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Cyprinid herpesvirus 3, also known as koi herpesvirus (KHV), is an important pathogen in common and koi carp Cyprinus carpio, varieties. Two main genotypes of KHV have been reported worldwide that are associated with Asian and European origins. In the USA, outbreaks of KHV diseases have been reported in different states since the early 1990s; however, the diversity of KHV is unknown. In the current study, 67 DNA samples that were extracted from clinical cases of koi tissues that were submitted for diagnosis during KHV outbreaks from 10 different states in the USA from 1999 to 2019 were used to investigate their genetic diversity. The thymidine kinase gene was amplified, sequenced, and used for phylogenetic analysis. Our results showed that the KHV isolates that were collected from the different states were clustered in the two known KHV genogroups, where 31 isolates belonged to the Asian genotype branch and 36 to the European genotype branch. The spatiotemporal analysis demonstrated fluctuation of KHV genotypes in the USA, as the main KHV genotype that was detected in koi in the USA from 1999 to 2013 was the European genotype, whereas the Asian KHV genotype appeared to emerge in the USA in 2008, increasing in incidence until 2019. The current study provides evidence on the genetic diversity of KHV in the USA. Future studies that evaluate the virulence of these genetically diverse isolates is warranted to obtain a better understanding of the epidemiology of this re‐emerging pathogen. This may provide an improved awareness of the current status of KHV and help to control the disease in the koi population in the USA. [ABSTRACT FROM AUTHOR]

The genetic diversity of Vibrio anguillarum pJM1‐like plasmids was investigated. Plasmids were isolated from 18 V. anguillarum serovar O1 strains collected from different geographic locations and fish species. The plasmids were sequenced and compared with the complete sequence of the published virulence plasmid pJM1. All 18 strains contained pJM1‐like plasmids with approximately 65 kbp and all plasmids encoded the virulence genes responsible for the anguibactin iron sequestering system. The plasmids were highly conserved but minor differences were observed in some genes. A single nucleotide polymorphisms (SNPs) analysis showed 0–11 nucleotide variations between each of the 18 plasmids and the pJM1 plasmid. Compared with the sequence of pJM1, nonsynonymous SNPs were identified in fatC, angR, angL, pJM1_p19, and angE. In particular, a mutation found in 15 out of 18 sequenced plasmids in angR has previously been linked to hyperproduction of anguibactin and was found in all the European isolates. However, overall the pJM1‐like plasmids isolated from V. anguillarum serovar O1 exhibited a high degree of conservation regardless of their geographical origin or fish species. [ABSTRACT FROM AUTHOR]

Raw cow-milk has essentially role inbacteria transferring, causing diseases like Escherichia coli (E. coli).The presentstudy has aimed to delineate E. coli virulence gene heat labile (LT) and heat stable (ST) by using Polymerase Chain Reaction (PCR). In terms of methodology, 125 raw cow-milk samples from four suburbs distinct of karbala as Al-Hussainiya, Al-Zebeliya, Al-hindiya and Al-hurr have been gathered and examined from December 2018 to March 2019.Accordingly, E. colihas been distinguished in 51 samples(40.8%), also the study has shown that the E. coli isolated from raw cow-milk is resistant to Ticarcillin (%92.1) followed by TicarcillinClavulanicacid (90.1%), Topramycin (25.4%),Aztreonam (25.4%) and sensitive to Meropenem (100%),Imepenem (100%) and Colistin (%100). It also sensitive to Ciprofloxacin (94.1%) followed byPipracillin / Tazobactam (88.2%) Pipracillin(%82.3), Trimethoprim / Sulfamethoxazole(80.3%),Pefloxacin (78.4%),Cefepime (76.4%), Gentamicin (76.4%), Minocycline (74.5%) and Amicacin (%72.5).As a result, the molecular features of isolatedE. colihas beenperformed by PCR through the use of proper primers. Virulence profile of genes reveals that 2/51(4%)isolates of E. coli harbored LT genes and 7/51 (14%)isolates of E. coliharbored ST genes. The results have also highlighted poor hygienic practices in the study regions, bringing microbiological risks from raw cow-milk, therefore, the study has proposed an improved hygienic practices on processing, production and distribution to ensure the safety of dairy products, safeguarding public health and to emphasis veterinarians or stakeholders’ role in production and distribution. [ABSTRACT FROM AUTHOR]

The prevalence of methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections (BSIs) has increased in many countries, including Ireland. This study aimed to investigate the molecular epidemiology of MSSA causing BSIs in Irish hospitals between 2006 and 2017, when MSSA BSIs increased, to identify any potential patient or pathogen contributing factors. A total of 252 MSSA isolates from patients in Irish hospitals in 2006/2007, 2011 and 2017 underwent spa typing and DNA microarray profiling. Each patient's gender, age, 14-day mortality and epidemiological context of infection were recorded. Significant increases in community-onset (CO) MSSA BSIs and the average patient's age and decreases in hospital-onset (HO) MSSA were identified. Although, extensive genetic diversity was detected amongst the isolates, i.e. 24 multilocus sequence type clonal complexes (CCs)/sequence types and 124 spa types, three CCs (CC30, CC45, CC5) dominated, albeit in different proportions, during the study periods. CC30 declined significantly, in particular spa type t021, and was more common amongst HO-MSSA and CC45 and CC8 increased, particularly spa types t015 and t008, respectively, and were more common amongst CO-MSSA. Five of the seven most frequent spa types were more common amongst CO-MSSA. Although overall multidrug resistance decreased, the prevalence of erm(C) increased significantly and virulence genes decreased, mostly notably egc, tst, scn, sep and fnbB. This study highlights the threat posed by the increasing prevalence of CO-MSSA BSIs and suggests an association with the increasing prevalence of CC45 CO-MSSA, decreasing prevalence of CC30 HO-MSSA, an ageing population and an overall decrease in virulence and resistance genes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Insect pests have evolved various defense mechanisms to combat fungal infection, and fungi have developed multiple strategies to overcome the immune defense responses of insects. However, transcriptomic analysis of fungal strategies for infecting different pests has not been reported. RESULTS: Transcriptomic profiling of Beauveria bassiana was performed at 12, 24 and 48 h after infecting Galleria mellonella and Plutella xylostella, and 540, 847 and 932 differentially expressed genes were detected, respectively. Functional categorization showed that most of these genes are involved in the ribosome, nitrogen metabolism and oxidative phosphorylation pathways. Thirty‐one differentially expressed virulence genes (including genes involved in adhesion, degradation, host colonization and killing, and secondary metabolism) were found, suggesting that different molecular mechanisms were used by the fungus during the infection of different pests, which was further confirmed by disrupting creA and fkh2. Virulence assay results showed that ΔcreA and Δfkh2 strains of B. bassiana had distinct fold changes in their 50% lethal time (LT50) values (compared with the control stains) during infection of G. mellonella (ΔcreA: 1.38‐fold > Δfkh2: 1.18‐fold) and P. xylostella (ΔcreA: 1.44‐fold < Δfkh2: 2.25‐fold). creA was expressed at higher levels during the infection of G. mellonella compared with P. xylostella, whereas fkh2 showed the opposite expression pattern, demonstrating that creA and Fkh2 have different roles in B. bassiana during the infection of G. mellonella and P. xylostella. CONCLUSION: These findings demonstrate that B. bassiana regulates different genes to infect different insects, advancing knowledge of the molecular mechanisms of Beauveria–pest interactions. © 2018 Society of Chemical Industry Beauveria bassiana used different strategies to infect Galleria mellonella and Plutella xylostella by regulating of different genes. [ABSTRACT FROM AUTHOR]

