. Findings of this study underscore the remarkable importance of targeted interventions, such as reducing contact rates with asymptomatic infected cattle, increasing recovery rates using proper treatments, and enhancing vaccination efforts to manage leptospirosis transmission in cattle herds., (© 2024. The Author(s).)

Babesiosis and Anaplasmosis are diseases associated with economic losses; ticks and blood-sucking flies are important zoonotic vectors and reservoirs. This study aimed to investigate the presence of anti-Babesia spp. and anti-Anaplasma marginale antibodies using enzyme-linked immunosorbent assay (ELISA), in ruminants at the Catimbau National Park. Blood samples were collected from 119 sheep, 119 goats, and 47 cattle. Rhipicephalus microplus ticks were collected from cattle. ELISA showed seropositivity of 34% (16/47), 20.3% (24/119), and 16% (19/119) for anti-Babesia bovis; 34% (16/47), 15.2% (18/119), and 9% (7/119) for anti-Babesia bigemina; and 34% (16/47), 35.6% (42/119), and 17% (20/119) for anti-A. marginale antibodies in cattle, goats, and sheep, respectively. The information collected using an epidemiological questionnaire showed that mostly are breed in a semi-intensive system, with access to Caatinga vegetation. The circulation of B. bovis, B. bigemina, and A. marginale was confirmed. Thus, based on the prevalence, this suggests this is an enzootic instability area and is prone to outbreaks.

Escherichia coli O157:H7-adulterated food products are associated with disease outbreaks in humans. Although cattle feces are a source for E. coli O157:H7 contamination, it is unclear if human-associated outbreak isolates differentially colonize and shed in the feces of cattle from that of non-outbreak isolates. It is also unclear if phenotypes, such as biofilm formation, cell attachment, or toxin production, differentiate environmental E. coli O157:H7 isolates from those associated with human illness. The objective of this study was to compare the genotypes and phenotypes of a diverse set of E. coli O157:H7 isolates, with the intent of identifying differences that could inform cattle colonization and fecal shedding, along with virulence potential in humans. Isolates differed in attachment phenotypes on human Caco-2 cells and bovine-derived recto-anal junction squamous epithelial cells, with curli having a strong impact on attachment to the human-derived cell line. The prototypical E. coli O157 isolate EDL933 had the greatest expression of the adhesin gene iha , yet it had decreased expression of the virulence genes stx2 , eae , and ehxA compared the lineage I/II isolates RM6067W and/or FRIK1989. Strong or weak biofilm production was not associated with significant differences in cattle colonization or shedding, suggesting biofilms may not play a major role in cattle colonization. No significant differences in cattle colonization and fecal shedding were detected, despite genomic and in vitro phenotypic differences. The outbreak isolate associated with the greatest incidence of hemolytic uremic syndrome, RM6067W, induced the greatest Vero cell cytotoxicity and had the greatest stx2 gene expression., Importance: Foodborne illness has major impacts on global health and imposes financial hardships on food industries. Escherichia coli serotype O157:H7 is associated with foodborne illness. Cattle feces are a source of E. coli O157:H7, and routine surveillance has led to an abundance of E. coli O157:H7 genomic data. The relationship between E. coli O157:H7 genome and phenotype is not clearly discerned for cattle colonization/shedding and improved understanding could lead to additional strategies to limit E. coli O157:H7 in the food chain. The goal of the research was to evaluate genomic and phenotypic attributes of E. coli O157:H7 associated with cattle colonization and shedding, environmental persistence, and human illness. Our results indicate variations in biofilm formation and in vitro cellular adherence was not associated with differences in cattle colonization or shedding. Overall, processes involved in cattle colonization and various phenotypes in relation to genotype are complex and remain not well understood., Competing Interests: The authors declare no conflict of interest.

Klebsiella species commonly reside in dairy cattle guts and are consistently exposed to beta-lactam antibiotics, including ceftiofur, which are frequently used on the U.S. dairy farms. This may impose selection pressure and result in the emergence of extended-spectrum beta-lactamase (ESBL)-producing strains. However, information on the status and antimicrobial resistance (AMR) profile of ESBL- Klebsiella spp. in the U.S. dairy farms is largely unknown. This study aimed to determine the prevalence and AMR profile of ESBL- Klebsiella spp. and the factors affecting their occurrence in dairy cattle farms. Rectal fecal samples ( n = 508) and manure, feed, and water samples ( n = 64) were collected from 14 dairy farms in Tennessee. Samples were directly plated on CHROMagar ESBL, and presumptive Klebsiella spp. were confirmed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Antimicrobial susceptibility testing was performed on the isolates against panels of 14 antimicrobial agents from 10 classes using minimum inhibitory concentration. Of 572 samples, 57 (10%) were positive for ESBL- Klebsiella spp. The fecal prevalence of ESBL- Klebsiella spp. was 7.2% (95% CI: 6.5-8.0). The herd-level fecal prevalence of ESBL- Klebsiella spp. was 35.7% (95% CI: 12.7-64.8). The fecal prevalence of ESBL- Klebsiella spp. was significantly higher in calves than in cows and higher in cows with higher parity (≥3) as compared to cows with low parity ( P < 0.001). Most (96.5%, n = 57) ESBL- Klebsiella spp. were resistant to ceftriaxone. The highest level of acquired co-resistance to ceftriaxone in ESBL- Klebsiella spp. was to sulfisoxazole (66.7%; 38/57). About 19% of ESBL-K lebsiella spp. were multidrug resistant. The presence of ESBL-producing Klebsiella spp. in dairy cattle, feed, and water obtained from troughs could play a crucial epidemiological role in maintaining and spreading the bacteria on farms and serving as a point source of transmission., Importance: We collected 572 samples from dairy farms, including rectal feces, manure, feed, and water. We isolated and identified extended-spectrum beta-lactamase (ESBL)- Klebsiella spp. and conducted an antimicrobial susceptibility test and analyzed different variables that may be associated with ESBL- Klebsiella spp. in dairy farms. The results of our study shed light on how ESBL- Klebsiella spp. are maintained through fecal-oral routes in dairy farms and possibly exit from the farm into the environment. We determine the prevalence of ESBL- Klebsiella spp. and their antimicrobial susceptibility profiles, underscoring their potential as a vehicle for multiple resistance gene dissemination within dairy farm settings. We also collected data on variables affecting their occurrence and spread in dairy farms. These findings have significant implications in determining sources of community-acquired ESBL- Enterobacteriaceae infections and designing appropriate control measures to prevent their spread from food animal production systems to humans, animals, and environments., Competing Interests: The authors declare no conflict of interest.

