scholarly journals Comparative genome analysis of 24 bovine-associatedStaphylococcusisolates with special focus on the putative virulence genes

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4560 ◽  
Author(s):  
Silja Åvall-Jääskeläinen ◽  
Suvi Taponen ◽  
Ravi Kant ◽  
Lars Paulin ◽  
Jochen Blom ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
Subclinical Mastitis ◽  
Special Focus ◽  
Putative Virulence Factor ◽  
Cumulative Number ◽  
Genome Sequences ◽  
Potential Association

Non-aureus staphylococci (NAS) are most commonly isolated from subclinical mastitis. Different NAS species may, however, have diverse effects on the inflammatory response in the udder. We determined the genome sequences of 20 staphylococcal isolates from clinical or subclinical bovine mastitis, belonging to the NAS speciesStaphylococcus agnetis, S. chromogenes,andS. simulans, and focused on the putative virulence factor genes present in the genomes. For comparison we used our previously published genome sequences of fourS. aureusisolates from bovine mastitis. The pan-genome and core genomes of the non-aureus isolates were characterized. After that, putative virulence factor orthologues were searchedin silico. We compared the presence of putative virulence factors in the NAS species andS. aureusand evaluated the potential association between bacterial genotype and type of mastitis (clinical vs. subclinical). The NAS isolates had much less virulence gene orthologues than theS. aureusisolates. One third of the virulence genes were detected only inS. aureus. About 100 virulence genes were present in allS. aureusisolates, compared to about 40 to 50 in each NAS isolate.S. simulansdiffered the most. Several of the virulence genes detected among NAS were harbored only byS. simulans, but it also lacked a number of genes present both inS. agnetisandS. chromogenes. The type of mastitis was not associated with any specific virulence gene profile. It seems that the virulence gene profiles or cumulative number of different virulence genes are not directly associated with the type of mastitis (clinical or subclinical), indicating that host derived factors such as the immune status play a pivotal role in the manifestation of mastitis.

Virulence gene profiles inStaphylococcus aureusisolated from cows with subclinical mastitis in eastern Poland

2016 ◽  
Vol 83 (2) ◽  
pp. 228-235 ◽  
Author(s):  
Barbara Kot ◽  
Piotr Szweda ◽  
Aneta Frankowska-Maciejewska ◽  
Małgorzata Piechota ◽  
Katarzyna Wolska
Keyword(s):  
Staphylococcus Aureus ◽  
Serine Protease ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
Subclinical Mastitis ◽  
Staph Aureus ◽  
Gene Profiles ◽  
Enterotoxin Genes ◽  
Genes Encoding

Staphylococcus aureusis arguably the most important pathogen involved in bovine mastitis. The aim of this study was to determine the virulence gene profiles of 124Staph. aureusisolates from subclinical mastitis in cows in eastern Poland. The presence of 30 virulence genes encoding adhesins, proteases and superantigenic toxins was investigated by PCR. The 17 different combinations of adhesin genes were identified. Occurrence ofeno(91·1%) andfib(82·3%) genes was found to be common. The frequency of other adhesion genesfnbA, fnbB, ebpswere 14·5, 50, 25%, respectively, and forcnaandbbpwere 1·6%. TheetAandetDgenes, encoding exfoliative toxins, were present in genomes of 5·6 and 8·9% isolates, respectively. ThesplAandsspA, encoding serine protease, were detected in above 90% isolates. The most frequent enterotoxin genes weresei(21%),sem(19·4%),sen(19·4%),seg(18·5%) andseo(13·7%). Thetstgene was harboured by 2·4% isolates. The 19 combinations of the superantigenic toxin genes were obtained and found in 35·5% of isolates. Three of them (seg, sei, sem, sen, seo; sec, seg, sei, sem, sen, seoandseg, sei, sem, sen) were the most frequent and found in 16·1% of the isolates. The most common virulotype, present in 17·7% of the isolates, wasfib, eno, fnbB, splA, splE, sspA. The results indicate the variation in the presence of virulence genes inStaph. aureusisolates and considerable diversity of isolates that are able to cause mastitis in cows.

scholarly journals Virulence Factor Gene Profiles of Escherichia coli Isolates from Clinically Healthy Pigs

2006 ◽  
Vol 72 (10) ◽  
pp. 6680-6686 ◽  
Author(s):  
Peter Schierack ◽  
Hartmut Steinrück ◽  
Sylvia Kleta ◽  
Wilfried Vahjen
Keyword(s):  
Escherichia Coli ◽  
Virulence Factor ◽  
Virulence Genes ◽  
Clinical Signs ◽  
Virulence Gene ◽  
Bacterial Populations ◽  
Factor Gene ◽  
E Coli ◽  
Gene Profiles ◽  
Virulence Factor Gene

