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Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are one of the most important multidrug resistant microorganisms that threaten human health. Objective: The present study was conducted to evaluate genotypic and phenotypic characteristics of erythromycin resistance among MRSA isolates recovered from raw milk in Iran. Materials and Methods: A total of 50 MRSA isolates were recovered from raw milk. Tests for erythromycin and clindamycin susceptibility and inducible clindamycin resistance were done. In addition, the presence of the methicillin resistance determinant (mecA), erythromycin resistance genes (ermA, ermB, ermC and msrA) and an important virulence gene (Panton– Valentine leukocidin) were investigated using polymerase chain reaction (PCR) method. Results: Forty-eight percent (24/50) and 46% (23/50) of the isolates were resistant to erythromycin and clindamycin, respectively. Seven (14%) isolates showed inducible clindamycin resistance phenotype. The mecA gene was detected in 88% (44/50) of MRSA isolates. The incidence of the ermA, ermB, ermC and msrA genes was 14%, 64%, 12%, and 26%, respectively and the PVL gene was present in 18% (9/50) of MRSA isolates. Conclusion: According to the results of the study, the incidence of erythromycin resistance genes and inducible clindamycin-resistant MRSA strains was high in raw milk samples in Iran.

Background: One of the most important foodborne pathogen which causes enteritis is Salmonella enteritidis (SE). Human cases are mostly associated with the consumption of eggs and poultry meat. Objective: An experiment has been carried out to evaluate the impacts of a yeast product as liquid prebiotic on bacterial shedding, performance indices, and some breast meat characteristics of broiler chickens challenged with SE. Materials and Methods: A total of 90 one-day-old male broiler chicks (Ross 308) were randomly assigned to three different groups with three replicates for each treatment. The treatments were as follows: (1) CONT: birds were not challenged, (2) SE: birds were challenged with SE and fed with a control diet without prebiotic, and (3) SE+PREB: birds were challenged with SE and fed with liquid prebiotic. The challenge with SE was performed on birds in groups 2 and 3 at 28 days of age. Performance parameters and Salmonella shedding were determined on days 7 and 14 post infection. Twelve birds per treatment were sampled at the end of the trial for evaluating characteristics of breast meat. Results: The challenged birds which received prebiotic showed significantly higher body weight gain, lower feed intake, and lower SE shedding than SE group (P

Background: Tetracycline is one of the important antibacterial agents which is used against various bacterial infections. Different bacterial species and strains convey various tetracycline resistance (tetr ) genes. Objective: The present study was conducted to evaluate the occurrence of five tetr genes (tetA, tetB, tetC, tetD, and tetM) among Salmonella serovars obtained from humans and animals. Materials and Methods: A total of 60 different Salmonella strains previously recovered from humans, poultry, and animals were subjected to polymerase chain reaction (PCR) and sequence analysis of the genes. Results: In total, 6 strains were positive for the presence of tetA gene; three serotypes were also positive for the presence of tetC gene. The sequence analysis and phylogenetic tree showed similarities between the sequences of serovars in the present study and other Salmonella serovars and some other bacteria species in GenBank data. Conclusion: The results showed the great distribution of tetracycline resistance genes among Salmonella serovars with different sources which could be the effect of widespread use of the antibiotic particularly in the animals breeding farms.

An experiment was carried out to evaluate the effects of Echinacea purpurea (EP) extract at 5 levels (0, 0.25, 0.5, 1 or 2 mL L-1 of drinking water) on performance, internal organs and gut microflora of Japanese quail (Coturnix coturnix Japonica). The results showed that EP extract decreased feed intake and body weight gain of quails. The feed conversion ratio of quails fed with EP extract at the level of 0.5 ml L-1 drinking water was significantly decreased compared to the control group. Adding EP extract at the levels of 0.25, 0.5 or 1 mL L-1 drinking water decreased carcass yield of the birds (p < 0.05). The relative weight of internal organs of the birds fed different levels of EP extract was not significantly different. Birds consumed EP extract at the levels of 1 or 2 mL L-1 drinking water had lower ileal aerobic bacteria population compared to the control group; however, the ileal Coliform population increased by EP extract supplementation (p < 0.05). Results of the present study indicated that using EP extract at the level of 0.5 mL L-1 drinking water could improve feed conversion ratio of quails; however, it decreased the carcass yield of the birds. RESUMO. Um experimento foi realizado para avaliar os efeitos do extrato de Echinacea purpurea (EP) em 5 concentrações (0, 0,25, 0,5, 1 ou 2 mL L-1 de água potável) sobre o desempenho, órgãos internos e microflora intestinal de codornas japonesas (Coturnix coturnix japonica). Os resultados mostraram que o extrato diminuiu a ingestão alimentar e o ganho de peso corporal de codornas durante todo o período de estudo. A taxa de conversão alimentar de codornas alimentadas com extrato EP ao nível de 0,5 mL L-1 foi significativamente menor em relação ao grupo controle. A adição de extrato EP aos níveis de 0,25, 0,5 ou 1 mL L-1 diminuiu o rendimento de carcaça das aves (p < 0,05). O peso relativo dos órgãos internos das aves alimentadas com diferentes níveis de extrato EP não diferiu significativamente. As aves que consumiram o extrato EP nas concentrações de 1 ou 2 mL L-1 apresentaram uma menor população de bactérias aeróbicas no íleo em comparação com o grupo controle; no entanto, a população ideal de Coliform aumentou nas aves suplementadas com extrato EP (p < 0,05). Nossos resultados indicaram que o uso de extrato EP no nível de 0,5 mL L-1 de água potável melhora a taxa de conversão alimentar das codornas, no entanto, diminui o rendimento de carcaça dos animais.