Salmonella enterica serotype Cerro ( S . Cerro) is an emerging Salmonella serotype isolated from cattle, but the association of S . Cerro with disease is not well understood. While comparative genomic analyses of bovine S . Cerro isolates have indicated mutations in elements associated with virulence, the correlation of S . Cerro fecal shedding with clinical disease in cattle varies between epidemiologic studies. The primary objective of this study was to characterize the infection-relevant phenotypes of S . Cerro fecal isolates obtained from neonatal calves born on a dairy farm in Wisconsin, USA. The S . Cerro isolates varied in biofilm production and sensitivity to the bile salt deoxycholate. All S . Cerro isolates were sensitive to sodium hypochlorite, hydrogen peroxide, and acidic shock. However, S . Cerro isolates were resistant to nitric oxide stress. Two S . Cerro isolates were unable to compete with S . Typhimurium during infection of calf ligated intestinal loops, indicating decreased fitness in vivo . Together, our data suggest that S . Cerro is sensitive to some innate antimicrobial defenses present in the gut, many of which are also used to control Salmonella in the environment. The observed phenotypic variation in S . Cerro isolates from a single farm suggest phenotypic plasticity that could impact infectious potential, transmission, and persistence on a farm.IMPORTANCE Salmonella enterica is a zoonotic pathogen that threatens both human and animal health. Salmonella enterica serotype Cerro is being isolated from cattle at increasing frequency over the past two decades; however, its association with clinical disease is unclear. The goal of this study was to characterize infection-relevant phenotypes of S . Cerro isolates obtained from dairy calves from a single farm. Our work shows that there can be variation among temporally related S . Cerro isolates and that these isolates are sensitive to killing by toxic compounds of the innate immune system and those used for environmental control of Salmonella . This work contributes to our understanding of the pathogenic potential of the emerging pathogen S . Cerro., Competing Interests: The authors declare no conflict of interest.

Shiga toxin-producing Escherichia coli (STEC) are zoonotic pathogens frequently carried by cattle, responsible in humans of mild to bloody diarrhoea, haemolytic uraemic syndrome (HUS) and even death. In 2023-2024, a study on STEC contamination of hide and carcasses of dairy cattle at slaughter was planned in Emilia-Romagna region (northern Italy). When the study was still in progress and 60 animals were sampled, the detection of STEC O177 isolates reached high rates and gained our attention. A total of five O177 STEC strains were detected, namely four from three carcasses (5.0 %) and one from a hide sample (1.7 %). The isolates were typed by WGS as following: 1) STEC O177:H11 sequence type (ST) 765 (stx2a + , eae + ), detected from one carcass; 2) STEC O177:H25 ST659 (stx2c + , eae + ) detected from three carcasses and one hide sample. One carcass was contaminated by both STEC serotypes. The isolates carried other virulence determinants often found in STEC strains associated with HUS, namely the exha, astA and espP genes, together with genes for adhesion to the epithelial cells of the gut (lpfA, fdeC, fimH) and non-Locus for Enterocyte Effacement (LEE) effector protein genes (nleA, nleB). The STEC O177:H11 isolate harboured antimicrobial resistance (AMR) genes to β-lactams (bla TEM-1 A ), aminoglycosides (aadA1, aph(3″)-Ib, aph(6)-Id), trimethoprim (dfrA1), sulphonamides (sul1, sul2), tetracyclines (tetA), (tetB), streptothricin (sat2), and quaternary ammonium compounds (qacEdelta1). On the contrary, the STEC O177:H25 isolates carried no AMR genes. Persistent carriage of STEC O177:H25 ST659 (stx2c + , eae + ) at farm level was assessed by testing animals of the same herd sent to slaughter. Interestingly, the colonies of STEC O177:H11 and STEC O177:H25 had different morphology on CHROMagar™ STEC plates, being mauve and colourless, respectively. Since mauve is the colour STEC colonies commonly have on the CHROMagar™ STEC medium, our findings can help microbiologists in the selection of uncommon serotypes. To the best of our knowledge, this is the first detection of STEC O177 from carcasses and hides of dairy cattle at slaughter. Noteworthy, the STEC-positive hide was classified as "very dirty" thus stressing the need of clean animals entering the slaughter chain, as required by Regulation (EC) No 853/2004. Since STEC O177 has been responsible of HUS in Europe, our data could add information on the source of uncommon serogroups in human infections., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the study reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

To investigate the epidemiology of Shiga toxin-producing Escherichia coli (STEC) in dairy cattle, 975 samples (185 feces, 34 silage, 36 cattle drinking water, 360 raw milk, and 360 teat skin swabs) were collected from two dairy farms in Baoji and Yangling, Shaanxi Province, China, and were screened for STEC. Whole-genome sequencing was used to analyze the genomic characteristics and potential transmission of STEC isolates. A total of 32 samples were contaminated with STEC, including 4.0% (19/479) in Farm A and 2.6% (13/496) in Farm B. Compared with adult cows (4.5%), nonadult cows had a higher rate (21.3%) of STEC colonization. A total of 14 serotypes and 11 multilocus sequence typing were identified in 32 STEC isolates, among which O55:H12 (25.0%) and ST101 (31.3%) were the most predominant, respectively. Six stx subtypes/combinations were identified, including stx1a (53.1%), stx2g (15.6%), stx2d , stx2a + stx2d , stx1a + stx2a (6.3%, for each), and stx2a (3.1%). Of 32 STEC isolates, 159 virulence genes and 27 antibiotic resistance genes were detected. Overall, STEC isolates showed low levels of resistance to the 16 antibiotics tested (0-40.6%), with most common resistance to ampicillin (40.6%). The phylogenetic analysis confirmed that STEC in the gut of cattle can be transmitted through feces. The results of this study help to improve our understanding of the epidemiological aspects of STEC in dairy cattle and provide early warning and control of the prevalence and spread of the bacterium.

