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Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Klebsiella pneumoniae is an opportunistic pathogen causing nosocomial infections, classified into carbapenem-sensitive and carbapenem-resistant strains. Understanding the virulence factors and antibiotic resistance of these strains is essential for effective clinical management., Objective: This study compared the virulence genes and antibiotic resistance profiles of 50 CSKP and 50 CRKP strains, examining their expression under antibiotic pressure and the mechanisms contributing to their pathogenicity., Methods: Virulence genes ( rmpA , rmpA2 , iucA , iutA , Peg-344 , ybts , iroB ) were detected in both strains using polymerase chain reaction (PCR). Antibiotic susceptibility testing established minimum inhibitory concentrations (MICs) for key antibiotics. Gene expression analysis was performed with quantitative reverse transcription PCR (qRT-PCR) after 10 days of antibiotic exposure., Results: CSKP strains exhibited significantly higher positivity rates for virulence genes compared to CRKP strains. CRKP strains predominantly expressed resistance genes KPC , SHV , and CTX-M3 , whereas no resistance genes were found in CSKP. Antibiotic susceptibility tests showed increased MICs, particularly for ciprofloxacin and imipenem, following antibiotic induction. CSKP demonstrated elevated expression of rmpA and rmpA2 , while CRKP showed increased expression of SHV , and KPC after antibiotic exposure., Conclusion: This study highlights the intricate relationship between virulence and resistance in Klebsiella pneumoniae . CSKP strains show strong virulence factor expression, while CRKP strains adapt to antibiotic pressure through altered gene expression patterns. These findings underscore the urgent need for continuous surveillance and innovative therapeutic strategies to combat multidrug-resistant Klebsiella pneumoniae infections., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Chen, Zhang and Li.)

Campylobacter jejuni (C. jejuni) is a leading foodborne illness causing bacteria, and poultry is a major reservoir of this pathogen. With the recent increase in broiler production under the "no antibiotics ever" (NAE) system, this study aimed to assess the prevalence, antibiotic resistance, and virulence characteristics of C. jejuni isolated from NAE raised broilers. A total of 270 cloacal swabs were collected from the live-hang areas of 3 commercial processing plants over 9 wk. Each processing plant was visited 3 times at a 1-wk interval, and 30 samples were collected per visit. Among the total 270 cloacal swab samples, C. jejuni was isolated from 44 (16.3%) samples . Of these isolates, 65.9% possessed toxin-producing genes cdtA, cdtB, and cdtC, and invasion gene ciaB. The prevalence of antibioitc resistance genes aph (3')-IIIa, erm(B) were 59.1%, and 50%, respectively. Nine (20.45%) C. jejuni isolates were identified as multidrug resistant (MDR), and 18 (40.9%) isolates showed resistance to at least 1 tested antibiotic. The highest resistance was observed against tetracycline (29.5%), followed by nalidixic acid (25%), whereas 22.7% of isolates were resistant to 2 clinically important antibiotics, azithromycin and ciprofloxacin. These results suggest that there ishigh prevalence level of multi-drug resistant C. jejuni with toxin producing virulence genes in the NAE-raised broilers sampled in this study, indicating the potential for serious human illnesses if transmitted through the food chain., Competing Interests: DISCLOSURES The authors have declared no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Moth orchids ( Phalaenopsis spp.) are globally popular ornamental flowers. However, effective management strategies for Phalaenopsis leaf yellowing remain elusive, making the disease a challenging obstacle affecting moth orchids at various growth stages. This disease manifests as collar rot, leaf yellowing, leaf abscission, and eventually, plant death. The lack of effective management strategies is likely attributed to a limited understanding of the disease pathogenesis and pathogen dissemination pathways. Fusarium phalaenopsidis sp. nov. was established in this study to stabilize the classification status of Phalaenopsis leaf yellowing pathogens using molecular and morphological features. The genome of the holotype strain was sequenced and assembled, revealing its genome structures. Analyses of virulence-related elements, including transposon elements, secondary metabolite biosynthetic gene clusters, effectors, and secreted carbohydrate-active enzymes, shed light on the potential roles of three fast core chromosomes in virulence. Two species-specific primers were designed based on unique gene sequences of two virulence-related proteins through comparative genomics and BLAST screening. The specificity of these primers was validated using isolates of F. phalaenopsidis , non-target species in the Fusarium solani species complex, other Fusarium species complexes, and saprophytic fungi. These results are intended to accelerate the identification of the pathogens, facilitate the study of disease pathogenesis, and pave the way for elucidating pathogen dissemination pathways. Ultimately, they aim to contribute to the formulation of effective control strategies against Phalaenopsis leaf yellowing., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Tsao, Li, Tu, Nai, Lin and Wang.)

Streptococcus agalactiae ( Strep. agalactiae ) is bovine mastitis pathogen and has thus became a matter of concern to dairy farms worldwide in terms of economic loss. The aims of this study were to (a) determine virulence genes, and (b) characterize the antimicrobial resistance (AMR) profiles and AMR genes and (c) figure out the relationship between AMR phenotypes and genotypes of Strep. agalactiae isolated from dairy cows in north China. A total of 20 virulence genes and 23 AMR genes of 140 isolates collected from 12 farms in six provinces were studied. The antimicrobial susceptibility of 10 veterinary commonly used antimicrobials were tested using the broth microdilution method. Results showed that all the isolates harbored the virulence genes lac IV, gapC , and dltA . The isolates that harbored the genes lacIII , fbsA , hylB , and cfb exhibited the high prevalence (99.29%), followed by isolates that harbored lac I (98.57%), bibA (97.86%), cylE (97.14%), lac II (92.14%), cspA (52.14%), pavA (25%), bca (2.14%), and scpB (0.71%). The fbsB , lmb , spbI , bac , and rib genes were not detected. The virulence patterns of B ( fbsA _ cfb _ cylE _ hylB _ bibA _ cspA _ gapC _ dltA _ lacIII/IV ) and C ( fbsA _ cfb _ bibA _ gapC _ dltA _ lacIV ) were dominant, accounting for 97.86% of the isolates. The following AMR genes were prevalent: pbp1A (97.14%), tet (M) (95.00%), lnu (A) (80.71%), erm (B) (75.00%), tet (O) (72.14%), blaZ (49.29%), tet (S) (29.29%), blaTEM (25.71%), erm (A) (17.14%), erm (C) (13.57%), tet (L) (10.71%), linB (2.86%), and erm (TR) (2.86%). The pbp2b , mecA1 , mecC , lnu (D), erm (F/G/Q), and mef (A) genes were not detected. Eighty percent of the isolates harbored AMR genes and were highly resistant to tetracycline, followed by macrolides (10.71%), lincosamides (9.29%) and β-lactams (4.29%). In conclusion, isolates only exhibited well correlation between tetracyclines resistance phenotype and genotype, and almost all isolates harbored intact combination of virulence genes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Liu, Liu, Yang, Gu, Zhang and Qu.)