MiRNAs in animals and plants play crucial roles in diverse developmental processes under both normal and stress conditions. miRNA-like small RNAs (milRNAs) identified in some fungi remain functionally uncharacterized. Here, we identified a number of milRNAs in Verticillium dahliae, a soil-borne fungal pathogen responsible for devastating wilt diseases in many crops. Accumulation of a V. dahliae milRNA1, named VdmilR1, was detected by RNA gel blotting. We show that the precursor gene VdMILR1 is transcribed by RNA polymerase II and is able to produce the mature VdmilR1, in a process independent of V. dahliae DCL (Dicer-like) and AGO (Argonaute) proteins. We found that an RNaseIII domain-containing protein, VdR3, is essential for V. dahliae and participates in VdmilR1 biogenesis. VdmilR1 targets a hypothetical protein-coding gene, VdHy1, at the 30UTR for transcriptional repression through increased histone H3K9 methylation of VdHy1. Pathogenicity analysis reveals that VdHy1 is essential for fungal virulence. Together with the time difference in the expression patterns of VdmilR1 and VdHy1 during fungal infection in cotton plants, our findings identify a novel milRNA, VdmilR1, in V. dahliae synthesized by a noncanonical pathway that plays a regulatory role in pathogenicity and uncover an epigenetic mechanism for VdmilR1 in regulating a virulence target gene. [ABSTRACT FROM AUTHOR]

Highlights • The first report on the epidemiological characteristics of H. parasuis isolated from Central Vietnam. • Serotype 5 was the most commonly, followed by serotypes 2, 4, 10, 9, 1, 6, 7 and 8. • The vta1 virulence gene was the most prevalence, followed by vta3 , vta2 , HPM-1371 , capD , HPM-1372 , lsgB and HPM-1373. • Strong correlations between some serotypes and virulence genes were observed. Abstract Haemophilus parasuis is a commensal Gram-negative bacterial pathogen in the upper respiratory tract of pigs, which causes Glässer's disease. More than 15 serotypes of H. parasuis have been identified with apparent differences in virulence. In this research, we surveyed the prevalence and distribution of serotypes and known virulence genes of the H. parasuis isolates collected from sick and healthy pigs in Quang Binh and Thua Thien Hue provinces in Central Vietnam. By using bacterial isolation and polymerase chain reaction (PCR), 56 out of 814 (6.9%) samples were positive for H. parasuis. The most prevalent serotypes were serotype 5 (15/56, 26.8%), followed by serotype 2 (13/56, 23.2%) and serotype 4 (10/56, 17.9%). The vta1 was the most frequently detected virulence gene which was present in 62.5% of the strains, followed by vta3 (42.9%), vta2 (39.3%), HPM-1371 (35.7%), capD (30.4%), HPM-1372 (12.5%), lsgB and HPM-1373 (both shared 8.9%). Strong correlations between some serotypes and known virulence genes were observed, in which virulence genes HPM-1371, HPM-1372, vta3, vta2 and capD were mainly clustered in serotypes 5/12, and vta2 clustered in serotype 2. This study presents the first baseline information on the epidemiological characteristics of H. parasuis isolates from Central Vietnam. [ABSTRACT FROM AUTHOR]

Purpose: The main objective of this study was to decipher the prevalence, antimicrobial resistance, major virulence genes and the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolated from different clinical sources in southern China. Materials and methods: The present study was performed on 187 non-duplicate S. aureus clinical isolates collected from three tertiary hospitals in Guangdong Province, China, 2010–2016. Antimicrobial susceptibility testing was performed by the disk diffusion method and by measuring the minimum inhibitory concentration. Screening for resistance and virulence genes was performed. Clonal relatedness was determined using various molecular typing methods such as multilocus sequence typing, spa and staphylococcal chromosomal cassette mec (SCCmec) typing. Whole genome sequencing was performed for three selected isolates. Results: Out of 187 isolates, 103 (55%) were identified as MRSA. The highest prevalence rate was found among the skin and soft tissue infection (SSTI) samples (58/103), followed by sputum samples (25/103), blood stream infection samples (15/103) and others (5/103). Antimicrobial susceptibility results revealed high resistance rates for erythromycin (64.1%), clindamycin (48.5%), gentamicin (36.9%) and ciprofloxacin (33.98%). All isolates were susceptible to vancomycin. Resistance genes and mutation detected were as follows: aac(6')-aph(2") (24.3%), dfrG (10.7%), rpoB (21.4%), cfr (0%), fexA (1.94%), gyrA (35.92%), gyrB (0.97%), grlA (20.4%), grlB (10.68%), ermA (21.4%), ermB (18.44%), ermC (21.4%) and lnuA (18.44%). Profiling of virulence genes revealed the following: sea (11.7%), seb (21.4%), sec (0.97%), sed (0.97%), hla (86.41%), hlb (17.48%), hlg (10.68%), hld (53.4%), Tsst-1 (3.9%) and pvl (27.2%). Clonal relatedness showed that ST239-SCCmecA III-t37 clone was the most prevalent clone. Conclusion: Our study elucidated the prevalence, antibiotic resistance, pathogenicity and molecular characteristics of MRSA isolated from various clinical sources in Guangdong, China. We found that the infectious rate of MRSA was higher among SSTI than other sources. The most predominant genotype was ST239-SCCmecA III-t37 clone, indicating that ST239-t30 clone which was previously predominant had been replaced by a new clone. [ABSTRACT FROM AUTHOR]

Abstract The expression of bacterial virulence factors is controlled in response to host or environmental factors and most virulence genes are not expressed under laboratory conditions. Investigations of molecular structures and cellular functions of bacterial virulence factors demand systems for experimentally controlled expression. We describe a simple and robust system that is based on the tetA promoter and the cognate repressor TetR. Expression under control of P tetA can be induced by non-antibiotic derivatives of tetracycline such as anhydrotetracycline (AHT). Tet-on expression cassettes can be used to replace native promoters of chromosomal genes or operons of interest. Tet-on plasmids allow episomal expression in homologous or heterologous host organisms. We demonstrate the application of Tet-on systems for the controlled induction of flagella assembly and motility, and for surface expression of adhesins of the chaperone/usher family of enteropathogenic Escherichia coli and autotransporter adhesins of Yersinia enterocolitica in Salmonella enterica and E. coli. Since inducer AHT can easily cross bacterial envelopes and mammalian cell membranes, the system can also be applied to control virulence genes in intracellular bacteria. We demonstrate the controlled synthesis, translocation and function of effector proteins of the type III secretion system of intracellular S. enterica. [ABSTRACT FROM AUTHOR]

Abstract Staphylococcus aureus can produce numerous surface proteins involved in the adhesion and internalization of host cells, immune evasion, and inflammation initiation. Among these surface proteins, the microbial surface components recognizing adhesive matrix molecules contain many crucial cell wall-anchored virulence factors. The Sar-family regulatory protein Rot has been reported to regulate many important extracellular virulence factors at the transcriptional level, including Spa and clumping factor B. SpoVG, a global regulator in S. aureus , is known to control the expression of numerous genes. Here, we demonstrate that SpoVG can positively regulate the transcription of rot by directly binding to its promoter. SpoVG can also positively regulate the transcription of spa and clfB through direct-binding to their promoters and in a Rot-mediated manner. Furthermore, SpoVG can positively modulate the human fibrinogen-binding ability of S. aureus. In addition, phosphorylation of SpoVG by the serine/threonine kinase, Stk1, can positively regulate its binding to the promoters of rot , spa , and clfB. The human cell infection assay showed that the adhesion and internalization abilities were reduced in the spoVG mutant strain in comparison to those in the wild-type strain. Collectively, our data reveal a SpoVG-Rot regulatory cascade and novel molecular mechanisms in the virulence control in S. aureus. [ABSTRACT FROM AUTHOR]

Highlights • Novel SCC mec type XII MRSA isolates were prevalent in the swine farms and slaughterhouse. • All SCC mec XII MRSA were multiresistant and carried MGEs (lsa(E) cluster and Tn 558). • All MRSA of SCC mec XII carried multiple virulence genes and clotted ruminant plasma. • PFGE showed cases of swine farm-to-slaughterhouse transmission of SCC mec XII MRSA. Abstract Methicillin-resistant Staphylococcus aureus (MRSA) has been a major public health concern. In this study, a total of 1485 samples from three swine farms, one slaughterhouse and one indoor market in Xiamen, China were collected in 2015, and the prevalence and profiles of MRSA were assessed. All the MRSA isolates were characterized by molecular typing, antibiotic susceptibility, coagulation activity, as well as PCR screening for 38 antibiotic resistance genes, two mobile genetic elements (lsa (E)-containing multiresistance gene cluster and Tn 558), and 36 virulence genes. During the study, 54 of 1485 (3.6%) samples from the swine production, processing and retail chain were found positive for MRSA. A relatively rare SCC mec XII genotype was prevalent in swine farm (84.6%, 11/13) and slaughterhouse isolates (80.6%, 25/31), but absent in the market isolates (0%, 0/10). Notably, all staphylococcal cassette chromosome mec (SCC mec) type XII MRSA isolates were resistant to at least 6 classes of antibiotics, carried two mobile genetic elements (lsa (E)-containing multiresistance gene cluster and Tn 558) and harbored multiple virulence genes. These multidrug resistant MRSA isolates could also coagulate both bovine and caprine plasma. Our results on the SCC mec XII MRSA isolates, particularly their profiles of related genotypes, antibiotic resistance and virulence determinants, illustrated the evolvement of livestock-associated (LA)-MRSA in the swine production environment and spread along the processing chain. The dominance of the SCC mec XII in MRSA isolates found in this study, differed from previous reports from China, indicated potential contribution associated with the production process. [ABSTRACT FROM AUTHOR]