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗ, Pet birds can harbor human pathogens and contribute to the transmission of infectious agents to human. Since many people are interested in keeping pet birds, this study was conducted in pet birds from Mazandaran province, northern Iran. Totally, 174 fecal samples of pet birds (cockatiel, canary, lovebird, parrot, mynah, goldfinch, budgerigar, macaw, dove, pigeon, and bulbul) were collected with sterile cotton swabs and submitted to Faculty ofVeterinary Medicine, Department of Pathobiology (Amol, Iran). After extraction of total DNA, the samples subjected to molecular detection of the Campylobacter, Salmonella, and Arcobacter using polymerase chain reaction. A total of 114 (65.5%), 28 (16%), and 86 (49.4%) samples were found positive for Campylobacter, Salmonella, and Arcobacter, respectively. Furthermore, some birds showed contamination with two or all three of these bacteria. Results showed that mentioned bacteria can be detected from the apparently healthy pet birds. Therefore pet birds can be considered as potential carriers of these enteropathogens.

Extended-spectrum β-lactamases (ESBLs) are enzymes that hydrolyze the β-lactam ring, and ESBL-producing E. coli has rapidly spread worldwide with pose a serious hazard for humans. The aim of this study was to determine the prevalence of ESBL producing E. coli and molecular evaluation of four ESBL-associated genes among E. coli strains isolated from milk and cheese in southern Iran. Antibiotic susceptibility test was carried out for a total of 150 isolates of E. coli, previously collected from dairy products. ESBL production was screened using a double-disc synergy test (DDST) and presence of four ESBL genes (PER, VEB, TEM and CTX-M) was tested using PCR. Among 150 E. coli strains 57 (38%) isolates were identified as ESBL-producing strains. All ESBL positive isolates could be typed for one or more genes and the most prevalent ESBL-associated gene was CTX-M (80.7%). The PER gene was not present among isolates. Isolates showed high susceptibility to imipe¬nem and cefoxitin. The results showed the high prevalence of ESBL producing E. coli strains among dairy products and high occurrence of CTX-M-associated ESBL activity among isolates indicating the hazards of increasing the strains with antibiotic resistance which can transfer to human trough the dairy food products.

Background: Prevention of foodborne pathogens is essential to control infectious diseases; Salmonella spp. is referred to as the most common causative agent of foodborne illnesses. Objectives: The current study aimed to determine the prevalence of Salmonella enterica subsp. enterica in broiler flocks in Mazandaran province, north of Iran and find the potential risk factors including: age, size of flock, strain, season, vaccination program and use of antibiotics. Materials and Methods: From March 2012 to December 2013, a total of 50 flocks were selected in slaughterhouse and 20 cloacal samples were collected from each flock. Every five samples were pooled and investigated for Salmonella spp. using polymerase chain reaction (PCR). Results: Thirteen flocks out of 50 (26%) were positive for Salmonella species. Chances of Salmonella spp. detection was higher in flocks with lower age (P = 0.41). Increasing flock population was associated with increased chance of Salmonella spp. isolation (P = 0.21). The risk of salmonellosis in broiler flocks was increased when no antibiotics were given to day-old chicks. There was no significant difference (P = 0.30) in the prevalence of salmonellosis among different broiler strains. Conclusions: In the current study, six risk factors were assessed for Salmonella spp. contamination in broiler flocks. Some of these factors contributed to the risk of salmonellosis in broiler flocks.