ABSTRACT Nonpathogenic, intestinal Escherichia coli (commensal E. coli) supports the physiological intestinal balance of the host, whereas pathogenic E. coli with typical virulence factor gene profiles can cause severe outbreaks of diarrhea. In many reports, E. coli isolates from diarrheic animals were classified as putative pathogens. Here we describe a broad variety of virulence gene-positive E. coli isolates from swine with no clinical signs of intestinal disease. The isolation of E. coli from 34 pigs from the same population and the testing of 331 isolates for genes encoding heat-stable enterotoxins I and II, heat-labile enterotoxin I, Shiga toxin 2e, and F4, F5, F6, F18, and F41 fimbriae revealed that 68.6% of the isolates were positive for at least one virulence gene, with a total of 24 different virulence factor gene profiles, implying high rates of horizontal gene transfer in this E. coli population. Additionally, we traced the occurrence of hemolytic E. coli over a period of 1 year in this same pig population. Hemolytic isolates were differentiated into seven clones; only three were found to harbor virulence genes. Hemolytic E. coli isolates without virulence genes or with only the fedA gene were found to be nontypeable by slide agglutination tests with OK antisera intended for screening live cultures against common pathogenic E. coli serogroups. The results appear to indicate that virulence gene-carrying E. coli strains are a normal part of intestinal bacterial populations and that high numbers of E. coli cells harboring virulence genes and/or with hemolytic activity do not necessarily correlate with disease.

Phylogenetic genotyping, virulence genes and antimicrobial susceptibility of Escherichia coli isolates from cases of bovine mastitis

2021 ◽  
Vol 88 (1) ◽  
pp. 78-79
Author(s):  
Nashmil Aslam ◽  
Saeed-Ul-Hassan Khan ◽  
Tahir Usman ◽  
Tariq Ali
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Susceptibility ◽  
Iron Uptake ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
E Coli ◽  
Milk Samples ◽  
Group A ◽  
Mastitic Milk

AbstractThe study described in this research communication used phylogenetic genotyping to identify virulence genes and antimicrobial susceptibility in Escherichia coli recovered from cases of bovine mastitis. From 385 mastitic milk samples, 30 (7.8%) isolates were confirmed as E. coli. Most isolates (80%) belonged to phylo-group A. These 30 E. coli isolates were also screened for 11 different virulence genes. The majority of isolates (63%) harbored no virulence gene. Only 11 (37%) isolates tested positive for two virulence genes, either the iron uptake gene iucD in 3 (10%) isolates or the serum resistance gene traT in 2 (7%) isolates or both traT and iucD in 6 (20%) isolates. The E. coli isolates showed highest susceptibility to gentamicin, meropenem, and pipracillin. Most isolates were resistant to ampicillin, cefotaxime and streptomycin. This study suggests that mastitis causing E. coli might originate from commensal bacteria and that the presence of these virulence genes, common in extra-intestinal pathogenic E. coli (ExPEC) strains could be attributed to high genetic variability of mastitis-causing E. coli.

scholarly journals Molecular Identification Virulence Genes Of Escherichia coli Isolated From Bovine Clinical Mastitis

2014 ◽  
Vol 8 (2) ◽  
pp. 1-3 ◽  
Author(s):  
Gholam Ali Moradli ◽  
Tagi Zahraei Salehii ◽  
Mahmod Jamshidian ◽  
Farhad Mosakhani
Keyword(s):  
Escherichia Coli ◽  
Molecular Identification ◽  
Virulence Genes ◽  
Life Sciences ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
Clinical Mastitis ◽  
Common Gene ◽  
E Coli ◽  
Pcr Assays

The aims of this study were molecular identification some of virulence genes in Escherichia coli isolated from milk of bovines with clinical mastitis. (n = 60) E. coli isolates from acute clinical mastitis were examined for detect the presence of the genes encodingshigatoxin1 (stx1), intimin (eaeA), cytotoxicnecrotizingfactor 2 (cnf2), aerobactin (iucD) and P fimberiae (pap). The majors finding in the PCR assays were: 8 isolates (13.33%) had at least one virulence gene, None of isolates contained the genes for stx1, eaeA , the most common gene in the examined isolate was iucD which was positive in 6 isolates (10%). One isolate (1.66%) was positive for both iucD and pap genes and one isolate (1.66%) for cnf2 gene. In this study similar to previous investigations indicated that prevalence virulence genes in E. coli isolated of bovine mastitis is deferent. The results of this investigate similar to previous studies indicated none of the potential virulence genes or specific pathotype was observed in E. coli isolates from bovine clinical mastitis. DOI: http://dx.doi.org/10.3126/ijls.v8i2.10219   International Journal of Life Sciences Vol.8(2): 2014; 1-3 

scholarly journals Genomic analysis of European bovine Staphylococcus aureus from clinical versus subclinical mastitis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jurriaan Hoekstra ◽  
Aldert L. Zomer ◽  
Victor P. M. G. Rutten ◽  
Lindert Benedictus ◽  
Arjan Stegeman ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Outcome ◽  
Virulence Genes ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Genome Wide Association Study ◽  
Bovine Mastitis ◽  
Subclinical Mastitis ◽  
Clinical Severity ◽  
A Genome

