To identify the barley yellow rust pathotypes، yellow rust samples of were collected from barely، wild barley (Hordeum morinum) and wheat in different provinces of Iran. Isolates were identified as P. striiformis f. sp. hordei or P. striiformis f. sp. tritici based on virulence on barley or wheat differential seedlings، respectively. Virulence factors and pathotypes of barley yellow rust were determined based on avirulence/virulence formula. Totally، ten pathotypes were identified in this study، of which seven were new pathotypes for the world. Some of pathotypes may be the result of hybridization between the two formae speciales، since they exhibited virulence on a number of wheat differentials and triticale in addition to barley differentials. The pathotypes PSH-87 and PSH-84 with six virulence factors had the widest virulence spectrum and two pathotypes PSH-51 and PSH-85 with three virulence factors had narrow virulence spectrum. None of the pathotypes had virulence on resistance genes rpsEm1 and rpsEm2 and only one pathotype had virulence on each of resistance genes Rps4 (Yr4)، rpsHF، rpsVa1، rpsVa2 and Rps1. c. The highest virulence frequency was determined for genes rpsHi1، rpsHi2 (0. 83%) and rps2 (0. 67%). The genes which were effective against all or majority of pathotypes can be used as resistance sources in breeding programme for cotrolling barley yellow rust.

Yersinia species are gram negative bacteria that are responsible to cause diarrhea in humans. Due to insufficient knowledge on the effect of pH and temperature in virulence properties of Yersinia spp, this study was conducted to evaluate these factors on virulence properties Yersinia. This was an experimental study performed in two stages on 12 virulence and 7 non-virulence such as Y. enterocolitica, Y. intemedia, Y. fredeniksenii, and Y. kristensenii, which were isolated from different sources. In the first part the impact of pH and temperature on bacterial growth and in the second part of the study the effects of pH and temperature on virulence characteristics of Yersinia spp. were studied by using auto- agglutination test, dependence on calcium, crystal violet, esculin and salicin tests, invasion of Hep-2 cell and RPMI-1640. Temperature and pH were effective on bacterial growth independently without influencing each other. The results showed that temperature was effective on virulence characteristics while pH did not reduce the virulence effect. Furthermore, crystal violet, RPMI-1640 and invasion of Hep-2 cell were more effective in virulence factor. Besides some strains maintained the virulence property during the growth, this might be due to stability of plasmid in such strain. The results showed that both pH and temperature were effective on the growth, but only temperature is effective on virulence properties.

The aim of present study was to detect some important virulence genes of Staphylococcus aureus that were isolated from clinical and subclinical mastitis cases and their correlation with Somatic Cell Count (SCC) as inflammatory indicator of udder was found. Presence of six important genes “clfA, coa, SpaA, agrIII, hla and hlb” encoding clamping factor, coagulase, X region of protein A gene spa, accessory gene regulator, hemolysin A and hemolysin B, respectively, were detected using PCR and the results were compared with SCC. After statistical analysis, a significant correlation between virulence genes and increase in somatic cells was observed (P ≤ 0/05). According to the results, the six virulence gene patterns except one, were presented only in the clinical mastitis isolates and all these isolates were corelated to SCC above 5000000 cell/ml. According to the results, increase in virulence genes that were present in Staphylococcus aureus could lead to change the signes of intra mammary infection from subclinical to clinical mastitis. Furthermore, the results indicates that increasing in the number of virulence genes present in Staphylococcus aureus improves virulence of bacteria to damage mammary tissues, which leads to increase in SCC.

Lactic acid bacteria, including lactobacilli, enterococci, leuconostoc and weissella species isolated from Iranian traditional fermented camel milk (Chal) were assessed for the incidence of virulence determinants (gelE, efaAfm, efaAfs, ace, espfs, cylM, cylA and cylB), sensitivity to various antibiotics and virulence phenotypes. The incidence of virulence genes was determined by polymerase chain reaction and antibiotic susceptibility was tested by disk diffusion method. The results of this study indicated that all of the strains harbor at least two or more of the virulence genes. The most frequent virulence genes detected among tested strains were cylB, gelE and efaAfs. All strains showed no β-hemolysis while tyrosine decarboxylase activity and gelatinase production were observed in enterococcus and leuconostoc strains. Majority of strains were resistant to Polymyxin B and kanamycin. Lactobacillus strains including L. paraplantarum, L. kefiri, L. paracasei, L. plantarum and Weissella cibaria were resistant to both vancomycin and kanamycin. The possibility of transferring the antibiotic resistance and virulence genes to other starter and commensal strains makes the usage of these strains in food and dairy products controversial without required safety assessments.