Plant biotrophic oomycetes cause significant production problems and economic losses in modern agriculture and are controlled by fungicide applications and resistance breeding. However, high genetic variability and fast adaptation of the pathogens counteract these measures. As a consequence of the "arms race," new pathogen phenotypes recurrently occur and may rapidly dominate the population when selected through the pressure of control measures. Intensive monitoring with fast and reliable identification of virulence phenotypes is essential to avoid epidemics and the economic consequences in agriculture. For some of the most important downy mildews and white blister rusts, bioassay-based differentiation has been established to classify infectivity of field isolates or cultivated strains on hosts of defined resistance. However, the testing is laborious, time-consuming, logistically demanding, and prone to impreciseness. Alternatively, host independent classification could overcome these problems and enable fast assessment of the infection risk when monitoring the local pathogen population. The prerequisite would be the identification of pathogen characters correlating with the infection behavior. This review examines the current situation of bioassay-based pathotyping in six of the most important biotrophic oomycetes (Plasmopara viticola, Plasmopara halstedii, Pseudoperonospora cubensis, Peronospora tabacina, Bremia lactucae, and Albugo candida) and gives an overview on attempts and progress to identify genetic markers of the pathogens that correlate with their infection behavior. [ABSTRACT FROM AUTHOR]

Summary: Xanthomonas oryzae pv. oryzae is the causative agent of rice bacterial leaf blight. While the type III secretion system of X. oryzae pv. oryzae is essential for virulence, the biochemical activities and virulence mechanisms of non‐transcription activator‐like (non‐TAL) effectors delivered by this system are largely unknown. Here, by screening for non‐TAL effectors that contribute to X. oryzae pv. oryzae virulence, we revealed that Xanthomonas outer protein K (XopK) inhibits pathogen‐associated molecular pattern‐triggered immunity upstream of mitogen‐activated protein kinase cascades. Specifically, XopK interacted with and directly ubiquitinated rice somatic embryogenic receptor kinase 2 (OsSERK2), resulting in its degradation. Accordingly, mutation of a putative ubiquitin‐conjugation enzyme (E2) binding site abolished XopK‐induced degradation of OsSERK2 and compromised XopK‐dependent virulence. As crucial immune regulators associated with a multitude of immune receptors, SERKs have been shown to be perturbed by Pseudomonas effectors via different mechanisms. Our study revealed a distinct perturbation mechanism of SERK activity via ubiquitination achieved by Xanthomonas non‐TAL effector. [ABSTRACT FROM AUTHOR]

A virulent infectious bronchitis virus (IBV), designated as CK/CH/GD/QY16 (referred as QY16), was isolated from a diseased chicken farm in Guangdong province, China, in 2016. The complete genome of the strain was sequenced and analyzed. The results show that the genome of QY16 consists of 27,670 nucleotides, excluding poly (A) tail, and that its genome organization is 5' UTR-1a-1b-S-3a-3b-E-M-4b-4c-5a-5b-N-6b-3' UTR-poly (A) tail. Sequence comparison among QY16 and other IBV strains was conducted and its results demonstrate that the S1 gene of QY16 has the highest nucleotide sequence identity with that of 4/91, and the other part of its genome is highly similar to that of YX10. The results of the phylogenic analysis show that the entire genome of QY16 and most of the QY16 genes are located in the same cluster as those of YX10, except for the S1 gene which is located in the same cluster with that of 4/91. It has been further confirmed by the RDP and SimPlot analysis that QY16 is a recombinant strain deriving from YX10 (as the major parental sequence) and 4/91 (as the minor parental sequence), and that the recombination occurs in a region which includes the 3'-terminal 1b sequence (85 nt) and the 5'-terminal S1 protein gene sequence (1,466 nt). The results of the vaccination-challenge test suggest that QY16 is a nephropathogenic strain of IBV and that the vaccine strains–H120 and 4/91—cannot provide effective protection against it. These results indicate that the continuing evolution of IBV strains by genetic drift and genetic recombination may lead to IBV outbreaks even among the vaccinated chickens in China. [ABSTRACT FROM AUTHOR]

Goatpox virus (GTPV) is an important member of the Capripoxvirus genus of the Poxviridae. Capripoxviruses have large and complex DNA genomes encoding many unknown proteins that may contribute to virulence. We identified that the 135 open reading frame of GTPV is an early gene that encodes an ~18-kDa protein that is nonessential for viral replication in cells. This protein functioned as an inhibitor of nuclear factor-?B activation and apoptosis, and is similar to N1L protein of vaccinia virus. In the natural host, sheep, deletion of the 135 gene of GTPV live vaccine strain AV41 resulted in less attenuation than that induced by deletion of the tk gene; a well-defined nonessential gene in the poxvirus genome. Using the 135 gene as the insertion site, a recombinant AV41 expressing hemagglutinin of peste des petits ruminants virus (PPRV) was generated and elicited stronger neutralization antibody responses than that using the traditional tk gene. These results suggest that 135 gene of GTPV encodes an immunomodulatory protein to suppress host innate immunity, and may serve as an optimized insertion site to generate capripoxvirus-vectored live dual vaccines. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease virus (FMDV) has a wide host range. Its pathogenesis varies among hosts and types of viruses. Most investigations of pathogenesis have been performed on cattle and swine. However, FMDV research in cattle is hampered by the lack of a stable in vitro infection model. In this study, the stable bovine thyroid (BTY) cell line hTERT-BTY from primary BTY cells was established by telomerase reverse transcriptase over expression. The results of karyotype analysis and experiments on morphological and biological characteristics indicated that this cell line possessed the qualities of primary BTY cells, which could be extended indefinitely with stable morphology and steady growth rates. The hTERT-BTY cell line, has 60 chromosomes including 29 pairs of autosomes and 1 pair of sex chromosomes without structure aberrations. It can express thyroid-specific function genes thyroid-stimulating hormone receptor and sodium/iodide symporter in high abundance ratios. The cell line is sensitive to FMDV strains and is expected to be used as a powerful tool for FMDV clinical diagnosis, separation, detection and culture. Also, the different mRNA expression levels in infected and uninfected hTERT-BTY cells were analyzed in this study to identify the pathways of immunity using RNA-seq. The results suggested that the hTERT-BTY cell line could be regarded as an effective tool for the immune response exploration of FMDV. In conclusion, this study provided a useful tool for FMDV clinical diagnosis, separation, detection, and culture. The cell line also could serve as an in vitro model to study the mechanism underlying FMDV pathogenicity and host–virus interaction. [ABSTRACT FROM AUTHOR]

Pasteurella multocida is a gram-negative, non-motile bacterial pathogen, which is associated with chronic and acute infections as snuffles, pneumonia, atrophic rhinitis, fowl cholera and hemorrhagic septicemia. These diseases affect a wide range of domestic animals, leading to significant morbidity and mortality and causing significant economic losses worldwide. Due to the interest in deciphering the genetic diversity and process adaptive between P . multocida strains, this work aimed was to perform a pan-genome analysis to evidence horizontal gene transfer and positive selection among 23 P . multocida strains isolated from distinct diseases and hosts. The results revealed an open pan-genome containing 3585 genes and an accessory genome presenting 1200 genes. The phylogenomic analysis based on the presence/absence of genes and islands exhibit high levels of plasticity, which reflects a high intraspecific diversity and a possible adaptive mechanism responsible for the specific disease manifestation between the established groups (pneumonia, fowl cholera, hemorrhagic septicemia and snuffles). Additionally, we identified differences in accessory genes among groups, which are involved in sugar metabolism and transport systems, virulence-related genes and a high concentration of hypothetical proteins. However, there was no specific indispensable functional mechanism to decisively correlate the presence of genes and their adaptation to a specific host/disease. Also, positive selection was found only for two genes from sub-group hemorrhagic septicemia, serotype B. This comprehensive comparative genome analysis will provide new insights of horizontal gene transfers that play an essential role in the diversification and adaptation mechanism into P . multocida species to a specific disease. [ABSTRACT FROM AUTHOR]

