نشریه تازه ها در میکروب شناسی دامپزشکی
سال یکم شماره 2 (پاییز و زمستان 1397)

Meat is one of the perishable foods that can be contaminated and spoiled fast, if the process of production and transportation are inappropriate. Contaminated meat has been implicated in many cases of foodborne illnesses. In this study, neck, flank and rump sites of 15 beef carcasses were sampled with indirect swabbing method. Obtained Samples from final washing stage in slaughterhouse (n=45) and butcheries (n=45) were analyzed for microbial load and the effect of transportation on microbial quality were studied. In slaughterhouse, rump and neck muscles with 4.90±0.45 and 4.21±0.20 log cfu/cm2 were the highest and lowest contaminated area for Total Viable Count, respectively; but in butcheries, flank and rump with 6.16±0.25 and 5.92±0.24 log cfu/cm2 were the highest and lowest contaminated area for Total Viable Count, respectively. The most contaminated area for E coli count in slaughterhouse and butchers were rump with 1.73±0.63 and 2.14±0.06 log cfu/cm2, respectively. 26.67% and 6.67% slaughterhouse and 31.11% and 8.89% butcheries samples were positive for E. coli and Salmonella respectively. There were significant differences (p< 0.05) between the mean of Total Viable Count and E coli count of the abattoir and butcheries samples. According to the results, good hygienic practices should be used in beef slaughtering and transportation of meat.

Staphylococcus aureus is one of the most important causes of contagious mastitis in domestic animals. Due to the existence of multiple strains of S. aureus and strain variations in chromosomal allelic rearrangement, different genotyping methods, such as analysis of the chromosomal DNA following the enzymatic digestion, are introduced for genetic typing of the bacterium. In the present survey, for the first time, the genetic diversity of S. aureus recovered from clinical bovine mastitis in Sanandaj was investigated based on PCR-RFLP analysis of the aroA gene. 120 bovine mastitic milk samples were collected aseptically and assessed. S. aureus isolated in culture and routine bacteriological methods were analyzed by aroA gene-based PCR. The amplicons with a size of 1153bp were digested with TaqI restriction enzyme and the fragments were electrophoresed. 28 S. aureus strains were isolated in phenotypic method among which the expected amplicon was observed in all of them. In enzymatic digestion, two RFLP patterns, nomenclatural based on the previous studies were generated. Genotype B was detected in 23 (82.14%) isolates and genotype N in 5 isolates (17.85%). The results demonstrate that S. aureus is involved in bovine mastitis in Sanandaj and despite the presence of limited genotypes, strain variation of this bacterium exist in the region. The presence of genotype B in all farms implies the same source of infection among farms, which should be considered in control programs of mastitis. Non-detection of universal genotype A and specific genotype of the bacterium in Sanandaj is reported for the first time.

The zoonotic bacteria, Streptococcus iniae is the causative agent of streptococcosis associated with serious economic losses in the word aquaculture industry. The antimicrobial activities of Thymus vulgaris, Carum carvi, and Menthalong flora essential oils were determined against two pathogenic isolates of S. iniae using broth microdilution, and were compared with erythromycin and enrofloxacin antibiotics by disk diffusion assay. Also, bacterial growth was followed by OD at 600 nm. The minimum inhibitory concentration (MIC) of the T. vulgaris, C. carvi, and M. flora essential oils were 0.8, 0.8, and 0.8-1.6 μl/ml, and the minimum bactericidal concentration (MBC) values were found as 0.8, 1.6, and 1.6 μl/ml, respectively. Moreover, the growth of isolates was reduced by increasing essential oils concentration. Also, disk diffusion assay revealed that the antimicrobial activity of T. vulgaris essential oil is significantly higher than the other plants, as well as erythromycin and enrofloxacin antibiotics. These findings support the use of T. vulgaris for the control of streptococcosis in trout farms.

