Detection of cytolethal distending toxin [cdt] Genes in Campylo-bacterjejuni and Campylobacter coli isolated from the intestinal of commercial broiler chickens, turkey and quail of Iran

Campylobacter jejuni and Campylobacter coli are zoonotic bacteria which are frequently associated with human diarrhea. Sharing of the cytolethal distending toxin [cdt] genes in Campylobacter is common and is considered species specific. In this study we focused on detecting the presence of cdt gene in C. jejuni and C. coli isolated from broilers, turkeys and quails of Iran. Cecal samples were randomly collected from 240 broiler chickens, 100 meat type turkeys and 100 quails after slaughtering. We used PCR as a method for detecting cdt genes. In broilers, 93% of 58 C jejuni positive samples possessed cdt gene and in all cases the three different subunits of cdt genes were present. However, only 56% of 14 C. coli isolates in broilers had contained cdt genes, while one fourth having all three subunits present. In turkeys, around 65% of 34 C. jejuni positive samples had cdt gene present with 38% possessing all three subunits of cdt genes. But all 5 C. coli isolates had all three subunits cdt gene. In quails, 67% of 30 C. jejuni positive samples were identified by cdt gene, 20% of those possessed all three gene subunits. On the other hand, all 28 C. coli isolates of quails had cdt gene present while 36% of those held all three gene subunits. Our data is indicating the isolation, culture and cdt PCR amplification approaches in this study seemed to be efficient. However, the presence of different variation of Campylobacter cdt gene types in our sample isolates signifies the necessity of further functional gene studies to elucidate which gene type combinations result in encoding effective toxins

[Construction of mutant WbkA gene in Brucella abortus S19 by overlap extension PCR]

Background: Causing site direct mutation can be one of the efficient methods to evaluate the characteristics and properties of various genes. Brucellosis is the most common zoonotic infectious disease that would cause great economic losses. Thus, recognition of pathogenic and immunogenic factors in the genus Brucella can lead to control this health problem

Objectives: Considering the importance of site direct mutation in identification of genome structure and numerous ways to achieve this goal, Overlap Extension PCR is introduced as an improved technique for the removal and replacement of the gene target

Methods: For this study, with two-step PCR using specific primers, upstream and downstream fragments from target gene and antibiotic resistance cassette from plasmid pET28a [+], were reproduced and were connected to each other. The resulting fragment was cloned in specific position of pBluescriptIISK[-] plasmid by the restriction enzymes. Then, the construction was transferred into the genome of Brucella abortus by electroporation method

Results: Fusion PCR product was obtained without any change in the nucleotide sequence and then it was cloned into pBluescriptIISK [-] plasmid, finally the construction was replaced and the target gene was deleted

Conclusions: The results of this study show that the Overlap Extension PCR is an optimized and modified technique to create mutations in the bacterial genome structure and can easily be used in the family Brucella

[Molecular identification of Salmonella Infantis isolated from backyard chickens and detection of their resistance genes by PCR]

This study aims at molecular identification of Salmonella Infantis isolated from backyard chickens and the detection of their antibiotic resistance genes. A total of 46 Salmonella-suspected samples isolated from backyard chickens of northern Iran were collected. Serotyping was done by the traditional method and then confirmed by PCR. Antimicrobial susceptibility of the isolates against 13 antimicrobial agents was determined by the standard disk diffusion method. There were 44 samples identified as Salmonella. Serotyping results showed that all 44 isolates belonged to serogroup C1 and serovar Infantis. The most resistance observed was to tetracycline and doxycycline [100%], chloramphenicol [79%] and florfenicol [72%]. The floR, catI, tetA and tetG genes were used for the detection of florfenicol chloramphenicol and tetracycline resistance. In order to identify the phenotypic resistance in strains which showed resistance genes by PCR, colony PCR and culture on plates each containing antibiotic was performed simultaneously. All the Salmonella Infantis resistant to florfenicol and chloramphenicol harbored floR and catI. None of the Salmonella resistant to tetracycline carried tetA or tetG. The result of colony PCR and culture in antibiotic medium confirmed the results of PCR and indicated phenotypic resistance in these samples.