Bovine mastitis is one of the epidemic diseases in dairy cattle, that it was created by various infectious agents. The aim of this study was tracking of these bacteria in the cases such as bovine subclinical and clinical mastitis and studying of virulence factors of this bacteria. Overall, 130milk samples were collected from dairy cattle's in the Chaharmahal and Bakhtiyari state scale that they are affected to mastitis and then they were isolated microbial culture and molecular confirmation of Klebsiella pneumonia strains, Presence of the most prevalent of virulence factors in these strains was detected by PCR method. Of 130milk samples examined, 30 samples were positive (15.38%) to Klebsiella pneumonia. Of these strains, the most of virulence factors were detected in this bacteria: so that fimH and papA genes by excess of 65and 90% had the highest prevalent and sfa/focDE gene with 15% presence had the lowest rate of evaluation virulence gene in this isolates. Presence of kinds of virulence factors in the Klebsiella pneumonia isolates will have indicated direct intervention these factors for bacterium pathogen and it is needed to detection of Klebsiella pneumonia pathogen, it must study presence distribution of virulence factors.

The present investigation was carried out to examine virulence diversity among the 291isolates (seven populations) of Rhizoctonia solani AG-1 IA causing sheath blight of rice by sclerotia production and pathogencity studies on four rice cultivars representing different observed disease reactions, using detached leaf inoculation method in conjunction with mycelia growth measuring. Based on pathogencity test four tested cultivars were significantly differed from each other in response to each population of pathogen. In each population, all the test isolates exhibited varying degree of virulence on each four cultivars and were variable both in mycelial and sclerotial (number and weight) parameters. There was found one group in each population having more stable performance in virulence in a range of genetically different rice cultivars based on their virulence on each four cultivars and along with their coefficient of variation by cluster analysis method. According to these finding, six, two, five and one high-virulence isolates respectively from populations of Rasht, Tonekaboon, Amol and Golestan can be used to future greenhouse or field tests, selecting most suitable isolates for identification of accurate reaction of rice cultivars / lines for rice breeding programs in north of Iran.

Enterococci cause meat and environmental contamination during slaughter time. In this study, virulence and antimicrobial resistance (AMR) characteristics of enterococci isolated from chickens were determined. A total of 107 cloacal swabs of chickens were inoculated onto Slanetz and Bartley agar and incubated at 37ºC for 24-48 h. Gram staining, catalase, and hemolytic tests were done. AMR was determined using the disc diffusion technique against twelve antimicrobials. Molecular detection of AMR genes: blaZ, aphA, aacA-aphD, ermB, tetL, tetM, and vanC, and virulence factors: agrBEfs, efaAEfs, esp, gelE, and hyl were done on selected isolates using PCR. Ninety-five isolates were Enterococcus species. The isolates showed resistance to tetracycline, cefoxitin, amoxicillin, and imipenem and possessed tetL, tetM, ermB, aphA, vanC, aaca-aphD resistance and gelE, agrBef, efaAfs, espfs and hyl virulence genes. This is the first detection of AMR and virulence genes in multi-drug resistant enterococci among chickens in the locality. These enterococci could constitute a reservoir of virulence and resistance properties which are of animal and public health concern.

Uropathogenic Escherichia coli (UPEC) are a common causative agent of urinary tract infections. Strains of UPEC encode a number of virulence factors that facilitate their dissemination and persistence within the host. To diminish the burden of UPEC, using effective preventive measures, data on virulence factor prevalence in different geographic regions must be assessed. As no such data was available for this geographic region of Iran, the purpose of this study was to analyze the prevalence of ten UPEC virulence genes among 100 E. coli isolates collected from patients with urinary tract infections (UTI) in Zabol, Iran.Patients and One hundred UPEC obtained from patients with urinary tract infection were screened by the polymerase chain reaction (PCR) with primers specific for the following UPEC virulence genes: astA (enterotoxins), cdtB (enterotoxins), cvi/cva (colicin V operon), ibeA (an invasive protein), iss (increased serum survival protein), iutA (aerobactin), kpsII (group 2 capsule), neuS (K1 polysialyltransferase), tsh (an adhesive and proteolytic protein), and vat (vacuolating autotransporter toxin). Amongst the total of 100 UPEC isolates, 99 (99%) isolates were found to carry the studied virulence genes. Twenty-six different virulence patterns were identified. The prevalence of astA, cdtB, cvi/cva, ibeA, iss, iutA, kpsII, neuS, tsh and vat were 29%, 0%, 19%, 67%, 47%, 99%, 98% 96%, 1% and 18%, respectively. We concluded that major differences exist in the prevalence of virulence factors between different UPEC isolated from different countries. Detecting these genes as primary controllers of UPEC virulence may aid in better management of related infections.