The overuse of antimicrobials in livestock has contributed to the emergence and selection of clinically relevant multidrug-resistant bacteria. In Brazil, there is no conclusive information on the occurrence of Escherichia coli producing extended-spectrum β-lactamase (ESβL) in cattle breeding, which is an important sector of agribusiness in this country. Herein, we investigated the presence of ESβL-positive E. coli strains in dairy cattle from a commercial farm with routine practice of therapeutic cephalosporins. Ninety-five rectal swab samples were collected from healthy dairy calves and cows under treatment with ceftiofur. Samples were screened for the presence of ESβL producers, and positive isolates were identified by MALDI-TOF, with subsequent screening for genes encoding ESβL variants by PCR and sequencing. The presence of ESβL (CTX-M-15)-producing E. coli was confirmed in calves, and lactating and dry cows. Most ESβL strains with genetic homologies ≥ 90% were grouped into two major PFGE clusters, confirming the suscessful expansion of clonally related lineages in animals from different lactating cycles, on the same property. Four representatives CTX-M-15-positive E. coli strains had their genomes sequenced, belonging to the clonal complex (CC) 23 and sequence type (ST) 90. A phylogeographical landscape of ST90 was performed revealing a global One Health linkage. Our results highlight the intestinal microbiota of dairy cattle as a hotspot for the spread of critical priority ESβL-producing E. coli and demonstrate that ST90 is an international clone genomically adapted to human and animal hosts, which deserve additional investigation to determine its zoonotic potential and impact in food chain., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Many cattle infected with Mycoplasma bovis remain healthy while others develop severe chronic respiratory disease. We hypothesized that inflammatory stimuli such as co-pathogens worsen disease outcomes in M. bovis-infected calves. Calves (n=24) were intrabronchially inoculated with M. bovis and either killed bacterial lysate, transient M. haemolytica infection, or saline. Caseonecrotic lesions developed in 7/7 animals given M. haemolytica and M. bovis compared to 2/8 given M. bovis with no inflammatory stimulus, and 6/9 animals given bacterial lysate and M. bovis (P=0.01). Animals receiving M. haemolytica and M. bovis had more caseonecrotic foci in lungs than those receiving M. bovis with no inflammatory stimulus (median = 21 vs 0; P = 0.01), with an intermediate response (median = 5) in animals given bacterial lysate. In addition to caseonecrotic foci, infected animals developed neutrophilic bronchiolitis that appeared to develop into caseonecrotic foci, peribronchiolar lymphocytic cuffs that were not associated with the other lesions, and 4 animals with bronchiolitis obliterans. The data showed that transient lung inflammation at the time of M. bovis infection provoked the development of caseonecrotic bronchopneumonia, and the severity of inflammation influenced the number of caseonecrotic foci that developed. In contrast, caseonecrotic lesions were few or absent in M. bovis-infected calves without a concurrent inflammatory stimulus. These studies provide insight into how caseonecrotic lesions develop within the lung of M. bovis-infected calves. This and other studies suggest that controlling co-pathogens and harmful inflammatory responses in animals infected with M. bovis could potentially minimize development of M. bovis caseonecrotic bronchopneumonia., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Johne's disease (JD), caused by Mycobacterium avium subspecies paratuberculosis (MAP), poses significant challenges to the global livestock industry, particularly affecting bovine populations. To better understand the prevalence of paratuberculosis and its diagnostic nuances, a comprehensive meta-analysis was conducted. This analysis encompassed 21 studies involving 632,767 cows for milk enzyme-linked immunosorbent assay (ELISA) and 51 studies involving 256,409 cows for serum ELISA. The pooled prevalence estimate for paratuberculosis on a cow-basis was found to be 16% (95% CI: 14%; 18%) for milk ELISA and 8% (95% CI: 7%; 8%) for serum ELISA. Notably, higher confidence intervals (CI) were observed in milk ELISA, the Europe and Asia groups, suggesting variability in prevalence estimates within these regions. Conversely, lower CIs were noted in the USA and Canada groups, indicating greater consistency in prevalence estimates within these countries. However, serum ELISA exhibited high CI values across all regions, underscoring potential variability in diagnostic performance. These findings provide valuable insights for veterinarians, researchers, policymakers, and livestock producers in optimizing paratuberculosis detection and control strategies to mitigate its impact on bovine health and agricultural productivity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In cattle, bovine respiratory syncytial virus (BRSV) is associated with secondary bacterial infections; however, the mechanisms of the interaction between BRSV and bacteria are unclear. Trueperella pyogenes (T. pyogenes) causes pneumonia in cattle and is involved in secondary infections following viral infections. In this study, we evaluated the effect of BRSV infection on the adhesion of T. pyogenes to BRSV-infected cells. BRSV infection significantly enhanced the adhesion of T. pyogenes to cells in a multiplicity of infection- and time-dependent manner. The BRSV-mediated change in the adhesion of T. pyogenes was widely observed in various cell types and bacterial strains. The results from the gentamicin protection assay showed that BRSV infection did not affect the intracellular invasion ability of T. pyogenes. Furthermore, adhesion assays conducted using BRSV G protein-expressing cells and anti-BRSV G antibodies revealed that the increased adhesion of T. pyogenes to cells was mediated by the G protein of BRSV. In addition, immunofluorescence assay revealed the colocalization of BRSV G protein and T. pyogenes. Thus, BRSV infection can potentially lead to bovine respiratory disease complex by promoting the adhesion of T. pyogenes to the infected cells.