Background Allelic variation of the virulence genes, vacA and cagA, as the most important virulence associated genes play an important role in the pathogenesis of severe gastrointestinal disease. Objective The aim of the present study was to identify the diversity of the virulence genes in patients with Gastric Cancer (GC), who were referred to the gastro-endoscopy unit of Imam Khomeini Hospital, Ahvaz Jundishapur University of medical science, Ahvaz, Iran. Methods Gastric biopsy specimens from 301 patients suspected to gastrointestinal disorders, were analyzed for H. pylori using molecular and phenotypical methods (culture, and biochemical test (catalase, oxidase and urease tests)). Results Among 201 PCR positive for H. pylori , using histopathological methods, 22 (10.9%) patients had GC. Presence of vacA gene in our H. pylori strains was 100% (201/201), while the most virulent vacA s1 allele was detected in 82.6% isolates, and the mid region vacA m1 was found in 39.8% isolates. The vacA s1/m1 genotype was the most virulent allelic combination in GC and Peptic Ulcer Disease (PUD) in 68.2% and 50%, respectively. The cagA gene was detected in 66.7% isolates. Among the cagA positive isolates, EPIYA-ABC motif was the most common motif in the GC (66.7%), PUD (55.6%) and Erosive Gastroduodenitis (EG) samples (55.2%), while EPIYA-ABCC was the most common motif (58.7%) in the Non-Ulcer Dyspepsia (NUD) samples. The vacA s1m1/ cagA + combination was detected in GC (73.3%) and PUD (51.9%), while vacA s1m2/ cagA + presented in the NUD and EG samples in 77.8% and 62.1%, respectively. Conclusion In this work, Western type (EPIYA-ABC and ABCC motifs) cagA , vacA s1m1 combinations have been demonstrated as the dominant genotype in the tested Ahvazian H. Pylori strains. Also the participation of cag A gene and vacA s1m1 genotype in development and severity of gastric disorder was well evident. Therefore, infection with H. pylori strain containing the cagA gene or the vacA s1m1 genotypes could be associated with increased risk of GC. This is the first study in our area that reports the high incidence and diversity of allelic combination of cagA and vacA genes in gastroduodenitis patients. [ABSTRACT FROM AUTHOR]

Incidental findings in genomic data have been studied in great detail in the recent years, especially from population-scale data sets. However, little is known about the frequency of such findings in ethnic groups, specifically the Middle East, which were not previously covered in global sequencing studies. The availability of whole exome and genome data sets for a highly consanguineous Arab population from Qatar motivated us to explore the incidental findings in this population-scale data. The sequence data of 1005 Qatari individuals were systematically analyzed for incidental genetic variants in the 59 genes suggested by the American College of Medical Genetics and Genomics. We identified four genetic variants which were pathogenic or likely pathogenic. These variants occurred in six individuals, suggesting a frequency of 0.59% in the population, much lesser than that previously reported from European and African populations. Our analysis identified a variant in RYR1 gene associated with Malignant Hyperthermia that has significantly higher frequency in the population compared to global frequencies. Evaluation of the allele frequencies of these variants suggested enrichment in sub-populations, especially in individuals of Sub-Saharan African ancestry. The present study thereby provides the information on pathogenicity and frequency, which could aid in genomic medicine. To the best of our knowledge, this is the first comprehensive analysis of incidental genetic findings in any Arab population and suggests ethnic differences in incidental findings. [ABSTRACT FROM AUTHOR]

Abstract: The Rio Bravo (Rio Grande) adjoins various states in the Mexican region and has a great importance in water distribution in the northeast Tamaulipas (Mexico). In this work 161 strains were isolated, identified and characterized from the water samples taken from the flow of the Rio Bravo and the two inner canals that cover Reynosa city. The strains were identified as Vibrio cholerae (74·5%), Vibrio spp. (1·2%) and Vibrio mimicus (0·6%). Furthermore, the detected virulence genes in the V. cholerae strains, were the hlyA, ompU, tcpA, toxR genes in 78·3, 62·5, 15·8 and 90·8% respectively. Only the ompU and vmh genes were detected in the V. mimicus strain. These results indicate the presence of multi‐toxigenic V. cholerae strains in the Rio Bravo/Grande and in the water bodies from Reynosa city, which could represent a risk for the exposed population. Significance and Impact of the Study: Water quality is associated with public health, as it plays an important role in the transmission and epidemiology of pathogens such as Vibrio, since this species have been responsible for human diseases around the world. This study demonstrated the presence of toxigenic Vibrio species in water bodies in Reynosa surroundings, indicating that water bodies may be a source of public health risk. [ABSTRACT FROM AUTHOR]

Standardized protocols for determining pathogenicity of Fusarium oxysporum ff. spp. canariensis and palmarum, the cause of Fusarium wilt of ornamental palms, were developed using small palm plants with a minimum of three to four seedling leaves. For both protocols, a standard amount of inoculum (25 ml of 106 spores/ml) was pipetted onto and between the leaf bases of each plant, with excess material running down onto the roots and collecting in the container. After 3 days, the palm plants were transplanted into 450-ml containers filled with pine bark/sedge peat/sand potting mix. The protocol for F. oxysporum f. sp. canariensis differed from the protocol of F. oxysporum f. sp. palmarum by requiring that the lower 20% of roots be cut prior to inoculation and having the assay run for 6 months versus 3 months. These two assays were used to evaluate pathogenicity of multiple isolates of each pathogen. All 15 isolates of F. oxysporum f. sp. palmarum were pathogenic, whereas only 7 of 13 F. oxysporum f. sp. canariensis isolates were pathogenic. These assays were also used to determine susceptibility of other palm species to these pathogens. Washingtonia filifera, Butia odorata, Phoenix dactylifera, and P. reclinata appeared susceptible to F. oxysporum f. sp. palmarum, at least in the seedling stage. Other inoculation techniques are described that may be useful for evaluating Fusarium wilt disease management methods. [ABSTRACT FROM AUTHOR]

Campylobacter jejuni is the causal agent of the food-borne infection with the highest incidence in Europe. Both poultry and wild birds are a major reservoir. To gain insight into the population structure, virulence potential, and antimicrobial resistance (AMR), a collection of 150 isolates from three different ecological niches (broilers, wild birds, and human patients) was studied. Despite the high genetic diversity found, the population structure defined two distinct clusters, one formed mostly by broiler and human isolates and another one by most wild bird isolates. The ST-21 complex exhibits highest prevalence (in humans and broilers), followed by ST-1275 complex (only in wild birds). The ST-48, -45, and -354 complexes were found in all three niches, but represent only 22 out of 150 studied strains. A higher occurrence of AMR and multidrug resistance was detected among broiler and human isolates. Moreover, significant differences were found in the distribution of certain putative virulence genes. Remarkably, many wild bird strains were negative for either cdtA, cdtB , or cdtC from the canonical strain 81-176, whereas all broiler and human strains were positive. These data suggest that the different variants of the cdt genes might be relevant for the efficient colonization of certain hosts by C. jejuni. Our study contributes to the understanding of the role of the diverse Campylobacter reservoirs in the transmission of campylobacteriosis to humans. [ABSTRACT FROM AUTHOR]