Backgrounds: Urinary Tract Infection (UTI) is one of the most common bacterial diseases worldwidethat can be presented asymptomatic or symptomatic, characterized by a wide range of symptoms from mild irritative voiding to bacteremia, sepsis, or even death. In latter decades, widespread utilization of antibiotics has resulted in increased incidence of antibiotic resistance among urinary tract pathogens all over the world. Objectives: The aim of this study was to determine patterns of antibiotic resistance bacteria isolated from urinary tract infections in the city of Karaj, Iran. Materials and Methods: This descriptive study was conducted in the city of Karaj from November 2009 to August 2010. Bacterial isolates were identified by standard biochemical tests. Antibacterial susceptibility test was performed by Kirby-Bauer method against some common antibiotics for Gram negative and Gram positive bacteria and the data were analyzed by SPSS software, version 12.0.1. Results: In this study, 230 (8.06%)out of 2852 patients showed positive urine cultures of which there were 204 (88.69%) females and 26 (11.3%) males. 180 (83.17%) cases of isolated bacteria were Gram negative bacilli while 50 (21.73%) cases were Gram positive cocci. E. coli isolates, as the most frequent Gram negative bacteria, showed high resistance to cephalothin (88.16%) and high susceptibility to nitrofurantoin (90.78%). Also Staphylococcus saprophyticus isolates, as the most frequent Gram positive bacteria, exhibited high resistance to ampicillin, tetracycline, and erythromycin (92.31%) and high susceptibility to nitrofurantoin and vancomycin (92.3%). Conclusions: considering the results of this study, E.coli isolates were the predominant pathogens in UTI. Our data demonstrated that antibiotics with the highest activity included ciprofloxacin and nitrofurantoin and those with the least activity included ampicillin and sulfamethoxazole-trimethoprim. Our findings reinforce the need for ongoing investigations to show the trends of antibiotic resistance which can help antibiotic prescription in the clinics.

Background Thermophilic campylobacters, particularly Campylobacter jejuni and C. coli are the main agents of human campylobacteriosis. Campylobacter contaminated chicken products is the most important source of foodborne gastroenteritis. Evaluation of genetic diversity among Campylobacter population is critical for understanding the epidemiology of this bacterium and developing effective control strategies against Campylobacter infections and other related disorders. Objectives The aim of this study was to investigate the polymorphism of thermophilic Campylobacter isolated from broiler fecal samples in Shiraz, southern Iran. Materials and methods Ninety Campylobacter isolates were recovered from broiler feces using enrichment process followed by cultivation method. The isolates were species typing on the basis of polymerase chain reaction (PCR) detection of 16SrRNA and multiplex PCR for determining two thermophilic species. To evaluate strain diversity of thermophilic Campylobacter isolates, flaA PCR-Restriction Fragment Length Polymorphism (RFLP) was performed using DdeI restriction enzyme. Results All 90 Campylobacter isolates confirmed by m-PCR were successfully typed using flaA-PCR-RFLP. Eleven different types were defined according to flaA-typing method and the RFLP patterns were located at three separate clusters in RFLP image analysis dendrogram. Conclusions Campylobacter jejuni isolates significantly showed more variety than C. coli isolates. A relatively low genetic diversity existed among C. jejuni and C. coli isolated from broilers in Shiraz, southern Iran. In our knowledge, this was the first report of genetic diversity among broiler originated human pathogen thermophilic campylobacters in Shiraz, southern Iran.

Background: Several genetic mechanisms are used by Campylobacter spp. to achieve pathogenesis. One of the involved virulence factors is lipooligosacharide-associated genes, which are related to ganglioside mimicry by Campylobacter species. Objectives: The current study was conducted to determine the genetic diversity of 3 LOS-associated genes among Campylobacter jejuni and C. coli isolated from animal fecal samples. Methods: One hundred broiler, cattle, and sheep fecal C. jejuni and C. coli isolates, which had been collected previously from Shiraz slaughterhouses and had been formerly identified by polymerase chain reaction (PCR) reactions, were used in the present study. Campylobacter species were subjected to detect wlaN, cgtB, and waaC genes. The PCR products of three LOS-genes were subjected for restriction fragment length polymorphism (RFLP) using HindIII and AluI restriction enzymes in separate reactions. The most prevalent RFLP patterns in the combination of 2 enzymes were subjected for sequencing and sequence analysis software. Results and Conclusions: Patterns of RFLP for PCR products of all 69 wlaN and 29 cgtB genes were similar yet among 86 waaC gene PCR products, 6 different RFLP patterns were obtained. In conclusion, PCR-RFLP analysis demonstrated considerable variation in gene content and overall sequence heterogeneity in the animal-associated C. jejuni and C. coli LOS biosynthesis genes.

