فهرست مطالب ali goudarztalejerdi

Bartonella species are lesser-known pathogenic bacteria that infect a wide range of domestic and wild animals as well as humans. Currently, out of 40 Bartonella species/subspecies, at least 17 are associated with clinical signs in humans and animals. However, despite the zoonotic importance of bartonellosis, there is limited information about prevalence and species infecting dogs and cats in Iran. The aim of this study was molecular identification of Bartonella species in dogs and arthropods infesting them in Hamedan and Kermanshah cities in the west of Iran. Blood genomic DNA (gDNA) was extracted from 100 dogs (45 from Hamedan and 55 from Kermanshah) and, of 25 Ctenocphalides canis fleas, six Pulex irritans fleas and 12 Rhipecephalus sanguineus ticks collected from nine infested dogs were examined for the presence of Bartonella species. Conventional PCR targeting fragments of ITS and rpoB genes was performed, and PCR-positive samples were sequenced bidirectionally and analyzed phylogenetically. Out of 100 dogs, 14 dogs (14%, ten from Hamedan and four from Kermanshah) were found infected with Bartonella species. Nucleotide sequencing confirmed the presence of four Bartonella species in the examined population i.e. Bartonella vinsonii subsp. berkhoffii and Candidatus B. merieuxii in dogs. None of the examined fleas scored positive but one Rh. sanguineus tick from a blood-negative dog was infected with Bartonella DNA. Results of the present study showed the presence of different zoonotic Bartonella species in dogs of Hamedan and Kermanshah cities highlighting the importance of this vector-borne infection. Effective ectoparasite control strategies, regular examination of pet and urban dogs and cats and successful chemoprophylaxis are suggested.

Today, food-borne diseases are known as one of the most important public health concerns in many countries. Campylobacter is one of the most prevalent food-borne pathogens. Raw chicken meat has been reported as the main source of human campylobacteriosis. The present study was conducted to investigate the prevalence of Campylobacter species among broiler carcasses at industrial slaughterhouses in Hamedan province, west of Iran.

Totally, 100 samples were collected using sterile swabs from chicken skin at the post-scalding stage. The samples were enriched in Brucella broth containing Campylobacter selective supplement and incubated at 42ºC for 48-72 hours under microaerophilic conditions. The molecular detection and identification of Campylobacter species were performed by the polymerase chain reaction (PCR) using cadF and Hip primers for detecting Campylobacter species and Campylobacter jejuni, respectively.

The results of this study revealed that 81% and 31% of broiler carcasses were positive for the presence of Campylobacter species and C. jejuni, respectively.

Due to the high contamination rate of chicken meat with this pathogen, precise hygienic control of poultry meat and an increase in consumer awareness seem necessary to decrease human campylobacteriosis.

Staphylococcus aureus, as a major food-borne pathogen, is the most commonly isolated bacterium from bovine mastitis. However, some S. aureus strains exhibit a high rate of antibiotic resistance, among which, methicillin-resistant S. aureus (MRSA) is very important. The present study was conducted to isolate, characterize, and determine the antibiotic resistance profile of MRSA strains in milk.

Staphylococcus aureus strains were isolated and identified from 415 milk samples collected from apparently healthy cattle in Hamedan province, Iran. Molecular characteristics of the strains were identified using multiplex polymerase chain reaction (PCR) and the antibiotic resistance profile of the isolates was determined by Kirby-Bauer disk diffusion susceptibility test.

A total of 76 S. aureus strains were isolated and identified. The PCR results indicated that 50 (65.78%) isolates possessed mecA gene and were found to be MRSA strains. Twelve isolates (15.78%) showed phenotypic resistance to oxacillin in disk diffusion method. All 76 S. aureus isolates (100%) were resistant to penicillin and susceptible to ciprofloxacin and gentamicin.

The results of the present study indicated that bovine milk may contain MRSA strains and this is worrying as these isolates may transfer multi-drug resistance to the isolates that circulate among humans, animals, and food chains.