Objective: Flagellin protein, an integral component of flagella, provides motility to several bacterial species and also acts as a candidate antigen in diagnostics and subunit vaccines. The bulk production of flagellin with retention of all conformational epitopes using recombinant protein technology is of paramount importance in the development of pathogen-specific immuno-assays and vaccines. We describe the production of highly soluble and immuno-reactive rFliA(C) protein of Clostridium chauvoei, a causative agent of blackleg or black quarter (BQ) affecting cattle and small ruminants worldwide. The bacterium is known to possess peritrichous flagella that provide motility and also act as a virulence factor with high protective antigenicity., Methods: Upon sequence and structural analysis, a partial fliA(C) gene from Clostridium chauvoei was cloned and the recombinant mature protein with N- and C- terminal truncation was over-expressed as a His-tagged fusion protein (∼25 kDa) in Escherichia coli. Subsequently, rFliA(C) protein was purified by single-step affinity chromatography and characterized for its immuno-reactivity in laboratory animals, Western blot, and indirect-ELISA format., Results: rFliA(C) was highly soluble and was purified in high quantity and quality. rFliA(C) elicited antigen-specific conformational polyclonal antibodies in rabbit and guinea pig models, as well as anti-Clostridium chauvoei-specific antibodies being specifically detected in BQ-vaccinated and convalescent sera of bovines in Western blot and in indirect-ELISA format. Further, no cross reactivity was noted with antibodies against major bovine diseases (e.g., foot-and-mouth disease, IBR, LSDV, hemorrhagic septicaemia, brucellosis, and leptospirosis)., Conclusion: The study indicated the production of conformational recombinant flagellin-rFliA(C)-antigen and its potential utility in development of diagnostics for detection of Clostridium chauvoei-specific antibodies in BQ-recovered and/or vaccinated animals., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Melioidosis, an emerging infectious disease that affects both humans and animals, is caused by the soil-dwelling bacterium Burkholderia pseudomallei. It is endemic in South and Southeast Asia, and northern Australia, causing an estimated 165,000 human cases annually worldwide. Human cases have been reported in the French West Indies (Martinique and Guadeloupe) since the 1990s. Conversely, no human cases have been reported in French Guiana, a French territory in South America. Our study aimed to investigate whether B. pseudomallei is locally established in Guadeloupe and French Guiana using animals as a proxy., Methodology/principal Findings: Blood samples were collected from different animals from 56 farms in French Guiana (n = 670) and from two goat farms in Les Saintes (n = 31), part of the Guadeloupe archipelago and tested by enzyme-linked immunosorbent assay (ELISA). In Les Saintes, a serological follow-up was performed, and soil, water and goat rectal swabs were collected and analyzed by culture and PCR. The highest seroprevalence rates (39%) were observed in goats in Les Saintes, followed by horses (24%) and cattle (16%) in French Guiana. In the two goat farms, supplementary analyses detected B. pseudomallei from one goat rectal swab, and a B. pseudomallei strain was isolated from the soil., Conclusions/significance: Our animal serological data suggest the presence of B. pseudomallei in Les Saintes and French Guiana. In Les Saintes, environmental surveys confirmed the endemicity of the bacteria, which is consistent with documented human cases of melioidosis on the island. We did not conduct an environmental survey in French Guiana. Nevertheless, our serological results call for local environmental surveys and a retrospective reassessment of human infections with melioidosis-like symptoms., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Gasqué et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The bovine leukocyte antigen (BoLA) gene is a significant genetic part of the immune system and has been used as a disease marker in cattle. In this study, we detected Theileria orientalis, T. sinensis, Anaplasma marginale, Anaplasma platys, Candidatus Mycoplasma haemobos and Trypanosoma evansi by PCR amplification and sequencing of the amplicons. The allelic association of the BoLA-DRB3.2 gene with blood pathogen disease resistance and susceptibility in 87 Kedah-Kelantan x Brahman (KKB) and 38 Bali cattle was determined by Fisher's exact test and Cochran Mantel Haenszel (CMH) correction test. Sequence-based typing of the BoLA-DRB3.2 gene identified 43 alleles (27 previously reported alleles and 16 novel alleles) across the two cattle breeds. Alignment analysis of the 16 novel alleles revealed 90.7-95.8% and 85-92% nucleotide and amino acid identities, with the reference allele, BoLA-DRB3*016:01 cDNA clone NR-1. BoLA-DRB3*009:02 (25.6%) and BoLA-DRB3*036:01 (36%) were the most frequent alleles in KKB and Bali cattle, respectively. In KKB cattle, BoLA-DRB3*020:02:01 was significantly associated with resistance to T. orientalis whereas *007:01 and *009:02 were significantly associated with resistance to C. Mycoplasma haemobos. Also, DRB3*017:01 was associated with susceptibility to T. orientalis in KKB cattle. In the Bali cattle, BoLA-DRB3*015:01 was found to be a genetic marker of susceptibility to C. Mycoplasma haemobos infection. Therefore, this study identified BoLA-DRB3.2 alleles associated with resistance and susceptibility to T. orientalis infection in KKB cattle and susceptibility to C. Mycoplasma haemobos infection in Bali cattle for the first time. Therefore, this study suggests that these BoLA-DRB3 resistance alleles could be used as candidate markers for selection, whereas susceptibility alleles could be used as candidate markers for culling in the beef industry., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Vector-borne pathogens continue to increase their impact on the livestock industry worldwide. To protect animals against these pathogens, it is very important to identify the species that cause the disease and understand their prevalence. This study aimed to investigate the presence and prevalence of vector-borne pathogens in apparently healthy cattle in different parts of Kyrgyzstan using molecular diagnostic techniques. For this purpose, 531 blood samples were collected from the Osh, Jalal-Abad, and Batken oblasts of Kyrgyzstan. The blood samples were investigated for vector-borne pathogens using PCR, RLB, and RFLP. Moreover, DNA sequence analyses were used to confirm the results of molecular techniques and phylogenetic analyses of these pathogens. 359 (67.61%) out of 531 samples were found to be infected with at least one pathogen, whereas 172 (32.39%) were detected to be negative. Thirteen vector-borne pathogens were detected in cattle blood samples, and the prevalence of these pathogens was as follows: Theileria orientalis (47.83%), T. annulata (25.61%), Babesia major (0.19%), B. occultans (0.38%), Anaplasma phagocytophilum-like 1 (3.20%), A. capra (3.01%), A. centrale (2.82%), A. bovis (1.13%), (A) ovis (0.19%), Candidatus Anaplasma camelii (0.94%), Trypanosoma theileri (19.21%), Mycoplasma wenyonii (6.03%), and Ca. Mycoplasma haemobos (2.64%). Among the positive samples, one pathogen was identified in 189 cattle (35.59%), and co-infections (two or more pathogens) were determined in 170 (32.01%) animals. Theileria parva, T. mutans, (B) bigemina, B. bovis, B. divergens, and A. marginale could not be detected in the study. Anaplasma bovis and Ca. Anaplasma camelii were detected for the first time in the country. This molecular survey provides important epidemiological and genetic data for the vector-borne pathogens in cattle. The results of the study showed that vector-borne pathogens have a significant spread and distribution in cattle in Kyrgyzstan., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: The objective of this study was to explore the relative frequency and seasonality of bovine respiratory pathogens in the UK, based on clinical case submission for laboratory PCR testing., Methods: This study used retrospective data generated by a central Scotland laboratory using 407 clinical (pooled) samples collected by 95 veterinary practices located throughout the UK between November 2020 and September 2022. Statistical analyses were performed using descriptive spatial analysis (choropleth maps), chi-squared analysis, Poisson and logistic regression modelling., Results: The majority (77.6%) of the samples had more than one species of bacteria identified, and 17.7% had multiple viruses identified. In comparison with the colder months of autumn and winter (September to February), the warmer months (March to August) were significantly associated with lower odds of respiratory disease caused by certain pathogens. Poisson models showed small but significant univariable associations between total viruses (coefficient = ‒0.01, standard error [SE] = 0.004, 95% confidence interval [CI] = ‒0.02 to ‒0.003) and total pathogens (coefficient = ‒0.005, SE = 0.002, 95% CI = ‒0.008 to 0.002) and increasing weekly age., Limitations: This is an inherently biased population because it only comprises clinical samples submitted to a single UK laboratory, and the data were analysed retrospectively., Conclusions: A large majority of clinical bovine respiratory disease (BRD) samples were multipathogenic, and pathogens such as bovine coronavirus (which has generally not been considered a significant contributing pathogen in the BRD complex in the UK) were prevalent., (© 2024 The Author(s). Veterinary Record published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