Present study was designed in order to molecular confirmation, capsular typing and detection of 12 important virulence factors include ompH, oma87, sodA, sodC, hgbA, hgbB, exBD-tonB, nanB, nanH, ptfA, pfhA and toxA in 18 Pasteurella multocida avian isolates from different areas of Iran with a strain of the organism was isolated from the epidemic pasteurellosis in the Northern region, and also survey of acute isolates lethality in poultry embryos and pullet. Molecular confirmation of tested isolates was performed using specific primers of kmt1. As well, capsular typing and detection of virulence factors of isolates were performed by application of multiplex PCR method and using specific primers of capsule biosynthesis genes and genes encoding virulence factors of organism. All isolates were confirmed molecularly but based on the results of capsular typing, 16 (88.8%) isolates with strain isolated from epidemic pasteurellosis were identified as type A and 2 (11.1%) as untypeable isolates. Detection of virulence genes showed that all studied isolates has six virulence genes of sodC, hgbA, hgbB, nanB, nanH and ptfA. The oma87, exBD-tonB, ompH, sodA and pfhA genes were respectively present in 94.4, 94.4, 83.3, 66.6 and 27.7% of the isolates, but there was not any toxA positive isolates. To determine the chicken embryo lethal dose 50 (CELD50) and lethal dose 50 (LD50) of the isolates, different dilutions of five acute isolates containing the majority of virulence genes as well as strain isolated from epidemic pasteurellosis were respectively inoculated to embryonated chicken eggs and lying pullets. Based on the results of CELD50, though all six isolates were able to waste the poultry embryos, but strain isolated from epidemic pasteurellosis was recognized as the most acute isolate. Results of LD50 test showed that none of the five acute isolates were able to waste the studied pullets while the LD50 of strain isolated from epidemic pasteurellosis was determined 5 × 101 colony forming unit per bird (cfu/case), and this strain was identified as the most acute understudy isolate. The findings of this study showed that, despite the presence of the majority of virulence genes in P. multocida avian isolates in Iran, and that the most acute isolates were able to waste the poultry embryos but they were not infectious to lying pullets, and virulence of strains isolated from birds with hyperacute form of the disease is far higher. Our data could be useful in the design of new and efficient vaccines that would be acceptable protection in animal populations.

Dumpsites have the potential to serve as reservoirs for various medically important bacteria and their virulence and resistance gene markers. For Vibrio spp., numerous genes associated with virulence have been identified in environmental strains. Due to the specific growth requirements of Vibrio spp., such strains can often be overlooked. This study aimed to assess the potential of Vibrio spp. isolated from two dumpsites in Port Harcourt, Nigeria, to serve as reservoirs of virulence and resistance genes. The soil samples were evaluated for the presence of Vibrio spp. following enrichment, using standard microbiological and biochemical test methods. DNA from Vibrio spp. was extracted using the boiling method, and isolates were tested for the presence of four resistance (sxt, strB, BlaTEM, and dfrA1) and four virulence (ctxA, hlyA, tcpA, and toxR) genes. The study found a 40% occurrence of resistance genes and a 10% occurrence of virulence genes, with the strB streptomycin resistance gene being the most commonly detected (42%). Two of the virulence genes (ctxA and tcpA) were not detected. Seven of the test isolates exhibited multiple gene markers, with four gene markers present in each of two isolates. Overall, the study revealed a generally low potential for Vibrio sp. isolated from the dumpsites in Port Harcourt, Nigeria, to act as reservoirs of virulence and resistance genes. Additionally, the study reported an absence of major virulence markers associated with V. cholerae. A concerning finding was the high occurrence (42%) of the strB gene among these environmental isolates.