Staphylococcus aureus is a gram positive Bactria which has been considered as one of the most common agent of food bacterial poisoning and also considered as a zoonotic disease. Therefore, the aim of the current study was to isolate of different strains of S. aureus from nasal samples of sheep from Sistan region and evaluation of antibiotic resistance of the isolated bacteria against common antibiotics. Moreover, the antibacterial activity of ethanol, methanol and ethyl acetate extracts of Teucrium polium plant on S. aureus was assessed. The plant samples were gathered from Sistan Region. Ethanol extract of plant samples was extracted using vacuum from the center (rotary) apparatus. A total number of 10 S. aureus strains were isolated from the sheep nasal samples from Sistan region. Susceptibility to Oxacillin, Amoxicillin-clavulanic acid, ampicillin, Gentamicin, Cefazolin and Vancomycin antibiotics was evaluated by the Kirby-Bauer disk diffusion standard method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of different concentrations of plant extract were determined on bacteria using dilution in well method. Results of the current study explained that all of the three ethanol, methanol and ethyl acetate extracts had various bactericidal levels on 12 isolated bacteria. Nevertheless, the ethyl acetate extract was batter than two other extracts due to its lower concentrations for its MIC and MBC against S. aureus. Results derived from the current study suggest that ethyl acetate extract of T. polium would be a suitable alternative for common antibiotics.

Coccidiosis is one of the most important parasitic diseases in the poultry industry, which is caused by the Eimeria and Cryptosporidic species. The main goal of current study was to investigate the prevalence of different Eimeria species in indigenous poultry of Behbahan, Khuzestan province, south west Iran. Fecal samples were collected randomly in all of the 100 native birds from 11 villages in this region. Number of oocysts per gram of faeces (OPG) was determined by the standard McMaster technique. Identification of oocysts was done on sporulation in 2.5 % potassium dichromate solution. The results showed an overall prevalence of 20% for Eimeria sp. Infection Contains 15%; E. acervulina (80%), E. maxima (60%), E. brunetti (53.3%), E. tenella (33.3%) and E. mitis (26.6%) with mixed infections of E. maxima +E. acervulina (40%), E. tenella+E. brunetti +E. maxima (46.6%), and E. brunetti +E. maxima + E. tenella (2.2%) +E. mitis (13.2%) were determined. In order to determine the rate of Cryptosporidium infection, the samples were first stabilized using 70% methanol and stained under the Modified Zeheil Neelsen method. They were examined using an optical microscope. From the obtained spreads, 8 samples (8%) have been recognized as positive. This is the first report of coccidiosis in native birds in this region.This diseases may be an important factors in the economic losses of the native and broiler chickens in this region.Further additional research and design control strategies for improving management farms are necessary.

Ostrich meat has a high nutritional value, and in addition has low levels of cholesterol and fat, and also unsaturated fats and Omega 3 in this meat is higher than beef and sheep. Due to the rapid reduction in pH of ostrich meat after slaughter (compared to red meat) and reduced storage time, the risk of microbial growth in this product is important. In this study, 20 healthy ostriches with age range of 10 to 14 months, that all cultivated on a same farm, were selected and 10 pieces by traditional method and 10 pieces by industrial method were slaughtered. Microbiological characteristics (counting of psychrotrophic, mesophilic aerobic bacteria, staphylococcus areues and coliform, and identification of E. coli and salmonella) and chemical (protein, fat, moisture and ash) measurements were analyzed.Rresults were compared by using independent T-test statistics method between two groups of traditional and industrial ostrich carcasses. According to the results, the amount of microbial count in all microbial parameters in traditional slaughtering group was higher than industrial group (p0.05). Therefore, it is recommended that ostrich slaughtering be carried out in industrial slaughterhouses and with the principles of hygienic packaging so that this product can be provided under better sanitation conditions for supply to consumers.