Abstract Intramammary infections (IMI) with Staphylococcus aureus are a common cause of bovine mastitis and can result in both clinical (CM) or subclinical mastitis (SCM). Although bacterial isolates of S. aureus differ in their virulence potential it is largely unclear which bacterial virulence factors are responsible for increased clinical severity. We performed a genome wide association study and used a generalized linear mixed model to investigate the correlation between gene carriage, lineage and clinical outcome of IMI in a collection of S. aureus isolates from cattle with CM (n = 125) and SCM (n = 151) from 11 European countries. An additional aim was to describe the genetic variation of bovine S. aureus in Europa. The dominant lineages in our collection were clonal complex (CC) 151 (81/276, 29.3%), CC97 (54/276, 19.6%), CC479 (32/276, 11.6%) and CC398 (19/276, 6.9%). Virulence and antimicrobial resistance (AMR) gene carriage was highly associated with CC. Among a selection of nine virulence and AMR genes, CC151, CC479 and CC133 carried more virulence genes than other CCs, and CC398 was associated with AMR gene carriage. Whereas CC151, CC97 were widespread in Europe, CC479, CC398 and CC8 were only found in specific countries. Compared to CC151, CC479 was associated with CM rather than SCM (OR 3.62; 95% CI 1.38–9.50) and the other CCs were not. Multiple genes were associated with CM, but due to the clustering within CC of carriage of these genes, it was not possible to differentiate between the effect of gene carriage and CC on clinical outcome of IMI. Nevertheless, this study demonstrates that characterization of S. aureus CC and virulence genes helps to predict the likelihood of the occurrence of CM following S. aureus IMI and highlights the potential benefit of diagnostics tools to identify S. aureus CC during bovine mastitis.

scholarly journals Genomic Analysis of Staphylococcus aureus Isolates Associated With Peracute Non-gangrenous or Gangrenous Mastitis and Comparison With Other Mastitis-Associated Staphylococcus aureus Isolates

2021 ◽  
Vol 12 ◽  
Author(s):  
Silja Åvall-Jääskeläinen ◽  
Joanna Koort ◽  
Heli Simojoki ◽  
Suvi Taponen
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Outcome ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Allelic Variation ◽  
Bovine Mastitis ◽  
Genomic Analysis ◽  
Virulence Gene ◽  
Clinical Mastitis ◽  
Comparative Genomic

Staphylococcus aureus is a highly prevalent cause of mastitis in dairy herds worldwide, capable of causing outcomes that vary from subclinical to peracute gangrenous mastitis. We performed a comparative genomic analysis between 14 isolates of S. aureus, originating from peracute bovine mastitis with very severe signs (9 gangrenous, 5 non-gangrenous) and six isolates originating from subclinical or clinical mastitis with mild to moderate signs, to find differences that could be associated with the clinical outcome of mastitis. Of the 296 virulence factors studied, 219 were detected in all isolates. No difference in the presence of virulence genes was detected between the peracute and control groups. None of the virulence factors were significantly associated with only a single study group. Most of the variation in virulence gene profiles existed between the clonal complexes. Our isolates belonged to five clonal complexes (CC97, CC133, CC151, CC479, and CC522), of which CC522 has previously been detected only in isolates originating from caprine and ovine mastitis, but not from bovine mastitis. For statistical analysis, we sorted the CCs into two groups. The group of CCs including CC133, CC479, and CC522 was associated with gangrenous mastitis, in contrast to the group of CCs including CC97 and CC151. The presence of virulence genes does not explain the clinical outcome of mastitis, but may be affected by allelic variation, and especially different regulation and thus expression in the virulence genes.

Characterization of Escherichia coli Isolated from Bovine Subclinical Mastitis for Virulence Genes, Phylogenetic Groups and ESBL Production

2020 ◽  
Author(s):  
S M Nalband ◽  
R P Kolhe ◽  
P D Deshpande ◽  
S N Jadhav ◽  
D G Gandhale ◽  
...  
Keyword(s):  
Virulence Genes ◽  
Bovine Mastitis ◽  
Subclinical Mastitis ◽  
Esbl Production ◽  
Phylogenetic Groups ◽  
E Coli ◽  
High Prevalence ◽  
Milking Machine ◽  
Esbl Producers