A plethora of infectious and non-infectious causes of bovine abortions and perinatal mortalities (APM) have been reported in literature. However, due to financial limitations or a potential zoonotic impact, many laboratories only offer a standard analytical panel, limited to a preestablished number of pathogens. To improve the cost-efficiency of laboratory diagnostics, it could be beneficial to design a targeted analytical approach for APM cases, based on maternal and environmental characteristics associated with the prevalence of specific abortifacient pathogens. The objective of this retrospective observational study was to implement a machine learning pipeline (MLP) to predict maternal and environmental factors associated with infectious APM. Our MLP based on a greedy ensemble approach incorporated a standard tuning grid of four models, applied on a dataset of 1590 APM cases with a positive diagnosis that was achieved by analyzing an extensive set of abortifacient pathogens. Production type (dairy/beef), gestation length, and season were successfully predicted by the greedy ensemble, with a modest prediction capacity which ranged between 63 and 73 %. Besides the predictive accuracy of individual variables, our MLP hierarchically identified predictor importance causes of associated environmental/maternal characteristics of APM. For instance, in APM cases that happened in beef cows, season at APM (spring/summer) was the most important predictor with a relative importance of 24 %. Furthermore, at the last trimester of gestation Trueperella pyogenes and Neospora caninum were the most important predictors of APM with a relative importance of 22 and 17 %, respectively. Interestingly, herd size came out as the most relevant predictor for APM in multiparous dams, with a relative importance of 12 %. Based on these and other mix of predicted environmental/maternal and pathogenic potential causes, it could be concluded that implementing our MLP may be beneficial to design a more cost-effective, case-specific diagnostic approach for bovine APM cases at the diagnostic laboratory level., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Anaplasma spp. and Rickettsia spp. are intracellular vector-borne pathogens and harbored by a wide range of ticks and vertebrate hosts. Aim of this study was to molecularly characterize Anaplasma spp. and Rickettsia spp. in different ticks collected from livestock hosts in nine districts of Khyber Pakhtunkhwa (KP), Pakistan. In total, 862 ticks were collected from cattle, goats and sheep. Highest tick's infestation was observed on cattle 56.14% (32/57), followed by goats 45.45% (40/88), and sheep 42.05% (45/107). Rhipicephalus microplus (305/862, 35.38%) was predominant species, followed by Haemaphysalis sulcata (243/862, 28.19%), Hyalomma anatolicum (133/862, 15.42%), Haemaphysalis bispinosa (120/862, 13.92%), and Hyalomma kumari (61/862, 7.07%). A subset of 135 ticks were screened for Anaplasma spp. and Rickettsia spp. based on the amplification of partial 16 S rDNA and outer-membrane protein A (ompA) fragments, respectively. In total, 16 ticks (11.85%) were positive for Anaplasma spp. and Rickettsia spp. Obtained 16 S rDNA sequences for Anaplasma spp. detected in Ha. bispinosa and Ha. sulcata showed 99.98% identity with Anaplasma bovis, while other detected in Rh. microplus showed 99.84% identity with Candidatus Anaplasma boleense. Similarly, detected ompA sequence in Ha. sulcata showed 100% identity with Rickettsia sp. and 97.93% with Rickettsia slovaca, and another sequence detected in Rh. microplus showed 100% identity with Candidatus Rickettsia shennongii. In phylogenetic trees, these sequences clustered with corresponding species from Pakistan, China, Turkey, South Korea, South Africa, and Herzegovina. This is the first study reporting detection of A. bovis in Ha. bispinosa and Ha. sulcata, Ca. A. boleense in Rh. microplus collected from goats, and R. slovaca-like in Ha. sulcata. Our results enforce the need for regular surveillance of Rickettsiales in hard ticks infesting livestock in the region., (© 2024. The Author(s).)