ObjectiveTo satisfy the demands of laboratory quality control and proficiency testing for the detection of enteroinvasive Escherichia coli (EIEC), a stable EIEC reference material was developed with independent intellectual property rights, good stability and clear background genomic information.MethodsNGS Technique was used to sequence the whole genome of enteroinvasive Escherichia coli (CMCC 44840), bioinformatics analysis was performed to identify the species, serotype, MLST type and virulence genes; EIEC lyophilized samples with 103 CFU were prepared by freeze-drying method ; The homogeneity test was performed according to CNAS-GL017, and the result were statistically analyzed by one-way ANOVA; The samples were stored at -20, 4, 25 and 37 ℃, respectively, and their storage stability and transport stability were evaluated; Five kinds of food matrix samples were used to verify the applicability of reference materials, and three laboratories were organized for collaborative calibration.ResultsThe genome size of CMCC 44840 was 4.96 Mb, the GC content was 50.7%, and the genome contained 5424 coding genes. This strain was identified as the species of Escherichia coli, and the serotype and the MLST type were predicted to be O28ac: H7 and ST311, respectively, and it carried ipaH, virB, virF and other virulence genes. The homogeneity test result of the EIEC lyophilized sample was F=1.79, which met the homogeneity requirements of reference materials. The EIEC samples were still 103 CFU when storing at -20 ℃ and 4 ℃ for 60 d and storing at 25 ℃ and 4 ℃ for 7 d, and decreased on the third day at 37 ℃. EIEC were detected in 20 different food matrix samples with EIEC lyophilized samples after enrichment. The samples were 103 CFU determined by three collaborative calibration laboratories, and there were no significant differences among these laboratories (F=0.59).ConclusionThe EIEC reference material prepared in this study has clear genome sequence information. The homogeneity and stability meet the requirements and have good applicability, which can meet the requirements of quality control and capability verification in food testing laboratory.

Abstract Background Streptococcus pneumoniae (S. pneumoniae) is the common cause of community-acquired pneumonia (CAP) and is also found in the upper respiratory tract of healthy people. Hence, the study aimed to compare the serotypes, virulence/pili genes, and antibiotic susceptibility of S. pneumoniae from healthy asymptomatic participants and CAP patients. Methods Streptococcus pneumoniae were retrospectively collected from health asymptomatic participants and CAP patients in Sichuan, China. The serotypes were tested by multiplex polymerase chain reaction (PCR) or Quellung reaction. Antibiotic susceptibility testing was performed using the broth microdilution method. The molecular epidemiology of S. pneumoniae was analyzed by multilocus sequence typing (MLST). Additionally, the presence of virulence/pili genes were detected using PCR. Results A total of 83 pneumococcal isolates were collected in the current study. Of these, 52 and 31 isolates were from healthy asymptomatic participants and CAP patients, respectively. Most of S. pneumoniae were resistant to erythromycin (ERY), clindamycin (CLI), tetracycline (TET) and trimethoprim-sulfamethoxazole (SXT). 90.4% isolates were classified as multidrug resistant (MDR). The predominant serotypes were 3, 19F and 19A in the CAP carriers, whereas 3, 6 and 19F were the main serotypes among the asymptomatic carriers. The overall coverage rates of pneumococcal conjugate vaccine (PCV) 10 and PCV13 serotypes were 34.9% and 66.3%, respectively. The predominant sequence types (STs) were ST271, ST320, and ST3397. There were significant differences in some resistance and virulence characteristics between CAP patients and asymptomatic carriers. Additionally, clonal complex (CC) 271 strains had higher percentage in resistance to cefuroxime (CXM) and cefotaxime (CEF), meropenem (MER) and cefepime (CFP), which mainly carried the rlrA and sipA genes. Conclusions High coverage rate of PCV13 and high prevalence of MDR indicated the necessity to expand immunization with PCV13 and rationally use the antibiotics in Sichuan, China. Importantly, long-term surveillance should be conducted to assess effectiveness brought by vaccines. Our findings may supply new guidance for developing new pneumococcal vaccines.

ObjectiveThe study aims to analyze the drug resistance, virulence genes and molecular typing of Vibrio parahaemolyticus (VP) identified in Zaozhuang from 2019 to 2020.MethodsThe VP strains were isolated and identified, following the Vibrio parahaemolyticus test protocol in the National Food Safety Standard (GB 4789.7—2013). The broth microdilution method was performed to determine the resistance of VP to 12 antibiotics. Their virulence genes (tlh, tdh, trh) were detected by real-time quantitative polymerase chain reaction (PCR). Pulsed field gel electrophoresis (PFGE) was applied for molecular typing, and the strain clustering was analyzed by BN software. The chi-square test was used to analyze the statistical result (α=0.05).ResultsThe detection rate of VP was 4.57% out of 678 patients’ stool samples. Among the 31 identified VP strains, the resistance rate to cefazolin was 58.06%, and the multi-drug resistance rate was 12.90%. The positive rates of virulence genes tlh, tdh, trh were 100%, 96.78%, 3.22% respectively. The 31 VP strains were further divided into 17 band types and 2 band clusters. The dominant band type cluster covered 93.55% of the strains.ConclusionThe VP strains in Zaozhuang from 2019 to 2020 were highly resistant to cefazolin. Some strains showed multiple drug resistance. They mainly carry two virulence genes, tdh and tlh. The PFGE bands were well-clustered, suggesting high homology among these VP strains. Epidemiological investigation and tracing of VP strains should be strengthened in this region.

Abstract Escherichia coli has become one of the most important causes of calf diarrhea. The aim of this study is to determine the patterns of antimicrobial resistance of E. coli isolates from six cattle farms and to identify prominent resistance genes and virulence genes among the strains isolated from the diarrhea of calves. Antimicrobial susceptibility tests were performed using the disk diffusion method, and PCR was used to detect resistance and virulence genes. The prevalence of multidrug resistant (MDR) E. coli was 77.8% in dairy cattle and 63.6% in beef cattle. There were high resistance rates to penicillin (100%, 100%) and ampicillin (96.3%, 86.4%) in E. coli from dairy cattle and beef cattle. Interestingly, resistance rate to antimicrobials and distribution of resistance genes in E. coli isolated from dairy cattle were higher than those in beef cattle. Further analysis showed that the most prevalent resistance genes were bla TEM and aadA1 in dairy cattle and beef cattle, respectively. Moreover, seven diarrheagenic virulence genes (irp2, fyuA, Stx1, eaeA, F41, K99 and STa) were present in the isolates from dairy cattle, with a prevalence ranging from 3.7% to 22.22%. Six diarrheagenic virulence genes (irp2, fyuA, Stx1, eaeA, hylA and F41) were identified in the isolates from beef cattle, with a prevalence ranging from 2.27% to 63.64%. Our results provide important evidence for better exploring their interaction mechanism. Further studies are also needed to understand the origin and transmission route of E. coli in cattle to reduce its prevalence.

Offshore industries and resources are the links between humans and the marine ecosystem. Several risk factors are associated with beach activities. The risk of Vibrio infection at bathing beaches is often overlooked as there are virtually no regulations regarding them. In this study, we investigated the current prevalence of pathogenic Vibrio spp. on the main beaches of Shenzhen. The risk indicator levels of pathogenic Vibrio species obtained were analyzed using 17 virulence genes mainly associated with Vibrio species and are responsible for several ailments and infections. A total of 60 Vibrio strains were isolated and identified by morphological observation, evolutionary tree alignment, and biochemical testing. There was a high abundance of Vibrio in the seawater. Also, a positive correlation was observed between the presence of virulence genes and the exhibition of high pathogenicity after artificially infecting fish with some of the virulent Vibrio species. In the infection experiment, it was observed that all the zebrafish infected with MEDF7 (Vibrio alginolyticus) and JSW-YELLOW (Vibrio harveyi) died a day after injection, with varying degrees of abdominal enlargement and skin ulceration. The mortality rates for strains with medium risk and low risk were 65% and 45%, respectively. Lethal dose 50 (LD50) values were 5.67 ×104 CFU/fish, 3.72 ×105 CFU/fish, and 4.31 ×105 CFU/fish for the high-risk, medium-risk, and low-risk strains of zebrafish, respectively. The results of the antibiotic sensitivity test showed that all the six experimental strains, except JSW-YELLOW, were resistant to doxycycline and neopenicillin. In summary, our study first identified and evaluated the pathogenicity of Vibrio in the Shenzhen beach baths, serving as a scientific benchmark for Vibrio risk prevention and control as well as guidance for Vibrio diagnosis through virulence factor detection and risk classification.