Calf diarrhea is one of the significant problems in dairy farms associated with treatment costs and reduced livestock production. Salmonellae are among the most common and the major causative agents of diarrhea in calves and humans. The present study was carried out to isolate and identify Salmonella in fecal samples of calves in industrial dairy farms of Hamedan and to determine antibiotic resistance profiles of the probable isolates.

Salmonella were presumptively isolated based on the cultural characteristics and biochemical tests, and the identity of the isolates was further confirmed using genus- and serotype-specific PCR assays. Kirby-Bauer disk diffusion method was performed to determine antibiotic resistance profiles of the isolates.

Out of 120 stool samples collected from 8 industrial farms, 22 (18.33%) isolates possessing rfbJ, fliC and fljB genes were identified as Salmonella Typhimurium serotype. Antibiotic susceptibility test revealed all isolates (100%) were susceptible to gentamicin, amoxicillin-clavulanic acid, kanamycin, and ciprofloxacin and resistant against cotrimoxazole, cefazolin, and cefixime.

To our knowledge, this study was the first report of Salmonella infection in Hamedan's dairy farms, indicating a relatively high prevalence rate of S. Typhimurium infection as the only detected serotype. Antibiotic resistance should also be considered a severe public health concern. Thus, effective hygiene measures should be adopted to prevent or reduce the infection, and monitoring antibiotic susceptibility is required to choose the drug of choice for treatment.

Bacterial diseases in aquaculture fishes are one of the most important risk factors in fish industry. Aeromonas hydrophila is the main causative agent of hemorrhagic septicemia in warm-water fishes, especially Cyprinidae that plays an important role in public health through consumption of contaminated fish meat that can cause gastroenteritis, traveler’s diarrhea, wound infection, pneumonia, and meningitis. Considering the importance of culturing Cyprinidae in Gilan province and the need to identify and detect the presence of A. hydrophila in Cyprinidae fishes suspected with hemorrhagic septicemia, this study aimed to isolate and identify A. hydrophila in Cyprinidae fishes suspected with hemorrhagic septicemia in Gilan province. In this Experimental study, during summer and autumn of 2020 by referring to 71 different warm fish farms of Gilan province, 100 specimens of Cyprinidae fishes were collected. A. hydrophila strains were isolated from the surface wounds (n=15) and kidney (n=85) of fish suspected to hemorrhagic septicemia by inoculation of samples on blood and MacConkey agar media. Among samples from fish kidneys and skin wounds, 51 samples were positive for A. hydrophila. Forty two isolates were confirmed as A. hydrophila by PCR technique using specific primers which targeted 16S rDNA gene fragment. Due to the significant role of A. hydrophila in Cyprinidae mortality in Gilan province, preventive and diagnostic strategies are necessary to control the occurrence of hemorrhagic septicemia by undertaking identification tests of A. hydrophila in fish pools that can reduce costs in fish industry management.

Brucella, causative of brucellosis, has some potential virulence factors involved in Brucella replication and its strategies to circumvent the immune response. One of them is the virB gene that encodes the type ІV secretion system proteins (T4SS) involved in intracellular replication of organism. Brucella virulence factor A (bvfA), and urease (ure) has also been described as being implicated in survival, and virulence in the hosts. The aim of this study was to investigate the B. melitensis virulence factor genes among Brucella isolated from aborted fetuses of sheep and goats in Fars province, southern Iran. A total of 42 isolates of B. melitensis isolated from aborted fetuses between 2005-2011 in Fars province of Iran was used in this study. PCR assay was performed in order to detect the virB, bvfA, and ure genes using specific primers.Results and The frequency of bvfA, virB, and ure genes was 78.50%, 73.80%, and 88.09% among all isolates respectively. The results of the present study showed that most Brucella isolates from this region have virulence factors genes (virB, bvfA, ure) in their genome, and most B. melitensis had ure genes that has been hypothesized to play a role in the pathogenesis of disease.