The use of antimicrobial drugs in food-producing animals contributes to the selection pressure on pathogenic and commensal bacteria to become resistant. This study aims to evaluate the existence of trade-offs between treatment effectiveness, cost, and the dynamics of resistance in gut commensal bacteria. We developed a within-host ordinary differential equation model to track the dynamics of antimicrobial drug concentrations and bacterial populations in the site of infection (lung) and the gut. The model was parameterized to represent enrofloxacin treatment for bovine respiratory disease (BRD) caused by Pastereulla multocida in cattle. Three approved enrofloxacin dosing regimens were compared for their effects on resistance on P. multocida and commensal E. coli: 12.5 mg/kg and 7.5 mg/kg as a single dose, and 5 mg/kg as three doses. Additionally, we explored non-FDA-approved regimes. Our results indicated that both 12.5 mg/kg and 7.5 mg/kg as a single dose scenario increased the most the treatment costs and prevalence of P. multocida resistance in the lungs, while 5 mg/kg as three doses increased resistance in commensal E. coli bacteria in the gut the most out of the approved scenarios. A proposed non-FDA-approved scenario (7.5 mg/kg, two doses 24 h apart) showed low economic costs, minimal P. multocida, and moderate effects on resistant E. coli. Overall, the scenarios that decrease P. multocida, including resistant P. multocida did not coincide with those that decrease resistant E. coli the most, suggesting a trade-off between both outcomes. The sensitivity analysis suggests that bacterial populations were the most sensitive to drug conversion factors into plasma ( β ), elimination of the drug from the colon ( ϑ ), fifty percent sensitive bacteria (P. multocida) killing effect ( L s50 ), fifty percent of bacteria (E. coli) above ECOFF killing effect ( C r50 ), and net drug transfer rate in the lung ( γ ) parameters., (© 2024. The Author(s).)

Background: Calf diarrhea is a major cause of morbidity and mortality in the livestock sector worldwide and it can be caused by multiple infectious agents. In Ethiopia, cattle are the most economically important species within the livestock sector, but at the same time the young animals suffer from high rates of morbidity and mortality due to calf diarrhea. However, studies including both screening and molecular characterization of bovine enteric pathogens are lacking. Therefore, we aimed to both detect and molecularly characterize four of the major enteric pathogens in calf diarrhea, Enterotoxigenic Escherichia coli (E. coli K99 +), Cryptosporidium spp., rotavirus A (RVA), and bovine coronavirus (BCoV) in calves from central Ethiopia. Diarrheic and non-diarrheic calves were included in the study and fecal samples were analyzed with antigen-ELISA and quantitative real-time PCR (qPCR). Positive samples were further characterized by genotyping PCRs., Results: All four pathogens were detected in both diarrheic and non-diarrheic calves using qPCR and further characterization showed the presence of three Cryptosporidium species, C. andersoni, C. bovis and C. ryanae. Furthermore, genotyping of RVA-positive samples found a common bovine genotype G10P[11], as well as a more unusual G-type, G24. To our knowledge this is the first detection of the G24 RVA genotype in Ethiopia as well as in Africa. Lastly, investigation of the spike gene revealed two distinct BCoV strains, one classical BCoV strain and one bovine-like CoV strain., Conclusions: Our results show that Cryptosporidium spp., E. coli K99 + , RVA and BCoV circulate in calves from central Ethiopia. Furthermore, our findings of the rare RVA G-type G24 and a bovine-like CoV demonstrates the importance of genetic characterization., (© 2024. The Author(s).)

Background: Staphylococcus aureus has emerged as a major public health concern. It is a common pathogen in animal and human medicine., Aim: Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) was used to fingerprint 10 strains of S. aureus obtained from nasal swabs in domesticated animals and humans to ascertain how comparable the different strains' genetic makeup was., Methods: These isolates were previously identified using standard molecular and microbiological methods. ERIC primers were amplified for all isolates. The dendrogram was generated using PGMA and the dice similarity coefficient. The strains were genotyped according to the diversity of sample source (human or animal), and the geographic source., Results: Ten S. aureus strains were classified into eight "ERIC" kinds (genotypes) using "ERIC-PCR genotyping", in which the two most common clones were genotypes 8 and 2, which were represented by one strain from humans, one from cows, and two strains from sheep. Two strains derived from separate geographic areas and from different sample sources (human and cow) were determined to share the same genotype. Another two strains from different geographic areas but from the same sample source (sheep) were categorized under the same genotype. All the remaining strains were classified as a singular genotype., Conclusion: This study supports the possible bacterial transmission from animal to human and from animals themselves that usually happens during live animal marketing. Recognizing the interconnected nature of transmission systems and implementing the required approaches to disease prevention and control is essential for mitigating the risks posed by bacterial pathogens., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this research.

Background: Colibacillosis caused by Escherichia coli causes significant economic losses in the livestock sector worldwide and is one of the calves' leading causes of diarrhea., Aim: This study aimed to identify the most frequent E. coli molecularly pathotypes in calves with diarrhea in six provinces of the Cajamarca region in the northern highlands of Peru., Methods: Twenty-eight herds of dairy cattle under a semi-intensive rearing system were evaluated; 95 samples were isolated from calves with diarrhea up to the first month of life, 62 males and 33 females, during the rainy season., Results: The presence of virulence genes of E. coli strains was more prevalent in males; the astA (89.47%), st (83.15%), and f 5 (57.89%) genes were more expressed, and the lt (17.89%) and stx 2 (1.05%) genes were less expressed. The eae gene (21.05%) was more present in females., Conclusion: When E. coli strains express virulence genes astA , st, and f 5 and their atypical double, triple, and quadruple combination between different observed pathotypes, they give rise to the formation of several pathotypes by the horizontal transfer of virulence genes, which can cause colibacillosis processes in more virulent calves, which is one of the most important causes of diarrhea in calves in the region of Cajamarca, compromising the sanitary viability in the herds., Competing Interests: The authors declare that they have no conflicts of interest.