Some pathogens and pests deliver small RNAs (sRNAs) into host cells to suppress host immunity. Conversely, hosts also transfer sRNAs into pathogens and pests to inhibit their virulence. Although sRNA trafficking has been observed in a wide variety of interactions, how sRNAs are transferred, especially from hosts to pathogens and pests, is still unknown. Here, we show that host Arabidopsis cells secrete exosome-like extracellular vesicles to deliver sRNAs into fungal pathogen Botrytis cinerea. These sRNA-containing vesicles accumulate at the infection sites and are taken up by the fungal cells. Transferred host sRNAs induce silencing of fungal genes critical for pathogenicity. Thus, Arabidopsis has adapted exosome-mediated cross-kingdom RNA interference as part of its immune responses during the evolutionary arms race with the pathogen. [ABSTRACT FROM AUTHOR]

Objective Determine if there is a link between virulenceassociated genes of Haemophilus parasuis and the genotype and serovar of isolates. Methods Isolates of H. parasuis from 38 farms across six Australian states, representing all serovars present in Australia, were assessed for the presence of virulence-associated genes (vtaA, hhdBA, fhuA, lsgB and capD). Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR) and multilocus sequence typing (MLST), together with existing knowledge of the serovar of the isolates and the health status of the source pig, were used to examine 75 Australian isolates of H. parasuis. Results An analysis of the ERIC-PRC patterns revealed six main clusters. One cluster of 25 isolates lacked virulence-associated genes and on the basis of serovar and field data, appeared to be mostly non-pathogenic. Another cluster of five isolates containing most of the virulence-associated genes appeared to be pathogenic based on the field and serovar data. The remaining four clusters were a mix of apparently pathogenic and apparently non-pathogenic isolates. The MLST results revealed a high degree of variation, with 54 sequence types of which 41 had not been previously recognised. Conclusion Not all virulence-associated genes are present in potentially pathogenic strains of H. parasuis. Australian isolates of H. parasuis are both genetically diverse and markedly different from isolates in other countries. These key findings suggest that vaccine development will be challenging. [ABSTRACT FROM AUTHOR]

Black fungi comprise a diverse group of melanized microorganisms, many of which are able to infect humans. One of the recognized diseases that arise with black fungi infection is chromoblastomycosis, a neglected implantation mycosis. Considering their ecology, black fungi may face conditions with distinct metal availability. Zinc and copper are essential transition metals, which become toxic in excess. During the interaction with host, fungi may face either metal deprivation or poisoning. Here we report an in silico analysis of four black fungi genomes concerning zinc and copper homeostasis. Overall, these organisms share apparatus of metal uptake, storage and detoxification with other pathogenic and non-pathogenic fungi. Genes coding plasma membrane and organelle transporters, as well as metal binding proteins were identified. Althought putatives zinc and copper responsive transcription factors have been found in the analyzed genomes, remarkable structural differences were perceived when compared to the already characterized regulators. Black fungi may harbor unique features concerning the regulation of zinc and copper homeostasis, which is probably a result of the niches they can inhabit. The data provided here add knowlegde to a still unexplored aspect of black fungi biology that may be useful in the understanding of their pathogenicity. [ABSTRACT FROM AUTHOR]

In the African meningitis belt, a region of sub-Saharan Africa comprising 22 countries from Senegal in the west to Ethiopia in the east, large epidemics of serogroup A meningococcal meningitis have occurred periodically. After gradual introduction from 2010 of mass vaccination with a monovalent meningococcal A conjugate vaccine, serogroup A epidemics have been eliminated. Starting in 2013, the northwestern part of Nigeria has been affected by yearly outbreaks of meningitis caused by a novel strain of serogroup C Neisseria meningitidis (NmC). In 2015, the strain spread to the neighboring country Niger, where it caused a severe epidemic. Following a relative calm in 2016, the largest ever recorded epidemic of NmC broke out in Nigeria in 2017. Here, we describe the recent evolution of this new outbreak strain and show how the acquisition of capsule genes and virulence factors by a strain previously circulating asymptomatically in the African population led to the emergence of a virulent pathogen. This study illustrates the power of long-read whole-genome sequencing, combined with Illumina sequencing, for high-resolution epidemiological investigations. [ABSTRACT FROM AUTHOR]

Valsa mali, a parasitic fungus, is a destructive pathogen of apple tree that causes heavy economic losses in China. The pathogen secretes various cell wall-degrading enzymes (CWDEs) that degrade plant cell-wall components, and thus facilitate its entry into host cells. Therefore, functional analysis of the genes encoding CWDEs is necessary to understand virulence of V. mali toward apple tree. Here, we identified and cloned an endo-β-1,4-xylanase gene, VmXyl1 in V. mali. The full-length cDNA of VmXyl1 is 1626 bp containing 50- and 30-non-coding regions, as well an open reading frame of 1320 bp that encodes a protein with a calculated molecular mass and an isoelectric point of 43.8 kDa and 4.4, respectively. The predicted amino acid sequences showed significant homology to a family GH10 of glycosyl hydrolases. The apple branch extract and beechwood xylan, but not glucose, induced the expression of VmXyl1. Furthermore, VmXyl1 had high expression levels in the apple tree bark during the pathogen infection. The deletion of VmXyl1 did not affect mycelia growth; however, it significantly reduced pycnidia formation in V. mali. The deletion strains showed a reduced virulence toward apple leaves and twigs. Moreover, the mutant strains had reduced endo-β-1,4-xylanase activity and growth when cultured using beechwood xylan as the only carbon source. Reintroducing wild-type VmXyl1 into the mutant strains rescued the defect phenotype. We conclude that VmXyl1 determines the virulence of V. mali toward apple tree. These results provide valuable insight into the plant-pathogen molecular interactions. [ABSTRACT FROM AUTHOR]

We investigated the involvement of two avirulence genes, avrA ( ripAA in unified nomenclature) and popP1 ( ripP1 in unified nomenclature), of Japanese Ralstonia solanacearum strains in the pathogenicity to tobacco. One virulent strain OE1-1 and four hypersensitive response (HR)-eliciting strains, 8107, MAFF 211471, MAFF 211496, and MAFF 301520, were used. While 8107 and MAFF 211471 contain popP1 , other three strains do not. When popP1 of strain 8107 was transferred into the virulent strain OE1-1, the transconjugant strain had significantly reduced virulence but did not become a HR-eliciting strain. We deleted avrA and/or popP1 from the HR-eliciting strains; all deletion mutants still elicited a HR and did not become virulent to tobacco, although leaf lesion appearance was delayed on infection with avrA mutants. These results indicate that although avrA and popP1 could be functional as avirulence determinants, other unidentified factors are necessary for full virulence or HR elicitation by Japanese R. solanacearum strains. [ABSTRACT FROM AUTHOR]

Since 2015, an emerging infectious disease of inclusion body hepatitis and hydropericardium syndrome (IBH-HPS) has been occurred in China, which caused economic loss in poultry farming. In this study, we isolated four fowl adenovirus strains from flocks with an outbreak of HPS. The complete nucleotide sequence of SC-Neijiang was determined and its pathogenicity was evaluated. Phylogenetic analysis based on hexon gene revealed that all the isolates belonged to fowl adenovirus serotype 4. The full genome sequence of SC-Neijiang has a size of 43,719 bp, with 54.85% G + C content. Compared with JSJ13, 11-amino-acid deletion at the ORF29 was appeared on SC-Neijiang. In infectious experiments, 80% (16/20) birds died in intramuscular route and lesions characteristic for Hydropericardium Syndrome (HPS), while 5% (1/20) birds died in nasal route. The viral DNA was further detected by real-time PCR in several chicken organs. The highest titers were recorded in all the organs at day 5 post-infection. To our knowledge, this is first report on the prevalence of fowl adenovirus in Southwest China. This research elucidated the characteristics of genome sequence and pathogenicity of Chinese FAdV-4 strain and provided theoretical support for the prevention and control of the disease. [ABSTRACT FROM AUTHOR]

