Background: Toxoplasmosis is a widespread disease in humans and many other species of warm-blooded animals. Among livestock animals, sheep and goat are more widely infected by Toxoplasma gondii. This parasite is a major cause of abortion, with significant economic losses for sheep and goat breeders. Objectives: The polymerase chain reaction (PCR) method was employed to detect of the T. gondii DNA in the milk of sheep and goats based on its B1 gene. Materials and methods:A total of 625 milk samples were collected from 345 sheep and 280 goats from randomly selected flocks of NorthWest of Iran. Results: Of 625 examined milk samples, 19 animals (3.04%) yielded a specific T. gondii B1 fragment (529 bp), of which T. gondii was detected in 16 (4.63%) sheep and 3 (1.07%) goat milk samples. Restriction fragment length polymorphism (RFLP) analysis of the PCR products of T. gondii with AluI restriction enzyme produced only one distinct pattern among all positive samples, which indicates that one RFLP profile of T. gondii exists in the study area. Conclusions: Presence of T. gondii DNA in the milk of sheep and goats raises the possibility that this parasite is transmitted through consumption of raw milk. Since sheep and goats are important milk sources in Iran, there is a high risk of contamination through milk from these hosts due to their susceptibility to infection. Further studies are required on milk producing animals to implement effective control strategies against toxoplasmosis.

Background:The emergence of antimicrobial-resistant bacteria with biofilm formation ability may be a major threat to public health and food safety and sanitation. Objectives: The aim of this study was to determine antibiotic resistance patterns and biofilm production characteristics of Salmonella typhimurium isolated from different species of birds. Materials and Methods:The antibiotic resistance patterns of 38 pre-identified isolates were screened by standard Kirby-Bauer discdiffusion method performed on Mueller-Hinton agar to a panel of 17 antibiotics. The extent of biofilm formation was measured by Microtiter plate (MTP)-based systems. Results: The highest antimicrobial resistance was detected against nalidixic acid (97%), followed by doxycycline (86%), colistin (84%), streptomycin (84%) and tetracycline (84%). All isolates were sensitive to amikacin (100%) and 97% and 95% of the isolates were sensitive to ceftazidime and ceftriaxone, respectively. Twenty one different antibiotic resistance patterns were observed among S. typhimurium isolates. According to the results of the microtitre plate biofilm assay, there was a wide variation in biofilm forming ability among S. typhimurium isolates. Most of the isolates (60.52%) were not capable of producing biofilm, while 26.31%, 7.89%, and 5.26% isolates were weak, strong and moderate biofilm producers, respectively. Conclusions: It was concluded that nearly all S. typhimurium isolates revealed a high multiple antibiotic resistant with low biofilm forming capabilities which proposed low association between biofilm formation and antibiotic resistance of a major food important pathogen.

Salmonella enterica subspecies enterica serovar Typhimurium causes food-borne outbreaks and systemic diseases in humans and animals. groEL gene (also known as mopA gene in S. Typhimurium), possessing conserved sequence, plays an important role in invasion of bacteria. The purpose of present study was to identify the polymorphism of groEL gene among different avians in different regions by PCR-RFLP method. Fifty two S. Typhimurium isolates (Broiler (n = 13), Layer (n = 12), Duck (n = 5), Goose (n = 5), Sparrow (n = 8), Canary (n = 3), Pigeon (n = 5) and Casco parrot (n = 1). were identified using serotyping as well as multiplex-PCR. Then, amplification of groEL gene performed and amplified products subjected to restriction digestion with BsuRI enzyme. Three RFLP profiles, A, B and C, generated DNA fragments between approximately 100-1,000 bp in size, were observed. The RFLP profile A was observed in 35 (67.3%), profile B in 14 (26.9%) and profile C in 3 (5.77%) of isolates. S. Typhimurium isolates recovered from 13 broilers (two of which profile A, 9 profile B and 2 profile C) and from 8 sparrows (two of which profile A, 5 profile B and 1 profile C) showed all three profiles, but 12 layers and other avians (including Canary (n = 3), Goose (n = 5), Duck (n = 5), Pigeon (n = 5) and Casco parrot (n = 1)) showed profile A. None of these profiles was allotted for a special region. The result of present study showed that S. Typhimurium undergoes genetic mutations in groEL gene under unpleasant milieu in different regions and in different avians. Thus, genetic diversity, despite conserved nature of groEL gene in S. Typhimurium, may exist but it depends on the condition where bacteria have settled. To our knowledge, three RFLP profiles of groEL gene generated by BsuRI restriction enzyme were not reported previously.

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