Pathogenic E. coli associated with bovine mastitis are least studied group of microbes in India. Thus an investigation was carried out to know the occurrence of bovine subclinical mastitis and E. coli at different dairy farms. E. coli strains isolated from clinical and environmental samples were screened for virulent genes namely, eae, bfpA, iapH, aggR, elt, est, stx1/stx2; phylogenetic groups and for ESBL production. Findings revealed high prevalence of subclinical mastitis (45%). E. coli strains were isolated from milk, udder, milking machine, floor swabs, etc. Out of 81 E. coli, 38 (46.91%) were ESBL producers. The virulent genes in single or in combination were detected in 55 strains and eae gene was predominant (43.20%). The stx1/stx2 were detected in 2.47% samples. E. coli isolates fall under phylogenetic groups B1 (58.18%), A (23.63%) and D (18.18%). Phylogenetic group B2 was not detected. Dairy cattle could act as a reservoir of ESBL type diarrheagenic E. coli.

scholarly journals Molecular characterization of antimicrobial resistance and virulence genes of Escherichia coli isolates from bovine mastitis

2020 ◽  
Vol 13 (8) ◽  
pp. 1588-1593
Author(s):  
Zuhair Bani Ismail ◽  
Sameeh M. Abutarbush
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Virulence Gene ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Procaine Penicillin

Background and Aim: Mastitis is a common and economically important disease in dairy cattle. It remains one of the most common reasons for the extensive use of antimicrobials in dairy farms leading to the emergence of antimicrobial-resistant pathogens. The aim of this study was to determine the patterns of antimicrobial resistance of Escherichia coli isolates from bovine mastitis and to identify prominent antimicrobial resistance and virulence genes among isolated strains. Materials and Methods: Antimicrobial susceptibility testing against six antibiotic groups, including tetracyclines, aminoglycosides, beta-lactams, macrolides, sulfonamides, and fluoroquinolones was performed using the disk diffusion method. PCR was performed on resistant isolates to detect resistance and virulence genes using commercially available primers. Results: Out of 216 milk samples cultured, 14 samples yielded E. coli isolates. All isolates (100%) were resistant to ampicillin, amoxicillin, procaine penicillin, streptomycin, oxytetracycline, and sulfamethoxazole-trimethoprim. Only one isolate (7%) was sensitive to gentamicin, and all isolates (100%) were sensitive to enrofloxacin and ciprofloxacin. All isolates carried at least one resistance gene against one or more of the major antibiotic groups. All isolates carried the ereA, tetG, tetE, and tetB genes, followed by tetA (93%), ampC (86%), strA (86%), sul1 (78%), tetD (71%), tetC (57%), aadA (57%), and strB (36%). The lowest percentage of isolates carried bla1 (17%) and bla2 (12%) genes, and none of the isolates carried the qnrA gene. Most of the isolates (93%) carried the Shiga toxin 1 virulence gene, followed by complement resistance protein (79%), intimin (64%), Shiga toxin 2 (36%), cytotoxic necrotizing factor (35%), aerotaxis receptor (21%), and type 1 fimbriae (15%). Conclusion: Results of this study indicate that the high percentages of E. coli isolate from bovine mastitis are resistant to two or more of the major antibiotic groups, irrespective of the presence or absence of relevant resistance or virulence genes.

scholarly journals Isolation of Yersinia pseudotuberculosis in bovine mastitis: A potential milk-borne hazard

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Andrea Lorusso ◽  
Luciana Addante ◽  
Loredana Capozzi ◽  
Angelica Bianco ◽  
Laura Del Sambro ◽  
...  
Keyword(s):  
Virulence Genes ◽  
Yersinia Pseudotuberculosis ◽  
Bovine Mastitis ◽  
Raw Milk ◽  
Subclinical Mastitis ◽  
Biochemical Tests ◽  
Safety Hazard ◽  
Milk Samples ◽  
Antibacterial Susceptibility ◽  
Potential Food

This paper describes the first confirmed case of a subclinical mastitis caused by Yersinia pseudotuberculosis in a dairy cow from Italy. Milk samples from an adult cow of the Bruna breed were analyzed accordingly to standard milk cultivation protocols. Bacteriological examinations allowed to isolate atypical Gram-negative rods identified as Y. pseudotuberculosis using biochemical tests. The isolate was subjected to Whole Genome Sequencing (WGS) and the species identification was confirmed using rMLST. Moreover, the virulence and antibacterial susceptibility of the isolate have been also determined. The most common virulence genes were screened through WGS, showing the presence of inv, ail, pil and HPI genes. No antibiotic resistance was found. Even though scarcely described as causal agent of subclinical mastitis, the detection of Y. pseudotubercolusosis suggests that this pathogen could be spread to humans through raw milk, representing a potential food safety hazard.

Vibrio harveyi virulence gene expression in vitro and in vivo during infection in black tiger shrimp Penaeus monodon

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Virulence Gene ◽  
Economic Losses ◽  
Virulence Gene Expression

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.

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