Fifty-one blood samples were collected from four fields in the north of Baghdad at 23-28th of December 2013 from animals suffered from abortion cases or had specific illness signs, twenty-seven isolates including five Brucella species were determined, B. abortus (37.04%), B. melitensis (29.64%), B. canis (14.81%), B. ovis (11.11%) and B. suis (7.4%), which is recorded in the first time in Iraq. The result shows that all bacterial isolates were sensitive to both gentamycin and kanamycin (100%), as well a good activity to meropenem against the isolated bacteria (96.3%), also it shows that the sensitivity of rifampicin, tetracycline and streptomycin were (85.2%), (77.7%) and (62.9%) respectively, while the activity of ampicillin was less than others and the results recorded (55.5%). The results showed that only eleven isolates (40.7 % ) contain one plasmid or more while the other sixteen isolates (59.3 % ) were free plasmid bacteria. All four studied virulence gens were recognized in the brucella isolates in different ratio, and the genes percentages were vary in all Brucella species. Generally, the most common gene was ure gene which presences forty-two times (88.9%), while emrD gene recorded as the lowest percentage among all studied genes by its presence in eight isolates (29.6%), in addition, some genes were presence in all isolates such as znu A gene in B. abortus (100%) while other didn't recorded such as emrD gene in B. ovis (0%). [ABSTRACT FROM AUTHOR]

Oncolytic viruses gain cancer specificity in several ways. Like the majority of viruses, they grow better in cancer cells that are defective in mounting the host response to viruses. Often, they are attenuated by deletion or mutation of virulence genes that counteract the host response or are naturally occurring oncolytic mutants. In contrast, retargeted viruses are not attenuated or deleted; their cancer specificity rests on a modified, specific tropism for cancer receptors. For herpes simplex virus (HSV)-based oncolytics, the detargeting-retargeting strategies employed so far were based on genetic modifications of gD. Recently, we showed that even gH or gB can serve as retargeting tools. To enable the growth of retargeted HSVs in cells that can be used for clinical-grade virus production, a double-retargeting strategy has been developed. Here we show that several sites in the N terminus of gB are suitable to harbor the 20-amino-acid (aa)-long GCN4 peptide, which readdresses HSV tropism to Vero cells expressing the artificial GCN4 receptor and thus enables virus cultivation in the producer noncancer Vero-GCN4R cell line. The gB modifications can be combined with a minimal detargeting modification in gD, consisting in the deletion of two residues, aa 30 and 38, and replacement of aa 38 with the scFv to human epidermal growth factor receptor 2 (HER2), for retargeting to the cancer receptor. The panel of recombinants was analyzed comparatively in terms of virus growth, cell-to-cell spread, cytotoxicity, and in vivo antitumor efficacy to define the best double-retargeting strategy. [ABSTRACT FROM AUTHOR]

Probiotics, prebiotics, or a combination of these two referred to as synbiotics, have emerged as a promising natural and alternative approach to make the sustainable animal farming. Previously, we reported that in the presence of prebiotic like components such as peanut flour, Lactobacillus produced more metabolites and inhibited several enteric pathogens. In this study, we tested a genetically modified lactic acid-producing bacterial strain Lactobacillus casei (LC), that produced large amounts of bioactive compounds including conjugated linoleic acid (CLA), in inhibiting enteric bacterial pathogens and improving host immune systems. The genetically engineered LC strain, LC + mcra (overexpressed mcra gene in LC) effectively eliminated Campylobacter jejuni (CJ) in co-culture condition without any stimulation with prebiotic like components. LC + mcra alone inhibited the growth of CJ completely by 48 h (P < 0.05) similarly the combine effect of LC with prebiotic like component, peanut flour. Cell free culture supernatants (CFCSs) of LC + mcra was also effective in growth reduction of CJ most efficiently (p < 0.05), followed by CFCSs of LC with peanut flour (p < 0.05). In co-culture conditions, LC with peanut flour, LC + mcra and their CFCSs reduced the adherence and invasion ability of CJ to both HD-11 and HeLa cells. Physicochemical properties and gene expressions related to CJ virulence were also altered by CFCSs treatments significantly. These findings suggest, LC + mcra can be an alternative in controlling CJ infection along with other beneficial attributes of LC. [ABSTRACT FROM AUTHOR]

Streptococcus dysgalactiae subspecies equisimilis (SDSE) is an emerging pathogen in animals and humans. Herein, we describe two clinical swine cases of SDSE infection presenting with lameness, neurological signs, or sudden death. Pathological examination indicated suppurative arthritis, encephalitis, and multifocal abscesses in kidney and heart. The ß-hemolytic colonies obtained from joint samples of each case were identified as SDSE. The two isolates had low minimum inhibitory concentrations for ß-lactams, and they presented the same virulence gene profile (slo-/sagA+/pSTKP8+). Molecular analysis by multilocus sequence typing identified the SDSE isolates from cases 1 and 2 as sequence types 315 and 252, respectively. [ABSTRACT FROM AUTHOR]

Karnal bunt of wheat (Tilletia indica) is an important internationally quarantined disease from food security point of view. For understanding host specificity and host-pathogen interaction, putative pathogenicity-related genes were analysed in Tilletia indica in response to host factor at different time points. Highest radial mycelia growth (3.4 cm) was recorded in media amended with susceptible host factor followed by resistant host (2.6 cm) and control (2.0 cm) at 30 days after incubation significantly. Fourteen homologous sequences of putative pathogenicity-related genes, viz. TiPmk1, TiKss1, TiHog1, TiHsp70, TiKpp2, TiCts1, TiHos2, TiChs1, TiPrf1, TiSid1, TiSsp1, TiSte20, TiUbc4 and TiUkc1, were identified in T. indica by in silico analysis. Some of the pathogenicity-related genes were highly expressed significantly in T. indica in response to susceptible host factor as compared to resistant host factor. TiPmk1, TiHog1, TiKss1 were found highly upregulated up to 26-fold (3 days), 20-fold (3 days) and 18-fold (4 days), respectively, significantly in presence of susceptible host factor. The TiCts1 and TiChs1 showed transcripts up to 26-fold (4 days) and 20-fold (3 days) in the presence of susceptible host factor. Further, the TiUbc4 and TiUkc1 were found upregulated up to 20-fold and 7-fold at 8 days and 3 days post incubation. This study provided the insight on expression of putative pathogenicity-related genes in T. indica which will help in understanding the infection mechanism and basis for further functional genomics approach. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae bacteremia biofilm traits and distribution characteristics have not been clarified. This study aimed to determine the prevalence and characteristics of K. pneumoniae bacteremia biofilm formation (BF) and to explore the virulence factors associated with K. pneumoniae BF. A total of 250 K. pneumoniae bacteremia isolates were collected from patients in Shenzhen and Shanghai, China. Virulence genes in their genomes were detected by PCR. The isolates were subjected to multilocus sequence typing (MLST) and clonal complex (CC) classification based on housekeeping genes. Biofilms were detected by crystal violet staining. Greater BF was observed in isolates from young adults (<40 years old) than in those fromseniors (≥65 years old; P = 0.002).MLST yielded 65 different sequence types (STs), with the most represented STs being ST11, ST23, and ST65, and the main CCs were CC23 and CC65; CC23 isolates exhibited greater BF than CC65 or ST11 isolates (both P < 0.001). BF was more pronounced among magA(K1), aero+, rmpA+, rmpA2+, allS+, wcaG+, and iutA+ isolates than in isolates that were negative for these virulence factors. Multivariate regression analysis revealed only wcaG as an independent risk factor for BF (odds ratio 11.426, P < 0.001), and BF was decreased when wcaG was silenced by antisense RNA. In conclusion, BF in K. pneumoniae bacteremia isolates was found to be associated with CC23 classification and the presence of the wcaG virulence factor gene. [ABSTRACT FROM AUTHOR]

Puccinia striiformis f.sp. tritici (Pst) is the causal agent of stripe (yellow) rust on wheat. It seriously threatens wheat production worldwide. The obligate biotrophic fungus is highly capable of producing new virulent races that can overcome resistance. Studying the inheritance of Pst virulence using the classical genetic approach was not possible until the recent discovery of its sexual stage on barberry plants. In the present study, 127 progeny isolates were obtained by selfing a representative Chinese Yellow Rust (CYR) race, CYR32, on Berberis aggregate. The parental isolate and progeny isolates were characterized by testing them on 25 wheat lines with different Yr genes for resistance and 10 simple sequence repeat (SSR) markers. The 127 progeny isolates were classified into 27 virulence phenotypes (VPs), and 65 multi-locus genotypes (MLGs). All progeny isolates and the parental isolate were avirulent to Yr5, Yr8, Yr10, Yr15, Yr24, Yr26, Yr32, and YrTr1; but virulent to Yr1, Yr2, Yr3, Yr4, Yr25, Yr44, and Yr76. The VPs of the parental isolate to nine Yr genes (Yr6, Yr7, Yr9, Yr17, Yr27, Yr28, Yr43, YrA, and YrExp2) and the avirulence phenotype to YrSP were found to be heterozygous. Based on the segregation of the virulence/avirulence phenotypes, we found that the VPs to Yr7, Yr28, Yr43, and YrExp2 were controlled by a dominant gene; those to Yr6, Yr9, and YrA (Yr73, Yr74) by two dominant genes; those to Yr17 and Yr27 by one dominant and one recessive gene; and the avirulence phenotype to YrSP by two complementary dominant genes. Molecular mapping revealed the linkage of 10 virulence/avirulence genes. Comparison of the inheritance modes of the virulence/avirulence genes in this study with previous studies indicated complex interactions between virulence genes in the pathogen and resistance genes in wheat lines. The results are useful for understanding the plant-pathogen interactions and developing wheat cultivars with effective and durable resistance. [ABSTRACT FROM AUTHOR]