Whole-genome sequencing (WGS) was used for the genomic characterization of one hundred and ten strains of Listeria innocua (L. innocua) isolated from twenty-three cattle farms, eight beef abattoirs, and forty-eight retail outlets in Gauteng province, South Africa. In silico multilocus sequence typing (MLST) was used to identify the isolates’ sequence types (STs). BLAST-based analyses were used to identify antimicrobial and virulence genes. The study also linked the detection of the genes to the origin (industries and types of samples) of the L. innocua isolates. The study detected 14 STs, 13 resistance genes, and 23 virulence genes. Of the 14 STs detected, ST637 (26.4%), ST448 (20%), 537 (13.6%), and 1085 (12.7%) were predominant, and the frequency varied significantly (p < 0.05). All 110 isolates of L. innocua were carriers of one or more antimicrobial resistance genes, with resistance genes lin (100%), fosX (100%), and tet(M) (30%) being the most frequently detected (p < 0.05). Of the 23 virulence genes recognized, 13 (clpC, clpE, clpP, hbp1, svpA, hbp2, iap/cwhA, lap, lpeA, lplA1, lspA, oatA, pdgA, and prsA2) were found in all 110 isolates of L. innocua. Overall, diversity and significant differences were detected in the frequencies of STs, resistance, and virulence genes according to the origins (source and sample type) of the L. innocua isolates. This, being the first genomic characterization of L. innocua recovered from the three levels/industries (farm, abattoir, and retail) of the beef production system in South Africa, provides data on the organism’s distribution and potential food safety implications.

Globally, avian colibacillosis is a leading cause of morbidity and mortality in poultry, associated with economic losses and welfare problems. Here, clinical avian pathogenic E. coli isolates (CEC; n = 50) and faecal E. coli isolates from healthy (FEC; n = 187) Australian meat chickens collected between 2006 and 2014 were subjected to antimicrobial susceptibility testing, phylogenetic grouping, plasmid replicon (PR) typing, multilocus sequence typing, and virulence gene (VG) profiling. Extended-spectrum cephalosporin (ESC)- and fluoroquinolone (FQ)-resistant E. coli isolates underwent further genetic characterization. Significant proportions of CEC and FEC were, respectively, susceptible (13/50; 48/187) or MDR (9/50; 26/187) to 20 tested antimicrobials. Phylogenetic groups A and C, and PR types IncFIB and IncFrep were most represented. Five tested CEC-associated VGs were more prevalent in CEC (≥ 90%) than FEC (≤ 58%). Some isolates (CEC n = 3; FEC n = 7) were resistant to ESCs and/or FQs and possessed signature mutations in chromosomal FQ target genes and plasmid-mediated qnrS, blaCMY-2, and blaDHA-1 genes. Sequence type 354 (n = 4), associated with extraintestinal infections in a broad range of hosts, was prevalent among ESC- and/or FQ-resistant FEC. This study confirmed existence of a small reservoir of ESC- and FQ-resistant E. coli in Australian commercial meat chickens despite absence of use in the industry of these drugs. Otherwise, diversity of VGs and PR types in both FEC and CEC populations was identified. We hypothesize that the source of ESC- and FQ-resistant E. coli is external to poultry production facilities. Low-level resistance to older and newer generation antimicrobial drugs detected. The most common sequence type (ST) associated with FQ resistance was ST354 (4/10). A small proportion of CEC (n = 3) and FEC (n = 7) were resistant to ESCs and/or FQs. [ABSTRACT FROM AUTHOR]

Verticillium dahliae is a soilborne fungus that causes Verticillium wilt disease in a plethora of crops. Based on symptoms that develop on cotton, olive and okra, V. dahliae isolates are categorized into two pathotypes, namely defoliating and nondefoliating, with the former showing increased virulence and causing severe defoliation. Reliable differentiation between V. dahliae pathotypes is crucial for the management of Verticillium wilt in cotton and olive. In the present study, a polymorphism was detected among isolates of defoliating and nondefoliating pathotypes in Southern blots using the VdNEP gene as a probe. The regions flanking this gene were isolated by inverse PCR and sequence differences in the 3′ untranslated region (3′‐UTR) of the VdNEP gene were detected between the two pathotypes. Based on these sequences, primers were designed and assessed to develop a multiplex PCR detection assay. Using this assay, a collection of cotton and olive V. dahliae isolates from Greece and Cyprus was screened, revealing that the defoliating pathotype is present in several regional units of Greece. Thus, this work presents a new, sensitive molecular marker for the differentiation between V. dahliae pathotypes based on the VdNEP gene. Because the 3′‐UTR is involved in the phenotypes displayed by the pathotypes, an expression experiment was conducted under conditions simulating the xylem of a host plant. Expression of the VdNEP gene was elevated at all time points in the defoliating compared to the nondefoliating strain, suggesting a possible involvement of VdNEP expression in the defoliation process. [ABSTRACT FROM AUTHOR]

Objective: A novel multidrug resistant (MDR) Escherichia coli (E.coli) strain J2_5 was isolated from a patient’s mid stream urine sample. According to the genome sequence of J2_5, we analyzed its evolutionary classification, drug resistance genes and virulence genes, providing theoretical basis for clinical diagnosis and drug selection for drug resistant bacterial infection. Methods: Genome DNA of J2_5 was isolated and sequenced by high throughput sequencing technology, after analyzed the high throughput sequencing data and compared it with known databases by a variety of bioinformatics tools, a high integrity genome of J2_5 was obtained. Results: The total length of the whole genome of J2_5 was 4.7Mb and GC content was 50.78%. Phylogenetic tree analysis showed that J2_ 5’genome was closely related to that of wild type E. coli strain MG1655. But Multilocus sequence typing (MLST) analysis revealed ST type of J2_5 was ST2491, which was different from that of MG1655 (ST10) . Furthermore, CARD database analysis showed that the genome of J2_5 encodes 65 drug resistance genes, which make the strain obtain drugresistant ability through four different mechanisms (antibiotic efflux pump, antibiotic inactivation, antibiotic target change, reduced permeability to antibiotics) . VFDB database analysis showed that there were 40 virulence genes in 7 categories, encoding adhesive proteins, invasion proteins, autonomic transporters and other toxin proteins. After analyzing the whole genome of J2_5 through the Prophage Hunter online tool, we found that there were three prophages in the genome of J2_5, and a virulence gene was carried by one of the prophages. Conclusion: The whole genome sequencing results showed that J2_5 carries some virulence genes and drug resistance genes, which makes the strain obtain strong pathogenicity and resistance ability to a variety of antibiotics. [ABSTRACT FROM AUTHOR]