Background: Pseudomonas aeruginosa is a highly antimicrobial-resistant pathogen with a very narrow range of effective antibacterial agents. Therefore, finding alternative compounds is highly required, such as silver nanoparticles (AgNPs)., Aim: The current study was conducted to identify the multidrug resistance (MDR) profile and perform a phylogenetic analysis on P. aeruginosa isolates recovered from clinical samples (human, cows, cats, and fish) and to study their susceptibility to AgNPs., Methods: 40 samples were subjected to conventional cultivation and biochemical analyses to identify P. aeruginosa . Moreover, these isolates were tested for their antibiotic resistance profile and their response to AgNPs using disk diffusion methods. PCR and Sanger-based sequencing were performed using the 16S rRNA gene as a target., Results: The results showed that all isolates were resistant to cefixime and sensitive to meropenem. Conversely, the AgNPs were effective in producing larger zones of inhibition. The PCR revealed amplification of the target, and the sequencing and phylogenetic tree of four isolates revealed close similarity with global human sequences from different regions., Conclusion: The study reveals the MDR characteristics of P. aeruginosa . The isolates are highly susceptible to silver nanoparticles., Competing Interests: All authors of the present study ensure that this investigation has no conflict of interest.

Background: Bartonella bovis is one of the most neglected fastidious intracellular bacterial pathogens that infect a wide range of wild and domestic animals, including cattle., Aim: Detection of the prevalence of B. bovis in cattle using molecular assay, identification of the relationship of infection to animal risk factors (age and sex), and sequencing of B. bovis isolates to be analyzed phylogenetically and reported in the National Centre For Biotechnology Information (NCBI)., Methods: A total of 290 cattle were selected randomly from different rural areas in Wasit province from September to December (2023), and subjected to collecting venous blood samples that were tested molecularly by the polymerase chain reaction (PCR). Phylogenetic analysis was conducted using the MEGA 7 Software., Results: Targeting the 16S rRNA gene, 7.24% of the study cattle tested positive for B. bovis . In terms of age, positivity rates, odds ratios (ORs), and relative risks (RRs) were significantly higher in cattle older than 7 years compared to other age groups: under 1 year, 1-3 years, and 3-7 years. Regarding sex, there was no significant variation in positive rates between females (7.48%) and males (5.56%); however, the OR and RR values indicated that females (1.376 and 1.345, respectively) were at a higher risk of B. bovis infection than males (0.727 and 0.743, respectively). Phylogenetic tree analysis of five local B. bovis isolates demonstrated their identity with the France strain/isolate at total genetic identity ranging from 99.64% to 99.98%., Conclusion: To the best of our knowledge, this study represents the first molecular identification of the prevalence rate of B. bovis in cattle in Iraq using PCR assay and confirms phylogenetically the local B. bovis isolates in NCBI-BLAST. Therefore, additional information about the prevalence, genetic diversity in domestic and wild animals, and arthropod vectors is crucial for developing strategies for the prevention and control of B. bovis infections., Competing Interests: There is no conflict of interest.

Background: Ticks are vectors of pathogens that affect the health of animals and humans. With the constant trade of livestock across borders, there is the risk of new tick species invasion accompanied by the spread of infectious tick-borne pathogens., Aim: This study sought to determine the diversity of tick species within abattoirs and a slaughter slab as well as identify the pathogens carried by these ticks., Methods: The ticks were collected from slaughtered cattle, identified and screened for pathogens using PCR and sequencing., Results: A total of 371 ticks were collected from slaughtered cattle across the three sampling sites: Kumasi abattoir (288, 77.63%), Akwatia Line slaughter slab (52, 14.02%) and Suame abattoir (31, 8.35%). The predominant species was Amblyomma variegatum (85.44%) with Rhipicephalus sanguineus (s.l.) (0.27%) as the least occurring species. Total nucleic acid from the tick pools was screened for pathogens based on the nucleoprotein gene region in the S segment of the Crimean-Congo haemorrhagic fever virus (CCHFV) genome, the 295-bp fragment of the transposase gene of the Coxiella burnetii IS1111a element, the 560 bp segment of the ssrRNA gene of Babesia and Theileria, the 345 bp fragment of the Ehrlichia genus 16SrRNA gene and the rOmpA gene (OmpA) of Rickettsia. From the 52 tick pools screened, 40 (76.92%) were found positive for pathogen DNA. The pathogens identified were Rickettsia africae (69.23%), Rickettsia aeschlimannii (7.69%), C. burnetii (5.77%), uncultured Ehrlichia sp. (5.77%), Candidatus Midichloria mitochondrii (3.85%) and CCHFV (3.85%). A significant association was observed among A. variegatum, Hyalomma rufipes, Hyalomma truncatum and occurring tick-borne pathogens R. africae, R. aeschlimannii and uncultured Ehrlichia sp. (p < 0.001)., Conclusion: The findings show the occurrence of zoonotic pathogens, suggesting an increased risk of infections among the abattoir workers. There is a need to adopt control measures within the abattoirs to prevent pathogen spread., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Clostridium sp. was detected in the organs of a cow with black watery diarrhea in Japan. Results identifying this species were inconsistent; Clostridium novyi type A infection was suggested by PCR assay targeting Clostridium fliC region (fliC-multiplex PCR), while 16S rRNA gene sequencing identified the isolated bacteria as Clostridium massiliodielmoense. Sequencing of fliC-multiplex PCR products from the isolates revealed the presence of fliC region in C. massiliodielmoense, which had 92.7% nucleotide similarity to that of C. novyi type A JCM 1406 T , leading to the false positive detection of C. novyi by the PCR. This is the first C. massiliodielmoense isolation from clinical specimens, suggesting the need for further research on its pathogenicity and improvement in fliC-multiplex PCR.