Multidrug resistant Pseudomonas aeruginosa has frequently been reported as the cause of nosocomial outbreaks of burn wound infections. The pathogenesis of P. aeruginosa is partly due to the production of several cell-associated and extracellular virulence factors. A total of 93 P. aeruginosa isolated from burn wound infections were investigated for antimicrobial susceptibility and distribution of virulence genes. All (100%) isolates were resistant to one or more antimicrobial agents. The most frequent resistance found against ampicillin (91.4%), co-trimoxazole (77.4%), gentamicin (68.8%), cefotaxime (50.5%), aztreonam and piperacillin (41.9%). A total of 88 (94.6%) isolates were resistant to at least three different classes of antimicrobial agents and considered as multidrug resistance MDR. All isolates carried at least two or more different virulence genes. The most prevalent virulence gene was toxA (97.8%), followed by plcH (96.7%), phzI (96.7%), exoY (93.1%) and phzII (90.3%). exoU was not detected in P. aeruginosa isolates. The frequency of pilB (17.2%), exoT (20.4%), pilA (24.7%) and phzS/phzH (27.9%) was lower than other virulence genes. Twenty nine (31.2%) isolates had simultaneously 8 virulence genes, 22 (23.7%) isolates had 6 virulence genes and 19 (20.4%) isolates had 7 virulence genes. All MDR isolates carried at least 5 virulence factors. These results indicate a high frequency and heterogeneity of virulence gene profiles among multidrug resistant P. aeruginosa isolates recovered from burn wound infections. Therefore, appropriate surveillance and control measures are essential to prevent the further spread of these isolates in hospitals. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the prevalence of virulence genes responsible for the adhesion ( flaA , cadF and racR ) and invasion ( virB11 , iam and pldA ) in Campylobacter isolates from cattle and swine and determine their adherence and invasion abilities. The studies conducted revealed high prevalence rate of adherence and invasion associated genes irrespective of the isolates origin. All Campylobacter strains of swine and cattle origin adhered to HeLa cells at mean level 0.1099% ± SD 0.1341% and 0.0845% ± SD 0.1304% of starting viable inoculum, respectively. However swine isolates exhibited higher invasion abilities (0.0012% ± SD 0.0011%) compared to bovine isolates (0.00038% ± SD 0.00055%). The results obtained revealed significantly positive correlation between invasion and adherence abilities of swine origin isolates (R = 0.4867 in regard to C. jejuni and R = 0.4507 in regard to C. coli ) and bovine origin isolates (R = 0.726 in regard to C. jejuni ). Bacterial virulence is multifactorial and it is affected by the expression of virulence genes. Moreover the presence of virulence genes determines the ability of Campylobacter isolates to adhere and invade the cells. [ABSTRACT FROM AUTHOR]

Objectives: The criteria for identification of Enterococcus faecium (Efm) with the ability to cause human infections are currently being debated by the European Food Safety Authority (EFSA). Strains that have an MIC of ampicillin of ≤ 2 mg/L and lack IS16/esp/hyl genes should be regarded as safe for use as feed additives in animal nutrition, despite the lack of knowledge about putative virulence marker (PVM) distribution in community Efm. We analysed the distribution of major PVM and ampicillin phenotypes in large Efm collections to investigate further the safety of strains from a public health perspective.Methods: Thirty-three PVM were assessed by PCR/sequencing among clonally disparate Efm (n = 328; 1986-2015) from different origins. We analysed ampicillin susceptibility (Etest/broth microdilution) according to EUCAST guidelines, clonal relationship (MLST) and genomic location of PVM (S1-PFGE/hybridization).Results: Infection-derived Efm were more enriched in PVM and the increase in ampicillin MIC was positively correlated with an enrichment in different PVM. PVM coding for surface (esp/sgrA/ecbA/complete acm) and pili proteins, or others enhancing colonization (hyl/ptsD/orf1481) or plasticity (IS16), were strongly associated with clinical Efm (mostly clade A1), but also observed in clades A2/B at different rates. ptsD was a good marker of ampicillin-resistant Efm. ptsD, IS16, orf1481, sgrA and hospital variants of complete pili gene clusters are proposed as markers to assess the safety of Efm strains.Conclusions: Our study expands on the distribution of PVM in diverse Efm lineages and demonstrates the enrichment in infection-derived strains of PVM not previously included in EFSA's list of Efm safety criteria. The evidence of relevant Efm infection markers can impact the risk assessment of Efm strains in different public health contexts. [ABSTRACT FROM AUTHOR]

Cucumber mosaic virus (CMV), a positive-sense single-stranded RNA virus, has a very wide host range and a worldwide distribution, and is considered as one of the most virulent plant viruses in the world. The CMV gene sequences, gene products, and their interaction with hosts have been extensively reported since it was discovered in 1916. With the development of high-throughput sequencing and proteomics, great progress has been made in the molecular mechanism of CMV pathogenesis in recent years. In this review, we introduce CMV-encoded proteins, CMV-related satellite RNAs and the roles of host factors in the pathogenesis of CMV, to provide a theoretical basis for future study of CMV. [ABSTRACT FROM AUTHOR]

Background: Severe infections with highly virulent community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are a global problem. However, the molecular events defining the evolution of CA-MRSA are still poorly understood. MRSA of sequence type (ST) 398 is known to frequently infect livestock, while ST398 isolates infecting humans are commonly methicillin-susceptible or represent MRSA originating from livestock-associated (LA)-MRSA. Methods: We used whole genome sequencing of newly detected CA-MRSA ST398 isolates, in comparison to geographically matched LA-MRSA and methicillin-sensitive ST398, to determine their evolutionary history. Furthermore, we used phenotypic analyses including animal infection models to gain insight into the evolution of virulence in these CA-MRSA isolates. Finally, we determined methicillin resistance and expression of the methicillin resistance-conferring gene mecA and its penicillin-binding protein product, PBP2a, in a large series of CA-MRSA strains of divergent STs. Results: We report several cases of severe and fatal infections due to ST398 CA-MRSA. The responsible isolates showed the typical genetic characteristics reported for human-adapted methicillin-sensitive ST398. Whole genome sequencing demonstrated that they evolved from human-adapted, methicillin-susceptible clones on several different occasions. Importantly, the isolates had not undergone consistent genetic alterations or changes in virulence as compared to their methicillin-susceptible predecessors. Finally, we observed dramatically and consistently lower methicillin resistance and expression of the resistance gene mecA, as compared to hospital-associated MRSA strains, in a diverse selection of CA-MRSA strains. Conclusions: Our study presents evidence for the development of highly virulent human-adapted ST398 CA-MRSA isolates from methicillin-susceptible predecessors. Notably, our investigation indicates that, in contrast to widespread notions, the development of CA-MRSA is not necessarily associated with the acquisition of specific virulence genes or other virulence-increasing changes. Rather, our findings emphasize the importance of the CA-MRSA-characteristic staphylococcal cassette chromosome mec types, which provide only low-level methicillin resistance, for that process. Our findings are of particular importance for the diagnosis of CA-MRSA, inasmuch as they indicate that the presence of specific virulence genes cannot generally be used for that purpose. [ABSTRACT FROM AUTHOR]