Vibrio species are major sea foodborne pathogens that cause gastroenteritis as a serious disease of human public health due to the consumption of undercooked or raw fish. In the current study, a total of 100 fish samples (Nile tilapia, Nile perch, Meagre, and Sea bass) were collected randomly from retail markets in Egypt to investigate the prevalence of Vibrio species. The results revealed that Vibrio species isolated with an overall percentage of 52% of all examined fish. Bacteriological and chemical examinations revealed 42.3% V. parahaemolyticus, 26.92% V. mimicus, 19.23% V. alginolyticus, 9.62% V. vulnificus and 1.92% V. cholera. Antibiotic sensitivity declared high resistance of the isolates to different antimicrobial agents used in Egypt including Ampicillin (100%), Nalidixic acid (88.3%), Streptomycin (84.2%), Sulphamethoxazol (70.7%) and Oxytetracycline (64.8%) and it had sensitivity to Amikacin (94%), Ciprofloxacin (70.5%), Gentamicin (58.9%) with an average MAR index of 0.576. By polymerase chain reaction, all examined Vibrio isolates were positive for 16SrRNA specific for Vibrio spp. and harbored toxR gene virulence gene. Finally, dipping of tilapia in lemon juice 5% for 2 h reduced V. parahaemolyticus count by 0.42log cfu/g (62.08%). Consequently, hygienic measures should be approved to control the contamination of fish in the markets and the aquatic environment. Regular monitoring of fish for antibiotic resistance by Vibrio species, and their molecular characterization is necessary to improve the safety of seafood. Dipping fish in lemon juice is an efficient strategy for reducing V. parahaemolyticus load in fish. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Klebsiella pneumoniae, a leading cause of hospital- and community-acquired infections, requires the acquisition of drug resistance and virulence for survival in evading the host's immune responses. The investigation looks at the molecular diversity of 30 clinical isolates using rep-PCR DNA fingerprinting and the association between drug resistance and virulence genes. MATERIALS AND METHODS: Isolates were cultured using basic bacteriological techniques, while antimicrobial susceptibility test and ID confirmation were made by Vitek 2 Compact Automated System (BioMerieux, Marcy L'Etoile, France). DNA used for PCR reactions was extracted with Qiagen DNA extraction kit according to the manufacturer's guidelines, while molecular genotyping by REP-PCR was carried out according to previously described methods. Some virulence genes and capsular serotypes, ybtS, mrkD, entB, rmpA, K2, Kfu, alls, iutA, and magA, were amplified by multiplex PCR. RESULTS: The majority (60%) of the isolates were MDR, others were XDR (37%) and susceptible strains (3%). Additionally, resistance was high (73%) for meropenem and lower (40%) for imipenem, while 97% were susceptible to ertapenem and azithromycin. DNA fingerprinting by rep-PCR showed polymorphic loci sizes that ranged from 100-2000 bp-, and phylogenetic analysis placed the isolates in seven clades with 40-96%. There was a 75% phylogenetic relatedness to antimicrobial resistance, but no specific pattern of relatedness was seen between virulence genes for the K. pneumoniae strain. Regulator mucoid phenotype A (rmpA) gene was not amplified in any of the isolates. CONCLUSIONS: This study further confirms the presence of both MDR and XDR K. pneumonia strains. Isolates exhibited genetic diversity in phylogenetic patterns and carriage of virulence with relatedness by susceptibility to antimicrobials. Therefore, circulation could pose a risk to public health. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bacillus cereus is a major food-borne bacterial pathogen in the world, which can cause diarrhea and emetic syndrome. This study aimed to reveal the quantitative prevalence of B. cereus in ready-to-eat (RTE) rice products in Eastern China and to gain essential information on the characteristics of B. cereus isolates. A total of 91 out of the 1071 samples were positive for B. cereus. The contamination level of B. cereus in 0.5 % of RTE rice product samples outnumbered 103 CFU/g. The number of B. cereus attained 105-106 CFU/g in one sample. The distribution patterns of virulence genes in B. cereus isolates were identified. 84.6% of the B. cereus isolates had at least one enterotoxin or emetic toxin gene. The predominant pattern was XXV. 9.9% of isolates belonged to it and possessed one enterotoxin gene entFM. The occurrence rate of hblACD and nheABC was 36.3% and 47.3%, respectively. Antimicrobial susceptibility tests revealed a high resistance rate toward penicillin, and 23.1% of the isolates were multidrug resistant. B. cereus isolates were genotyped by using ERIC-PCR. 89 genotypes were determined. The Hunter Gaston Discriminatory Index (HGDI) attained 0.9995. Relationships analysis revealed that Group A B. cereus isolates tended to carry hblA, hblC, hblD, nheA, nheB, and show resistance to penicillin/trimethoprim/sulfamethoxazole. This study was useful for updating the knowledge of the contamination status of B. cereus in RTE rice products in China. [ABSTRACT FROM AUTHOR]

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Microorganisms' survival is based on the importance of growth factors found in the microbial environment, as well as their overwhelming appetite for survival which is controlled by their genetic material. This study was designed to investigate the virulence patterns of Salmonella enterica serovar typhimurium associated with soft cheese. Two hundred and sixty (260) soft cheese samples were collected from vendors at Akure, Ikare and Owo in Ondo State, Nigeria. Molecular characterization of six (6) Salmonella enterica isolates for the possession of iro B, stn, hil A and spv C gene were revealed through multiplex polymerase chain reaction (PCR) analysis with DNA extraction, polymerase chain reaction (PCR) amplification, sequencing and genome blasting, respectively. Results: Four (4) possess only iro B; two (2) possess only stn gene; and another three (3) possess hil A gene as none of the isolates possess spv C gene. This study revealed antibiotic-resistant Salmonella enterica serovar typhimurium is present in locally made soft cheese samples. It also revealed that virulence genes comprising hil A, stn and iro B as well as plasmids-mediating antibiotic resistance are present in S. enterica serovar typhimurium found in locally produced cheese. Conclusions: The presence of molecularly elucidated virulence genes comprising Iro B, Stn and Hil A makes the soft cheese potentially viable for pathogenicity. This study recommends food-borne salmonellosis should be constantly monitored with appropriate cleaning of preparatory paraphernalia in cheese production. Constant sensitization of nomads to improve their awareness on milk-borne zoonosis and its associated risk factors is needed. [ABSTRACT FROM AUTHOR]