Environmental mastitis has been increased significantly in recent years due to control of contagious mastitis agents. Marbofloxacin is an antibiotic which is the derivatives of Carboxylic acid, the third generation of Fluoroquinolone. It has antibacterial activity against gram negative and positive bacterial. The aim of this study was the comparative effects of two injectable solutions of Marbofloxacin manufactured by 2 European companies on environmental mastitis due to E. Coli. Milk samples were taken from 86 with clinical mastitis dairy cows and cultured. Fifty cows contaminated with E.coli and treated after diagnosis. Animals stratified to two groups, treatment and control. The treatment group animals (N. 25) were taken injectable antibiotic solution of Marbofloxacin manufactured by a Belgian company, 2mg/Kg, (1ml/50Kg body weight) IM for 3 days. The control group animals (N.= 25) were taken injectable antibiotic solution of Marbofloxacin manufactured by a French company 2mg/Kg, (1ml/50Kg body weight) IM for 3 days. The animals in treatment and control groups were cured 40% and 53%, respectively. There were no significant differences using chi-square statistical method (P>0.05). It is concluded that Marbofloxacincan of both companies are affected on mastitis due to E.Coli.

Among diseases caused by Escherichia coli, there is a severe systemic form termed colisepticaemia, which is characterized by the presence of E. coli in the blood, and colonization of organs including the heart, liver and spleen. The aim of the present study was to investigate different phylogenetic groups of E. coli isolated from broiler breeder with colibacillosis in Urmia. In this study, eighty swabs collected from liver and lung were cultured on MacConkey agar plates. Pink color colonies were isolated and confirmed as E.coli by biochemical tests and followed by multiplex-PCR to identify different phylogenetic groups. Out of 80 samples 21 isolates were identified as E.coli. Eight of isolates (38%) were belong to group A, 2 of them (9.5%) were belong to group B1, 6 of them (28.6%) were belong to group B2 and 5 of them (23.8%) were belong to group D2. According to the results of present study different phylogenetic group were observed in breeder herds. Most of them were classified as group A which is commensal. Studies showed that pathogenic E.coli has a considerable antibiotic resistance rate which might be transmitted to broilers in different ways and poses economic constraint to poultry industry. Thus, important strides must be made on eradication of different pathogenic E.coli.

Escherichia coli is the most abundant bacterium that causes urinary tract infections. The E. coli strains that cause urinary tract infections, known as "Uropathogenic E.coli (UPEC)", contain various virulence factors. According to previous studies, the strains belonging to the phylogenetic group B2 are the most important strains, whereas strains of group A are the least effective strains for causing urinary tract infections. In this study, 100 samples of E. coli isolated from patients with urinary tract infection were confirmed by standard biochemical methods. After extraction of genomic DNA, 72 strains (55 strains belonging to phylogenetic group B2 and 17 samples belonging to group A) were selected by Triplex-PCR method to determine the distribution of virulence genes. The frequency of virulence genes cnf1, irp2, iha and ompT were observed to be 38.88%, 29.16%, 91.66% and 77.77%, respectively. The frequency of these genes in phylogenetic group B2 was significantly higher than group A. Significant difference was observed in the distribution of cnf1 and irp2 genes in both phylogenetic groups B2 and A (P≤0.05). In terms of gene distribution pattern, 10 unique patterns (Ec1-Ec10) were observed for these two groups. The results of this study showed that strains B2 contain more virulent genes than strains A and may have an important role in the development of urinary tract infections.

Abortion is one of the problems of sheep and goats breeders in Iran and imposes significant economic losses on farmers. Infectious agents are the most common reason for abortion in sheep and goats. Some of these agents, such as Brucella and Toxoplasma, Leading to zoonotic diseases. Regarding the important role of sheep and goat breeding in livelihood of the people, it is very important in terms of economics and public health, to accurately know the abortive infectious agents in sheep and goat flocks.The purpose of this study was to investigate all the literature which attempts to diagnose Bacterial, viral and protozoan agents of sheep and goat abortion in Iran. Therefore, all articles related to abortion of sheep and goats, individual infectious agents and their prevalence in the geographical area of Iran or neighboring countries, were included in databases including Science Direct, Pub Med, Scopus, Google scholar , Magiran and Iran doc were searched. Of the English and Persian studies found, 36 studies were conducted on abortion of sheep and goats that their results inserted in a table for better evaluation. Based on studies that examined the causes of abortion of sheep and goats in different provinces of Iran, Brucella, Toxoplasma, Chlamydophila, Campylobacter and Salmonella are the most common causes of abortion in the country. No study has tracked the viral agents in abortion of sheep and goats in Iran.