Giant hydronephrosis and secondary pyelonephritis induced by Salmonella dublin in a Holstein calf

Hydronephrosis occurs as a congenital or an acquired condition following obstruction of the urinary tract. In this study, a four month old male Holstein calf with emaciation, growth retardation and a poor dry scruffy hair coat was examined because of remarkable distention of right abdomen. At necropsy, right kidney was hydronephrotic as a very big fluid-filled round pelvis with the presence of multilocular cysts bulged from the cortical surface. With sectioning, more than 10 L of bloody fluid poured out from this sac. Microscopic examination showed severe atrophy of cortical tissue and fibrosis of the medulla. Also, the dilated pelvis was composed of fibrinous exudate and necrosis of epithelium associated with multifocal aggregations of neutrophils and bacterial microcolonies. In a culture and serotyping of isolated bacteria, Salmonella dublin was determined. In conclusion, S. dublin induced pyelonephritis secondary to congenital giant hydronephrosis is the first report in cattle in the world

[Chemical composition and anti-candida activity of Trachyspermum ammi essential oil on azoles resistant Candida albicans isolates from oral cavity of HIV+ patients]

Oral candidiasis, caused by Candida albicans, is one of the most common infections in immunocompromised patients, especially in HIV+ individuals. The aims of this study were to evaluate the susceptibility of C. albicans isolates to azole drugs and Trachyspermum ammi essential oil. Oral swabs were cultured from 70 HIV+ patients and In order to identify and confirm of C. albicans isolates, Chrom agar, Corn meal agar, germ tube production, carbohydrate assimilation, growth at 45[degree sign]C and PCR were performed. Sensivity to fluconazol, ketoconazole and clotrimazol were assessed by disc diffusion and also the effect of T. ammi essential oil was determined by disc diffusion and microdilution broth methods. The causative agent, in 50 patients with oral candidiasis, was C. albicans [71.4%]. In sensivity determination survey to antifungal drugs, the resistance of isolates to fluconazole, ketoconazole and clotrimazole were determined 32%, 28% and 14%, respectively. In disc diffusion, all isolates have an acceptable sensivity at 10 - 20 micro L of the oil and 30 micro L inhibit the growth completely in plate. Minimum Inhibitory Concentrsation [MIC] by microdilution broth method was 500ppm and 750ppm in 72% and 28% of isolates, respectively, and Minimum Fungicidal Concentration[MFC] in 70% of isolates were 750ppm and for the rest of the isolates [30%] were 1000ppm. We conclude that use of this native plant, as an antifungal compound, could act as a treatment of the patients with mucosal candidiasis, beside of other drugs in to the future

molecular investigation of widespread Salmonella serovars, S. typhimurium and S. enteritidis, involved in salmonellosis of cattle and sheep in farms around Tehran, Iran

Salmonellosis as an important zoonotic disease that causes food born poisoning in human through animal products and is considered as a worldwide public health hazard. Widespread studies have been conducted on different aspects of incidence, treatment and control of salmonelosis all over the world

The aim of this study was to evaluate the occurrence of widespread Salmonella serovars, S. typhimurium and S. enteritidis, isolated from an outbreak of salmonelosis in cattle herds and sheep flocks around Tehran, in summer 2009, using molecular [PCR and multiplex PCR] and conventional [bacterial culture, serology and antibiogram] tests

Tissue and faecal samples were collected from 8 calves, 5 lambs and 2 aborted cattle embryos. All involved cases were animals less than 2-month-old and the presence of Salmonella serovars were confirmed in all isolates. The infection of S. enteritidis was much more prevalent in comparison to the S. typhimurium, which was statistically meaningfull [P<0.05]

Virulence gene [spv gene] of S. enteritidis was shown on 250 bp fragments in most of the organ isolates. Specifically the virulence gene was shown in all isolates of aborted fetus tissue cultures, through the molecular survey. In two calves, both S. typhimurium and S. enteritidis were detected and S. typhimurium was isolated from liver in both cases

All isolates were sensitive to streptomycin, lincospectin, enrofloxacine and trimetoprim and were resistant to doxycycline and erythromycin?

[Study in prevalence of Bartonella henselae infection in domestic cats from Tehran]

In present study the zoonotic role of cat in Bartonella henselae transmission have determined. It has done on 100 cats in 2 groups: indoor and outdoor and in 2 age's subgroups. Bartonella henselae was not isolated from blood culture of cats. 23 cats from 100 cats [23%] had antibodies against B. henselae. In this study there were no significant differences statistically in seroprevalence between cats and their owners [p<0.381]. Seroprevalence of cat owners was 18% and in control group [persons who own no cat] was 5%. There were significant differences [p<0.004] between cat owners and control group. Only 6 cats of 50 cats under 6 months old had antibodies to bartonella henselae, and in the other group 17 cats were seropositive and there were significant differences between these two groups [p<0.009] that showed seroprevalence in cats more than 6 months old is higher than the cats under 6 months old. 2 indoor cats from 50 indoor cats and 21 outdoor cats from 50 outdoor cats were seropositive and comparing of these two groups showed significant differences [p<0.0005], which confirmed indoor cats are less frequently infected than outdoor or stray cats