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Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Iranian Journal of Veterinary Science & Technology is the property of Ferdowsi University of Mashhad Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Animal Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Jirao Shen, Xiaohu Wu, Yayuan Yang, Yanan Lv, Xinpu Li, Xuezhi Ding, Shengyi Wang, Zuoting Yan, Yong Yan, Feng Yang, Hongsheng Li Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, People’s Republic of ChinaCorrespondence: Feng Yang; Hongsheng Li Tel +86 0391-2115262; +86 0391-2164183Email yangfeng@caas.cn; lihsheng@sina.comObjective: Streptococcus dysgalactiae is a major pathogen in bovine mastitis. The purpose of this study was to survey the prevalence, antimicrobial resistance, as well as the spread of resistance and virulence-associated gene of S. dysgalactiae.Methods: A total of 60 S. dysgalactiae strains were obtained from 830 milk samples from Holstein cows with clinical mastitis. Antimicrobial resistance was examined by the disk diffusion method. Antimicrobial resistance and virulence genes were investigated by PCR, agarose gel electrophoresis and 16S rRNA gene sequencing.Results: All isolates were resistant to tetracycline and showed a high level of resistance to aminoglycoside antibiotics, where 81.67% of the strains were multi-resistant to these ten sorts of antibiotics. In addition, the most prevalent resistance gene in S. dysgalactiae was aphA-1 (98.33%), followed by blaTEM (96.67%), ermB (83.3%), aadA1/aadA2 (78.33%) and tetL (73.33%). Totally, seven virulence genes with 25 combination patterns were detected in these isolates, and each isolates harbored at least one virulence gene. 21.67% of the isolates carried three or more virulence genes, while one strain with seven virulence-related genes and belonged to cfb+lmb+eno+napr+bca+scpB+cyl.Conclusion: These findings indicate that S. dysgalactiae isolated from clinical bovine mastitis cases in Northwest China show a variety of molecular ecology and are highly resistant to antibiotics commonly used in dairy farms. This research will help investigators better understand the pathophysiology S. dysgalactiae in bovine mastitis and choose the appropriate antibiotics to treat mastitis.Keywords: Streptococcus dysgalactiae, bovine mastitis, antimicrobial resistance, virulence gene

Staphylococcus aureus is a well-known pathogen that infects humans and animals. However, information on the fatal respiratory infection in rabbits caused by S. aureus is still limited. In the present study, a S. aureus isolate designated ND01 was recovered from lung samples of rabbits that died of fatal respiratory infection, and the ND01 was characterised by intranasal infection of rabbits, multi-locus sequencing typing, screening virulence genes and testing antimicrobial susceptibility. Clinical signs of matted forepaws and pathological lesions of haemorrhagic tracheitis and necrotising haemorrhagic pneumonia were observed in the ND01 infected rabbits, which were identical to those of naturally infected ones. The sequence type of the ND01 was defined as ST3320 and the ND01 was further grouped into the clonal complex 398. Notably, the ND01 was pvl-positive S. aureus and carried the human-associated scn gene. Moreover, the ND01 was methicillin-susceptible S. aureus and was susceptible to 6 of 10 tested antibiotics. This study described the characteristics of the ND01 causing fatal respiratory infection in rabbits. The results are helpful to further the understanding of the pathogenicity of S. aureus ST3320 clone in rabbits. The results also highlighted that operators must be on the alert for the colonisation of pvl-positive S. aureus in rabbits and potential transmission events between rabbits and humans.

ABSTRACT Antimicrobial therapy plays an important role in mastitis control caused by Staphylococcus aureus but has become less effective due to widespread drug resistance. The purpose of this study was to detect antibiotic resistance, drug resistance gene, and virulence gene of S. aureus strains. In this study, 2,962 milk samples were collected from 43 dairy farms located in 16 provinces of China and cultured for isolation of S. aureus. Antibiotic resistance, capsular polysaccharide, spa typing, virulence genes, and drug resistance genes of the strains were analyzed. Of 2,962 samples, 298 strains were isolated and identified as S. aureus. The strains exhibited high percentages of resistance to penicillin G (91.95%). Moreover, all strains showed resistance to more than one antimicrobial agent but were sensitive to nitrofurantoin and sulfamethoxazole/trimethoprim. The results indicate that type 8 was the dominant capsular polysaccharide serotype and t459 was the dominant spa type. The most prevalent virulence gene was clfA (98%). The resistance genes of several antibiotics were detected, among which the blaZ gene (92.95%) was the highest. In conclusion, we present the antimicrobial resistance and virulence genes of S. aureus in this study which are of importance for mastitis control. IMPORTANCE Bovine mastitis is a serious disease associated with both high incidence and economic loss, posing a major challenge to the dairy industry worldwide. Staphylococcus aureus is one of the most common pathogens to cause bovine mastitis, and antimicrobial therapy plays an important role in mastitis control caused by S. aureus but has become less effective due to widespread drug resistance. The purpose of this study was to detect antibiotic resistance, drug resistance gene, and virulence gene of S. aureus strains, which would be helpful to mastitis control.

ABSTRACT Campylobacter is one of the main bacterial pathogens that cause campylobacteriosis in the United States. Poultry is considered a major reservoir for the transmission of Campylobacter to humans. This study aimed to determine the prevalence and molecular characteristics of Campylobacter in the no-antibiotics-ever (NAE) broilers. A total of 414 samples were collected, among which 160 retail chicken samples were purchased from grocery stores and 254 samples were collected from broiler farms located in Mississippi State. The overall prevalence of Campylobacter was 25.4%, and a significantly higher prevalence was observed in retail chicken than in the farm samples (36.3% versus 18.5%; P

ObjectiveTo investigate the infection status, main virulence genes and drug resistance of diarrheagenic Escherichia coli (DEC) in the diarrhea population in Huzhou, Zhejiang Province.MethodsDECs were isolated from fecal specimens from patients with diarrhea in three sentinel hospitals from 2018 to 2020. All clinical isolates were then further identified using multiplex real-time fluorescence quantitative polymerase chain reaction (PCR). The microbroth dilution method was used for drug sensitivity testing.ResultsA total of 293 DEC positive cases were detected, and 294 strains were isolated. Enteroaggregative Escherichia coli (EAEC) accounted for 55.4% (163/294), and Enterotoxigenic Escherichia coli (EPEC) accounted for 29.6% (87/294). Enteropathogenic Escherichia coli (EPEC) accounted for 11.2% (33/294), Enteroinvasive Escherichia coli (EIEC) accounted for 3.4% (10/294) and Enterohemorrhagic Escherechia coli (EHEC)accounted for 0.3%(1/294). The antimicrobial resistance rates of 117 randomly selected strains to ampicillin, nalidixic acid, ampicillin-Sulbactam and tetracyclin were 70.9%, 60.7%, 53.8% and 51.3%, respectively. The multidrug resistance rate reached 55.6%. The sensitivity rates to imipenem, ceftazidime, amoxicillin clavulanic acid and cefoxitin were 99.1%, 92.3%, 92.3% and 91.5%. DEC cases had a peak in July to August, and the main infected population was between 20 and 39 years old.ConclusionThe DEC genotypes of the patients with diarrhea in Huzhou, Zhejiang Province were mainly EAEC and ETEC, with multiple antibiotic resistance. The distribution of cases was obviously seasonal, and the infected population was mainly young adults.