Enterovirus 71 (EV71) can cause hand, foot, and mouth disease in children, and severe infections can induce neurological complications and even death. However, the pathogenesis of EV71 remains unknown. The 2A proteinase (2A pro ) of EV71 plays an important role in segmenting the precursor polyprotein during viral replication, inhibiting host protein synthesis, and evading innate immunity. This study was to determine the function of EV71 2A pro in replication and virulence. A chimeric strain (SDLY 107-2A-1) was recombined by replacing 2A pro of a severe strain (SDLY107) with that of a mild strain (SDLY1) based on an infectious cDNA clone. The replication kinetics of the chimeric strain in vitro and in vivo were determined by qRT-PCR, which showed that the chimeric strain replicated slower and generated less viral RNA than the severe strain. The pathological change and viral load of chimeric strain infected mice were intermediate between severe strain infected mice and mild strain infected mice. Cellular cytotoxicity assays revealed that 2A pro was associated with the neurotoxicity of EV71. Histopathological and immunohistochemical assays detected tissue pathological damage in the lungs, muscles, brain, and intestinal tissues. Together, these results suggest that 2A pro modulates replication and virulence of EV71. This provides a theoretical basis for virulence determination of EV71. [ABSTRACT FROM AUTHOR]

An increasing number of studies are suggesting that plant viruses, including southern rice black-streaked dwarf virus (SRBSDV), can adversely affect biological characteristics of insect vectors by unknown mechanisms. To study the adverse effect of SRBSDV at cellular level on the insect vector, we promoted viral infection by the disruption of the small interfering RNA (siRNA) pathway. The transmission electron microscopy was utilized to describe the ultrastructural changes that occurred in insects when the core component of the siRNA pathway, Dicer-2, was knocked down. The increasing accumulation of SRBSDV in virus-infected vector, the white-backed planthoppers, caused severe cytopathology in the alimentary canal. Similar cytopathology changes in the midgut ultrastructure were characterized in the virus-infected incompetent vector, the small brown planthopper. These results not only add support to the existing evidence suggesting that the siRNA pathway has an antiviral effect, but also reveal the universal and potential ability of SRBSDV to cause damage to the insect tissues of both the vector and non-vector. [ABSTRACT FROM AUTHOR]

Bovine mastitis is still a central problem on dairy farms despite control programs, and Escherichia coli is a crucial pathogen during the development of bovine mastitis. The virulence genes, antimicrobial susceptibility, and mortality of mice infected with different E. coli isolates from bovine mastitis were determined in this study. According to the presence of the specific genes chuA, yjaA, and TspE4.C2, these isolates mainly belonged to 2 different groups: group A (47/79) and group B1 (22/79). The ompC gene was detected in all the isolates, followed by fimH (89.9%), ECs3703 (88.6%), and ompF (73.4%), whereas most of the virulence genes were not detected in these isolates. The results of the antimicrobial susceptibility tests indicated that the isolates were susceptible to the fluoroquinolones and aminoglycosides. An inverse relationship was shown between the expression level of ompF and antimicrobial resistance; additionally, the isolates that were nonsusceptible to at least 4 classes of antimicrobial agents showed a lower mortality to mice in comparison with the susceptible isolates. This study indicated that antibiotic resistance had emerged in E. coli from bovine mastitis in this area, and appropriate measures should be taken to avoid potential threats to humans and other animals. [ABSTRACT FROM AUTHOR]

Legionella pneumophila, the causative agent of Legionnaires' disease, is widely distributed throughout natural and artificial water systems and can replicate in macrophages and amoebae. Amoebae are the natural hosts of L. pneumophila, whereas macrophages are incidentally infected. The life cycle of L. pneumophila comprises a replicative phase within the Legionella-containing vacuole (LCV) and a transmissive phase during which bacterial cells become motile and are released via killing of the host. Although the host death mechanisms induced by L. pneumophila have been studied, the expression patterns of related L. pneumophila genes have not been reported. The present study compared the expression patterns of host cell death-associated genes in L. pneumophila grown in the human monocytic cell line THP-1 and Acanthamoeba castellanii. Notably, when L. pneumophila was grown in THP-1, expression of the gene flaA, which is involved in the induction of pyroptosis, was downregulated during the course of infection. In contrast, sdhA associated indirectly with host death, was upregulated. Expression of the genes vipD and sidF, which are involved in the induction and suppression of apoptosis, changed by less than 2-fold. Notably, a lower percentage of pyroptotic cells was observed among infected THP-1 cells relative to uninfected cells, and the latter exhibited stronger expression of caspase-1. A different pattern was observed when L. pneumophila was grown in A. castellanii: flaA and vipD were activated, whereas sdhA and sidF were downregulated during the later stage of replication. The percentage of non-viable (annexin-V+ PI+ or annexin-V+PI−) A. castellanii organisms increased with Legionella infection, and the expression of metacaspase-1, which is involved in encystation was up-regulated at late infection time. In summary, L. pneumophila can multiply intracellularly in both amoebae and macrophages to induce cell death and secondary infection, and this characteristic is essential for its survival in water and the lungs. The gene expression profiles observed in this study indicated the increased cytotoxicity of L. pneumophila in A. castellanii, suggesting an increased adaptation of Legionella to this host. [ABSTRACT FROM AUTHOR]

The current study was aimed to investigate the prevalence of ureC, rsbA, zapA and mrpA virulence genes using polymerase chain reaction (PCR) in Proteus spp. isolated from 5 commercially popular species of pet turtles and comparison of the mrpA gene sequences of Proteus mirabilis isolates with human clinical isolates. A total of 24 isolates in pet turtles were identified, comprised of P. mirabilis (15), Proteus vulgaris (7) and Proteus hauseri (2). The prevalence of ureC, rsbA, zapA and mrpA genes among all identified Proteus spp. isolates were 91.7%, 50%, 45.8% and 45.8%, respectively. The average percentage similarities of mrpA gene sequence of pet turtle P. mirabilis isolates to human urinary and respiratory isolates were 96.35% and 94.85%, respectively. The prevalence of virulence genes and high similarity of mrpA gene sequences between pet turtles and human P. mirabilis isolates revealed that though pet turtles are healthy, these animals may pose a potential risk of urinary and respiratory infections to humans. [ABSTRACT FROM AUTHOR]

To counteract host antiviral RNA silencing, plant viruses express suppressor proteins that function as pathogenicity enhancers. The genome of the Tomato chlorosis virus (ToCV) (genus Crinivirus, family Closteroviridae) encodes an RNA silencing suppressor, the protein p22, that has been described as having one of the longest lasting local suppressor activities when assayed in Nicotiana benthamiana. Since suppression of RNA silencing and the ability to enhance disease severity are closely associated, we analyzed the effect of expressing p22 in heterologous viral contexts. Thus, we studied the effect of the expression of ToCV p22 from viral vectors Tobacco rattle virus (TRV) and Potato virus X (PVX), and from attenuated suppressor mutants in N. benthamiana plants. Our results show that although an exacerbation of disease symptoms leading to plant death was observed in the heterologous expression of ToCV p22 from both viruses, only in the case of TRV did increased viral accumulation occur. The heterologous expression of ToCV p22 could not complement suppressor-defective mutant viruses [ABSTRACT FROM AUTHOR]

Streptococcus pyogenes appears to be almost exclusively restricted to humans, with few reports on isolation from animals. We provide a detailed characterization (emm typing, pulsed-field gel electrophoresis [PFGE], and multilocus sequence typing [MLST]) of 15 S. pyogenes isolates from animals associated with different clinical backgrounds. We also investigated erythromycin resistance mechanisms and phenotypes and virulence genes. We observed 2 emm types: emm12 (11 isolates) and emm77 (4 isolates). Similarly, we observed 2 genetic linages, sequence type (ST) 26 and ST63. Most isolates exhibited the M macrolide resistance phenotype and the mefA/ermB genotype. Isolates were grouped into 2 clones on the basis of emm-MLST-PFGE-virulence gene profile combinations: clone 1, characterized by the combined genotype emm12-ST36-pulsotype A-speG; and clone 2, characterized by the genotype emm77-ST63-pulsotype B-speC. Our results do not show conclusively that animals may represent a new reservoir of S. pyogenes but indicate the ability of human-derived S. pyogenes isolates to colonize and infect animals. [ABSTRACT FROM AUTHOR]