Background: Campylobacter is one of the leading bacterial species causing foodborne illnesses in humans. Antimicrobial agents have been extensively used for treatment of Campylobacter infections; but in the recent years, both animal and human isolates of this bacterium have shown resistance to several antibiotics such as tetracycline. Objectives: The aim of this study was to investigate the presence of genetic determinants of tetracycline resistance in Campylobacter spp. recovered from poultry carcasses in Shiraz, Iran. Materials and Methods: Eighty-three thermophilic Campylobacter spp. Isolates were first identified based on multiplex polymerase chain reaction (PCR) and then screened for presence of tetracycline resistance genes (tet (A), tet (B), tet (O) and te (S)) by PCR. Results: The overall prevalence of Campylobacter jejuni and C. coli among the examined isolates was 51.8% and 48.2%, respectively. Tetracycline resistance genes of tet (B) and tet (S) were not seen among these Campylobacter spp. Isolates, whereas the most common tet gene identified was tet (O), found in 83.1% (69/83) of all the isolates. The tet (O) gene sequence comparison between C. jejuni and C. coli showed 100% similarity and these sequences (JX853721and JX853722) were also identical to the homologous sequences of other strains of Campylobacter spp. existing in the GenBank databases. In addition, tet (A) was found in 18% (15/83) of Campylobacter spp. isolates. To our knowledge, this represents the first report of tet (A) in Campylobacter spp. There was 100% homology between the sequences of tet (A) from this study (JX891463 and JX891464) and the tet (A) sequences mentioned for other bacteria in the GenBank databases. Conclusions: The high prevalence of tet (O) resistance gene along with new detection of tet (A) resistance gene in Campylobacter spp. isolated from poultry carcasses revealed an extensive tetracycline resistance among Campylobacter isolates from poultry in Iran. It emphasized the need for cautious use of tetracycline in poultry production to decrease the extension of tetracycline-resistant Campylobacter spp.

Background: This study aimed to investigate the bacteria associated with urinary tract infection (UTI) and antibiotic susceptibility pattern of the isolates during 2013–2015 in Northern Iran. Materials and Methods: Overall 3798 patients with clinical symptoms of UTI were subjected as samples, and they were cultured and pure isolated bacteria were identified using biochemical tests and subjected to antibiogram assessment using disc diffusion method. Results: Totally, 568 (14.96%) from 3798 patients had positive UTI. Four hundred and ninety-seven (87.5%) from 568 isolated bacteria were resistant to at least one antibiotic. Escherichia coli, Staphylococcus spp., and Pseudomonas spp. were the most prevalent bacteria. Isolated bacteria indicated the highest antibiotic resistance to methicillin (76.06%) and ampicillin (89.29%) and also revealed the most sensitivity to imipenem (99.1%) and amikacin (91.57%). Statistical analysis of the resistance pattern trend during 3 years indicated the insignificant increase (P > 0.05) in antibiotic resistance of the isolates. Conclusion: The results of this study revealed a great concern for emerging UTI-related multidrug-resistant strains of bacteria causing UTI in Iran.

The virulence plasmid associated Salmonella plasmid virulence (spv) locus is strongly concomitant with strains that cause non typhoid bacteremia. The spv region contains three genes required for the virulence, the positive transcriptional regulator spvR and two structural genes spvB and spvC. The purpose of this study was to investigate the presence of these three genes among salmonella serotypes isolated from different sources. A collection of 60 salmonella serotypes from different sources were used. Polymerase chain reaction was carried out for the presence of these genes using specific primers. The prevalence of spvB, spvC, and spvR genes were 26 (43.3 %), 44 (73.3 %), and 28 (46.6 %), respectively. The findings revealed that the distribution of these genes was dissimilar among these serotypes. Many of the human pathogenic salmonella strains which can be transmitted by animals may have these genes and can be very injurious for public health.

We used the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) technique to discriminate the major emerging poultry pathogen, Mycoplasma gallisepticum (MG), in broiler and chukar par - tridge cases referred to the veterinary medicine teaching hospital. Amazingly, the chickens and partridges random amplified polymorphic DNA (RAPD) patterns were similar. This suggests the risk of a common source for the strains isolated from the different animals and illustrates the necessity of novel and improved control programs to prevent and restrict this significant disease which is prevalent among poultry species.