Objective To investigate the distribution of virulence genes and pathotypes of diarrheogenic Escherichia coli(DEC) from commercial pig farms, providing reference data for prevention and control of foodborne diseases caused by the bacteria from the pork production industry. Methods The virulence genes of Escherichia coli(E. coli), isolated from 12 pig farms, were detected by multiplex real-time quantitative polymerase chain reaction(PCR). Results Among 985 E. coli isolated from pig farms, DEC accounted for 28.83%(284/985), including 225 enteroaggregative E. coli (EAEC, 22.84%, 225/985), 14 enterotoxigenic E. coli (ETEC, 1.42%, 14/985), 12 enteropathogenic E. coli (EPEC, 1.22%, 12/985), 10 enterohemorrhagic E. coli (EHEC, 1.02%, 10/985), 9 enteroinvasive E. coli (EIEC, 0.91%, 9/985), 13 hybrid EHEC-ETEC(1.32%, 13/985), and 1 hybrid EPEC-ETEC(0.10%, 1/985). Among all those strains, one from the nose swab of a breeder had the same EHEC-ETEC virulence genotype as those positive samples detected in pig nose swab and feces. It was also found that the contamination rate of DEC in early fattening stage was significantly higher than that in late fattening stage(χ2=1.10, P

The bacteria pathogen Xanthomonas oryzae pv. oryzae (Xoo) infects rice and causes the severe disease of rice bacteria blight. As the central regulator of the salic acid (SA) signaling pathway, NPR1 is responsible for sensing SA and inducing the expression of pathogen-related (PR) genes in plants. Overexpression of OsNPR1 significantly increases rice resistance to Xoo. Although some downstream rice genes were found to be regulated by OsNPR1, how OsNPR1 affects the interaction of rice-Xoo and alters Xoo gene expression remains unknown. In this study, we challenged the wild-type and OsNPR1-OE rice materials with Xoo and performed dual RNA-seq analyses for the rice and Xoo genomes simultaneously. In Xoo-infected OsNPR1-OE plants, rice genes involved in cell wall biosynthesis and SA signaling pathways, as well as PR genes and nucleotide-binding site-leucine-rich repeat (NBS-LRR) genes, were significantly upregulated compared to rice variety TP309. On the other hand, Xoo genes involved in energy metabolism, oxidative phosphorylation, biosynthesis of primary and secondary metabolism, and transportation were repressed. Many virulence genes of Xoo, including genes encoding components of type III and other secretion systems, were downregulated by OsNPR1 overexpression. Our results suggest that OsNPR1 enhances rice resistance to Xoo by bidirectionally regulating gene expression in rice and Xoo.

The global emergence of hybrid diarrheagenic E. coli strains incorporating genetic markers from different pathotypes is a public health concern. Hybrids of Shiga toxin-producing and enterotoxigenic E. coli (STEC/ETEC) are associated with diarrhea and hemolytic uremic syndrome (HUS) in humans. In this study, we identified and characterized STEC/ETEC hybrid strains isolated from livestock feces (cattle and pigs) and animal food sources (beef, pork, and meat patties) in South Korea between 2016 and 2020. The strains were positive for genes from STEC and ETEC, such as stx (encodes Shiga toxins, Stxs) and est (encodes heat-stable enterotoxins, ST), respectively. The strains belong to diverse serogroups (O100, O168, O8, O155, O2, O141, O148, and O174) and sequence types (ST446, ST1021, ST21, ST74, ST785, ST670, ST1780, ST1782, ST10, and ST726). Genome-wide phylogenetic analysis revealed that these hybrids were closely related to certain ETEC and STEC strains, implying the potential acquisition of Stx-phage and/or ETEC virulence genes during the emergence of STEC/ETEC hybrids. Particularly, STEC/ETEC strains isolated from livestock feces and animal source foods mostly exhibited close relatedness with ETEC strains. These findings allow further exploration of the pathogenicity and virulence of STEC/ETEC hybrid strains and may serve as a data source for future comparative studies in evolutionary biology.

This study investigated the synergistic effects of ε-poly- L -lysine (ε-PL) and lysozyme against P. aeruginosa and L. monocytogenes biofilms. Single-culture biofilms of two bacteria were formed on silicone rubber (SR), stainless steel (SS), and beef surfaces and then treated with lysozyme (0.05–5 mg/mL) and ε-PL at minimum inhibitory concentrations (MICs) of 1 to 4 separately or in combination. On the SR surface, P. aeruginosa biofilm was reduced by 1.4 and 1.9 log CFU/cm2 within 2 h when treated with lysozyme (5 mg/mL) and ε-PL (4 MIC), respectively, but this reduction increased significantly to 4.1 log CFU/cm2 (P < 0.05) with the combined treatment. On beef surface, P. aeruginosa and L. monocytogenes biofilm was reduced by 4.2–5.0, and 3.3–4.2 log CFU/g when lysozyme was combined with 1, 2, and 4 MIC of ε-PL at 25 °C, respectively. Compared to 5 mg/mL lysozyme alone, the combined treatment with 1, 2, and 4 MIC of ε-PL on beef surface achieved additional reduction against P. aeruginosa biofilm of 0.5, 0.8, and 0.7 log CFU/g, respectively, at 25 °C. In addition, 0.25 mg/mL lysozyme and 0.5 MIC of ε-PL significantly (P < 0.05) suppressed the quorum-sensing (agrA) and virulence-associated (hlyA and prfA) genes of L. monocytogenes. • Lysozyme showed antibacterial activity against P. aeruginosa and L.monocytogenes biofilm. • ε-PL was effective to inhibit P. aeruginosa and L.monocytogenes biofilm. • Combination of lysozyme and ε-PL treatment exhibited the highest biofilm reduction against both pathogens. • The combination treatment was effective to reduce virulence and QS-related gene expression. [ABSTRACT FROM AUTHOR]

A case of severe mortality in farmed Labeo rohita was investigated to characterize the causative agent. We identified the bacterial strain as Aeromonas veronii isolated from the gut of infected L. rohita by biochemical assay, scanning electron microscopy and 16S rRNA gene sequence analysis. The in vivo challenge experiment showed that the LD50 of A. veronii was 2.2 × 104 CFU/fish. Virulence gene investigation revealed that the isolated A. veronii possesses Aerolysin, Cytotoxic enterotoxin, Serine protease, Dnase and Type III secretion system genes. The isolated strain was resistant to two antibiotics (ampicillin and dicloxacillin) while susceptible to 22 other antibiotics. The study further revealed that A. veronii induced both stresses along with non-specific and specific immune responses marked by elevated cortisol HSP70, HSP90 and IgM levels in the treated L. rohita fingerlings. Although the bacterial pathogen enhances the immune response, the negative effect on fish, including stress, and high mortality, create concern and a need for A. veronii management in L. rohita farms. The knowledge gained from this study would facilitate future research aimed at assessing the pathogenicity of A. veronii, with an emphasis on microbial disease management in other farmed fish species.