Leptospirosis, a neglected zoonotic disease, adversely affects animal, human health, and socioeconomic conditions, particularly in developing countries like Nigeria. This study aimed to determine the occurrence and molecular identification of pathogenic Leptospira spp. among abattoir workers, cattle, and rats in Jos North, Plateau State, Nigeria. Using a cross-sectional study design, a total of 394 samples were collected, including 149 urine samples from abattoir workers, 125 urine samples from cattle bladders, and 120 bladders from trapped rats. Samples were processed and cultured in Ellinghausen McCullough Johnson Harrison (EMJH) medium and examined under a darkfield microscope. Positive cultures were confirmed using the Microscopic Agglutination Test (MAT) and nested Polymerase Chain Reaction (N-PCR) targeted the 16 S rDNA gene. Results revealed a prevalence of 33.76 % for Leptospira spp. across all samples, with the highest occurrence in abattoir workers (13.96 %), followed by rats (13.45 %), and cattle (6.35 %). The MAT showed L. interrogans serovar Hardjo str. Hardjoprajitno as the most prevalent serotype (41.61 %), followed by L. interrogans serovar Icterohaemorrhagiae str. RGA (34.31 %). N-PCR confirmed the presence of pathogenic Leptospira spp., showing bands of 1200 bp. Phylogenetic analysis of the 16 S rDNA gene sequences revealed close similarities to known pathogenic Leptospira strains from Brazil and the USA. The study underscores the significant public health risk posed by leptospirosis in Jos North and highlights the need for improved diagnostic capabilities, increased awareness, and effective control measures to mitigate the disease burden. Enhanced surveillance and preventive strategies are crucial to protect both animal and human health in the region., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A simple IgG-specific ELISA for Leptospira spp. was compared with the microscopic agglutination test (MAT) to detect IgG antibody responses to a commercial vaccine in cattle. We used an enzyme-linked immunosorbent assay (ELISA) with sonicated Leptospira interrogans serovar copenhageni M 20. After initial vaccination, specific antibodies against Leptospira spp. were detected in 90 % of the animals by IgG-ELISA and 60 % by MAT, while after booster, antibodies were detected in 100 % and 80 % of the animals by IgG-ELISA and MAT, respectively. Both serological MAT and ELISA tests revealed interferences of vaccine antibodies. Disease diagnosis with ELISA and MAT methods should be made two and a half months and four months, respectively, after vaccination to avoid interference of vaccine antibodies. On the other hand, our results suggest that IgG-ELISA may be a useful method to assess the development of IgG antibodies induced by Leptospira vaccine., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024. Published by Elsevier B.V.)

Due to its increasing occurrence in cattle farms in various countries, leading to significant economic losses in affected livestock, Salmonella enterica subspecies enterica serovar Dublin (S. Dublin) has become a highly investigated pathogen in cattle production. In Austria, there have been occasional human cases of S. Dublin as well as an increase in laboratory-confirmed cases in cattle, indicating the need for a screening programme to determine the current status in Austria. The aims of this study were, firstly, to determine the seroprevalence of S. Dublin in dairy herds through bulk milk screenings in two federal states (Salzburg, Tyrol) of Austria. Secondly, the study aimed to identify the infection status of the herds through individual animal and herd level detection, comparing microbiological, molecular and serological detection methods. The results of the study will allow the development of a sampling strategy for a surveillance programme in Austria. A total of 6973 dairy farms were tested through serological bulk milk screening. The seroprevalence for the federal state of Tyrol was 14.8 % and for Salzburg it was 18.2 %, resulting in an average seroprevalence of 16.5 %. At an individual animal level, 205 (11.3 %) animals tested positive for shedding of S. Dublin in the faeces through microbiological detection, and 268 (17.0 %) animals had positive values (ct value ≤ 38) by qPCR. The association between microbiological and molecular detection was statistically significant (p < 0.001), with a calculated kappa value of 0.65 ± 0.27 (p ≤ 0.001), assuming a substantial level of agreement. In 17 herds, where an individual animal tested positive for shedding of S. Dublin, environmental sampling and testing were carried out. At a herd level 16 (94.1 %) out of the 17 participating herds, tested positive for S. Dublin either microbiologically or by molecular assay in boot swab samples. Bulk milk samples from 14 out of the 17 participating herds were analysed for antibodies to S. Dublin and 12 samples (85.7 %) were positive. In total 111 (18.9 %) out of 587 blood samples tested positive for S. Dublin antibodies, demonstrating a statistically significant correlation (p < 0.001) both with microbiological (κ = 0.32 ± 0.49; p ≤ 0.001) and molecular (κ=0.23 ± 0.06; p ≤ 0.001) findings. It was possible to identify S. Dublin by culture from boot swabs in 14 (82.4 %) out of 17 herds and by molecular assay using qPCR in 15 (88.2 %) out of 17 herds, indicating a suitable sample type for screening on a herd level-basis for acute infections, but not for identifying chronic infections or asymptomatic carriers. Other environmental samples, such as sponge-sticks, are only suitable to a limited extent for the detection of S. Dublin. The results of this study demonstrate a moderate S. Dublin prevalence in dairy herds in the selected Austrian regions, signalling further screening and management programmes for the future., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kerstin Hofer reports financial support was provided by Austrian Agency for Health and Food Safety (AGES). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Salmonellosis is an infectious disease caused by bacteria belonging to the Salmonella genus. Bovine salmonellosis is more frequent in young cattle under intensive overcrowd husbandry conditions, and therefore uncommon in adults. We report four outbreaks of clinical salmonellosis due to Salmonella Typhimurium, Salmonella Newport and Salmonella Dublin provoking outbreaks of diarrheic/septicemic disease in adult cattle of Central Argentina. Anamnesis information, clinical, pathological, and bacteriological findings were retrospective analyzed. This report emphasizes the importance to include salmonellosis among the differential diagnosis of clinical enteric/septicemic disease in adult cattle under different husbandry conditions in Argentina. The source of Salmonella could not be established in these outbreaks., (© 2024. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)