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic pathogen, which causes serious infections in humans and animals. To investigate the antimicrobial resistance pattern and virulence profile of K. pneumoniae , a total of 887 samples were collected from both the healthy and mastitis cows and the bedding, feed, feces, air, drinking water, spraying water, washing water, and milk cup swabs from five dairy farms in Hubei, China, during 2019 and 2020. K. pneumoniae was isolated and identified using PCR of the khe and 16S rDNA sequencing. A genotypic characterization was performed for K. pneumoniae isolates using wzi typing and multilocus sequence typing (MLST). Antimicrobial resistances were confirmed using broth microdilution against 17 antimicrobial agents and resistance and virulence genes were determined by PCR. The prevalence of K. pneumoniae was 26.94% (239/887) distributed in 101 wzi allele types (199/239, 83.26%) and 100 sequence types (STs) (209/239, 87.45%), including 5 new wzi allele type and 25 new STs. Phylogenetic analysis showed that K. pneumoniae isolated from milk, nipple swab, feed, and feces is classified in the same clone complex. By comparing with the PubMLST database, at least 67 STs have the risk of spreading in different species and regions. Interestingly, 60 STs have been isolated from humans. The isolates were highly sensitive to meropenem and colistin, but resistant to ampicillin (100%), sulfisoxazole (94.56%), cephalothin (47.28%), streptomycin (30.13%), and so on. Noteworthy, multidrug-resistant (MDR) rate was found to be 43.93% in this study. By PCR, 30 of 68 antimicrobial resistance (AMR) genes were identified; the prevalence rate of blaTEM , blaSHV , strA , strB , aadA1 , and aac(6′)-Ib-cr was more than 50%. Eleven CTX-M -producing K. pneumoniae were found. The detection rate of fimH , mrkD , uge , wabG , entB , iutA , iroN , and ureA was over 85%. This study reinforces the epidemiological importance of K. pneumoniae in food-producing animals in Hubei. The emergence and spread of environmental MDR K. pneumoniae may pose a potential threat to food safety and public health. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to identify the pathogen causing the death of Chinese grass turtle (Chinemys reevesiis) and identify its biological characteristics, a pathogenic bacterium was isolated from the diseased liver tissue of the dead Chinese tortoise in this study, which was identified as Aeromonas veronii by biochemical identification and named CRQ1. The pathogenicity, virulence genes, drug resistance and drug resistance genes of CRQ1 were detected by zebrafish attack test, PCR and KB susceptibility disk method. The results showed that the LD50 of CRQ1 strain to zebrafish was 3. 57 x107cfu/ml, carrying aerA, act, aha, Ser, Exu, Up, Hly, ompA and LuxS nine virulence genes were found to be sensitive to nine kinds of drugs, including tilmicosin, ciprofloxacin and enrofloxacin, and it was moderately sensitive to eight drugs such as amikacin, streptomycin, and Sulfamethoxypyrimidine, but resistant to neostigmine. The isolates carried let(A), tet(E), oqxA, gyrA, gyrB, parC, parE, aminoglycoside resistance genes aac2, aac(6)-Ib, aadB, aao4, sulfonamide resistant sul-I and macrolide resistance gene emB． However, it did not express the corresponding resistance phenotype, which was related to the duration and frequency of drug use. It is suggested that A veronii is the pathogenic bacteria causing the death of Chinese grass turtle, and it carries virulence genes related to pathogenicity and has potential drug resistance. This study provides a basis for the study of pathogenic mechanism and prevention and control of A. veronii from Chinese grass turtle. [ABSTRACT FROM AUTHOR]

The objective of the current study was to investigate the inhibitory effects of benzyl isothiocyanate (BITC) and 3-(methylthio) propyl isothiocyanate (MTPITC) on Listeria monocytogenes (L. monocytogenes). The comparison of the antibacterial potential of these two sulfur-containing flavors was performed by examining the minimum inhibitory concentration (MIC). Moreover, the relative gene expression levels of the major virulence-related factors in L. monocytogenes with co-incubation with BITC (or MTPITC) were measured using real-time quantitative polymerase chain reaction (RT-qPCR) analysis. In addition, the biofilm-forming rate of L. monocytogenes upon exposure to the tested two compounds was determined. Finally, the changes in the bacterial morphology in the presence of BITC (or MTPITC) were detected with the assistance of scanning electron microscopy. The antimicrobial potential of BITC in resistance to L. monocytogenes growth was much stronger than that of MTPITC. Both of the sulfur-containing compounds remarkably suppressed the gene expressions of inlA, hlyA, and prfA. Besides, these two flavors were capable of changing the formation rate of L. monocytogenes biofilms, whereas only slight wrinkles were observed in the bacterial morphology. Overall, both BITC and MTPITC might be promising antibacterial agents to prevent and control L. monocytogenes. [ABSTRACT FROM AUTHOR]

The urinary tract system has been considered to be one of the body's filtration systems, performing essential excretory functions such as eliminating organic waste compounds, and infection of this system caused by different microbial agents. Samples were collected from patients who were diagnosed with UTI in Al-Salam Teaching Hospital - Mosul throughout the period between January until March 2021. In the present study, a total of one hundred and forty urine and serum samples were collected from patients with UTI, while thirty-four healthy individuals were studied as controls for ELISA test. The current study was designed to isolate and identification of E. coli as the main cause of UTI, the bacterial identified by cultural, biochemical, and further by 16S rRNA. Additionally, studying the prevalence of siderophores (fyuA) virulence gene from isolated E. coli. Finally, measuring the levels of lipocalin-2 (LCN2) in patients with UTI due to E. coli in comparison to the controls group. The results of this study found that the age (mean ± SD) of UTI patients were (32.95 ± 12.80), while in the healthy controls group were (35.55 ± 13.51). Furthermore, the prevalence of women to men was 110 (78.6%) samples referred to female patients, while 30 (21.4%) specimens referred to male patients. Additionally, E. coli were the most common isolated bacteria from the patient with a frequency and percentage of 50 (37.0%). Furthermore, serum LCN2 level was significantly higher in the patient's group due to E. coli with virulence gene compared to the controls group (P<0.001). Moreover, the prevalence of the fyuA gene in E. coli isolates was 49 (98%) were positive. In conclusion, The present study revealed higher serum LCN2 levels in patients with UTIs due to E. coli compared to the controls group. Therefore, LCN2 could be used as a biomarker for UTI. Additionally, the fyuA gene was noticed in 49 (98%) of E. coli isolates, which may has critical role in the pathogenesis of UPEC and increase lipocalin due to siderophores and iron competition. [ABSTRACT FROM AUTHOR]

Laribacter hongkongensis is a new emerging foodborne pathogen that causes community-acquired gastroenteritis and traveler's diarrhea. However, the genetic features of L. hongkongensis have not yet been properly understood. A total of 45 aquatic animal-associated L. hongkongensis strains isolated from intestinal specimens of frogs and grass carps were subjected to whole-genome sequencing (WGS), along with the genome data of 4 reported human clinical strains, the analysis of virulence genes, carbohydrate-active enzymes, and antimicrobial resistance (AMR) determinants were carried out for comprehensively understanding of this new foodborne pathogen. Human clinical strains were genetically more related to some strains from frogs inferred from phylogenetic trees. The distribution of virulence genes and carbohydrate-active enzymes exhibited different patterns among strains of different sources, reflecting their adaption to different host environments and indicating different potentials to infect humans. Thirty-two AMR genes were detected, susceptibility to 18 clinical used antibiotics including aminoglycoside, chloramphenicol, trimethoprim, and sulfa was checked to evaluate the availability of clinical medicines. Resistance to Rifampicin, Cefazolin, ceftazidime, Ampicillin, and ceftriaxone is prevalent in most strains, resistance to tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin, and levofloxacin are aggregated in nearly half of frog-derived strains, suggesting that drug resistance of frog-derived strains is more serious, and clinical treatment for L. hongkongensis infection should be more cautious. [ABSTRACT FROM AUTHOR]

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a common cause of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients, but its infection and colonization state are difficult to distinguish. If the judgment is wrong, it may aggravate the abuse of antibiotics and further accelerate the evolution of drug resistance. We sought to provide new clues for the diagnosis, pathogenesis and treatment of CRAB VAP based on lower respiratory tract (LRT) microbiota. Methods: A prospective study was conducted on patients with mechanical ventilation from July 2018 to December 2019 in a tertiary hospital. Multi-genomics studies (16S rRNA amplicon, metagenomics, and whole-genome sequencing [WGS]) of endotracheal deep aspirate (ETA) were performed. Results: Fifty-two ICU patients were enrolled, including 24 with CRAB VAP (CRAB-I), 22 with CRAB colonization (CRAB-C), and six CRAB-negative patients (infection-free) (CRAB-N). Diversity of pulmonary microbiota was significantly lower in CRAB-I than in CRAB-C or CRAB-N (mean Shannon index, 1.79 vs. 2.73 vs. 4.81, P < 0.05). Abundances of 11 key genera differed between the groups. Acinetobacter was most abundant in CRAB-I (76.19%), moderately abundant in CRAB-C (59.14%), and least abundant in CRAB-N (11.25%), but its interactions with other genera increased in turn. Metagenomics and WGS analysis showed that virulence genes were more abundant in CRAB-I than in CRAB-C. Multi-locus sequence typing (MLST) of 46 CRAB isolates revealed that the main types were ST208 (30.43%) and ST938 (15.22%), with no difference between CRAB-I and CRAB-C. Conclusion: Lower respiratory tract microbiota dysbiosis including elevated relative abundance of Acinetobacter and reduced bacterial interactions, and virulence enrichment may lead to CRAB VAP. [ABSTRACT FROM AUTHOR]

Arcobacter butzelri is known as the cause of enteritis, abdominal cramps, bacteremia, and appendicitis in humans, it is also the cause of enteritis and abdominal pain in animals. It has been introduced as the most dangerous species for human health by the International Committee on Food Microbiology and recently as an important zoonotic pathogen. The aim of this study was isolatation and characterization of Arcobacter butzelri based on pathogenic genes (tlyA, ciaB, mviN) in different seasons. Therefore, 238 samples were collected from the effluent of poultry slaughterhouse in Tonekabon, Iran. The suspected colonies were identified using biochemical test and then confirmed using the Polymerase chain reaction (PCR) technique. Out of 42 isolated of A. butzleri, the virulence genes were detected in 15 isolates. The results showed that ciaB gene was present in 13 strains with a frequency of 30.9%, mviN in 11 samples with a frequency of 26.2%, and tlyA gene in 9 samples with a frequency of 21.4%. The results also revealed that the highest frequency of A. butzelri was 8.4% in spring and the lowest rate was 1.2% in winter.

Summary: This study was conducted to determine the phenotypic and genotypic characteristics of multidrug-resistant (MDR) avian pathogenic Escherichia coli (APEC). A total of 54 MDR APEC were divided into 23 serotypes, and O78 (16.6%) was the most frequently observed. The MDR APEC carried β-lactamase–encoding genes (38.9%), integrons (61.6%), plasmid-mediated quinolone–resistant genes (20.4%), tetracycline-resistant genes (79.6%), sulfonamide-resistant genes (40.7%), and chloramphenicol-resistant genes (18.5%). Phylogenetic group D (44.4%), which is associated with extraintestinal strains, was the most frequently observed, but all MDR APEC, including groups A, B1, and B2, carried one or more virulence genes. This study analyzed the phenotypic and genotypic characterization in MDR APEC isolated from broilers with colibacillosis in Korea. It is important to monitor the occurrence of resistance genes in APEC. These bacteria may pose serious therapeutic problems when treating sick broilers. The MDR strains carried by animals and birds can enter the human food chain through the consumption of meat or other animal or poultry products.

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic pathogen, which causes serious infections in humans and animals. To investigate the antimicrobial resistance pattern and virulence profile of K. pneumoniae, a total of 887 samples were collected from both the healthy and mastitis cows and the bedding, feed, feces, air, drinking water, spraying water, washing water, and milk cup swabs from five dairy farms in Hubei, China, during 2019 and 2020. K. pneumoniae was isolated and identified using PCR of the khe and 16S rDNA sequencing. A genotypic characterization was performed for K. pneumoniae isolates using wzi typing and multilocus sequence typing (MLST). Antimicrobial resistances were confirmed using broth microdilution against 17 antimicrobial agents and resistance and virulence genes were determined by PCR. The prevalence of K. pneumoniae was 26.94% (239/887) distributed in 101 wzi allele types (199/239, 83.26%) and 100 sequence types (STs) (209/239, 87.45%), including 5 new wzi allele type and 25 new STs. Phylogenetic analysis showed that K. pneumoniae isolated from milk, nipple swab, feed, and feces is classified in the same clone complex. By comparing with the PubMLST database, at least 67 STs have the risk of spreading in different species and regions. Interestingly, 60 STs have been isolated from humans. The isolates were highly sensitive to meropenem and colistin, but resistant to ampicillin (100%), sulfisoxazole (94.56%), cephalothin (47.28%), streptomycin (30.13%), and so on. Noteworthy, multidrug-resistant (MDR) rate was found to be 43.93% in this study. By PCR, 30 of 68 antimicrobial resistance (AMR) genes were identified; the prevalence rate of blaTEM, blaSHV, strA, strB, aadA1, and aac(6′)-Ib-cr was more than 50%. Eleven CTX-M-producing K. pneumoniae were found. The detection rate of fimH, mrkD, uge, wabG, entB, iutA, iroN, and ureA was over 85%. This study reinforces the epidemiological importance of K. pneumoniae in food-producing animals in Hubei. The emergence and spread of environmental MDR K. pneumoniae may pose a potential threat to food safety and public health.

ABSTRACT Acanthamoeba species are among the most ubiquitous protists that are widespread in soil and water and act as both a replicative niche and vectors for dispersal. They are the most important human intracellular pathogens, causing Acanthamoeba keratitis (AK) and severely damaging the human cornea. The sympatric lifestyle within the host and amoeba-resisting microorganisms (ARMs) promotes horizontal gene transfer (HGT). However, the genomic diversity of only A. castellanii and A. polyphaga has been widely studied, and the pathogenic mechanisms remain unknown. Thus, we examined 7 clinically pathogenic strains by comparative genomic, phylogenetic, and rhizome gene mosaicism analyses to explore amoeba–symbiont interactions that possibly contribute to pathogenesis. Genetic characterization and phylogenetic analysis showed differences in functional characteristics between the “open” state of T3 and T4 isolates, which may contribute to the differences in virulence and pathogenicity. Through comparative genomic analysis, we identified potential genes related to virulence, such as metalloprotease, laminin-binding protein, and HSP, that were specific to the genus Acanthamoeba. Then, analysis of putative sequence trafficking between Acanthamoeba and Pandoraviruses or Acanthamoeba castellanii medusaviruses provided the best hits with viral genes; among bacteria, Pseudomonas had the most significant numbers. The most parsimonious evolutionary scenarios were between Acanthamoeba and endosymbionts; nevertheless, in most cases, the scenarios are more complex. In addition, the differences in exchanged genes were limited to the same family. In brief, this study provided extensive data to suggest the existence of HGT between Acanthamoeba and ARMs, explaining the occurrence of diseases and challenging Darwin’s concept of eukaryotic evolution. IMPORTANCE Acanthamoeba has the ability to cause serious blinding keratitis. Although the prevalence of this phenomenon has increased in recent years, our knowledge of the underlying opportunistic pathogenic mechanism maybe remains incomplete. In this study, we highlighted the importance of Pseudomonas in the pathogenesis pathway using comprehensive a whole genomics approach of clinical isolates. The horizontal gene transfer events help to explain how endosymbionts contribute Acanthamoeba to act as an opportunistic pathogen. Our study opens up several potential avenues for future research on the differences in pathogenicity and interactions among clinical strains.