سیامک قضایی

An opportunistic pathogen Pseudomonas aeruginosa can cause frequent hospital-acquired infections as well as one microorganism in the food spoilage. Also, the emergence of multidrug-resistant P. aeruginosa has become a serious threat to public health.This pathogen has many virulence factors which aid in bacterial invasion as well as toxicity, during infections. Out of different virulence genes in Pseudomonas aeruginosa, oprL (Encoding membrane lipoprotein L) and toxA (encoding exotoxin A i.e. ETA), are predominantly involved in, P. aeruginosa-related infections.

A total of 120 specimens of the bacteria Pseudomonas aeruginosa were collected from Veterinary microbiology and various hospital laboratories. The isolates were initially identified by culturing on MacConkey agar and Eosin Methylene blue (EMB) agar and were further characterized by morphological and biochemical tests. An antibiotic sensitivity test was carried out on 13 antibiotics using the disc diffusion method. Genotypic detection of oprL and toxA genes was performed using a specific PCR test.

The results revealed that the toxA gene was detected by 84.62% in isolates belonging to human samples and 75% in the isolates of animal samples, whereas the oprL gene was detected by 80.77% and only 16.67 % in the isolates were derived from human and animal samples, respectively.

The PCR analysis can help in the fast and specific detection of oprL and toxA genes in P. aeruginosa. Monitoring of these pathogenic genes could prevent the risk of transmission of multi-drug resistant P. aeruginosa, from animals to humans.

The aim of this study was the comparison of two protocols of estrus synchronization in two natural climates and heat stress condition on reproductive performance and concentration of plasma estrogen and progesterone hormones in Holstein dairy cows. One hundred and ten multiparous Holstein dairy cows (28 kg average daily milk yield and parity one to four calved) were randomly assigned to two protocolgroups: 1) Double-Ovsynch (DO; n=60), the cows received GnRH-7d-PGF2α-2d-GnRH and Ovsynch (GnRH-7d- PGF2α-56h-GnRH-16h- AI) was initiated 7 d later; 2) Presynch-Ovsynch (PO; n=50), the cows received PGF2α-14d-PGF2α and Ovsynch was initiated 12 d later. The both of the protocols were done in two seasons of summer and winter. The calving rate in cows that were synchronized at winter season was greater than cows synchronized in summer (36.4 vs 18.2%; P= 0.04). Mean of the number of insemination to conception was lower in cows that synchronized in winter compared to cows synchronized in summer (1.46 vs 1.74; P= 0.02). Mean of measured estrogen and progesterone hormones concentrations was higher in cows that synchronized in winter compared to summer (P < 0.05). Overall, mean of reproductive traits and hormones concentration is higher in cows that synchronized in winter than in summer and the protocol of estrus synchronization had no effect on reproductive performance.

Salmonellosis is an important zoonotic disease that the most of salmonella infection in humans result from the ingestion of contaminated food. In recent years, resistance of salmonella to commonly used antimicrobials is increasing and has emerged as a global problem. The purpose of this study was to determine the prevalence of salmonella serotypes in livestock feedstuff and their antibiotics resistance rate to antibacterial agents widely used in the Iranian health centers. To achieve this, fifty samples from livestock feedstuff were collected randomly from different parts of Ardabil city for identification of salmonella .The antibiotic resistance rate of isolates was determined using Kirby-Bauer method. Out of 50 samples examined, Salmonella was isolated from 4 samples (8%). The result of serotyping was Enteritidis (50%), Muenchen(25%) and Unknown (25%). Multiple resistance was observed among isolates. The highest resistance was to Tetracycline (100%), Sulfamethoxazole + trimethoprim (100%), Cotrimoxazole (100%), Amicycin (100%), Chloramphenicol (66.7%), Amoxicillin (66.7%), Doxycycline (33.4%), Florfenicol (33.4%) and Enrofloxacin (33.4%). All isolated were sensitive to Ciprofloxacin. The highest resistance rate was found against most prevalent drugs in poultry and animal industry, reinforcing this hypothesis that wide usage of drugs in the livestock feedstuff results in vast drug resistant bacteria.

The present study was carried out to detect Salmonella enterica in meat samples of commercial boilers (CB) and the spent hens (SH) in Ardabil, Iran. Metallo-β-lactamase (MBL) enzyme produced by Salmonella enterica strains isolated from poultry meat samples were detected by both biochemical and molecular methods. The study included 20 positive samples for Salmonella  enterica from boilers (CB) and spent hens (SH). The prevalence of Salmonella enterica for CB was 22% (11/50) and for SH was 18% (9/50). The antibiotic susceptibility testing for both CB and SH showed maximum number of Salmonella enterica isolates were resistant against Augmentin (30 μg), Cotrimaxazole (25 μg) and Tetracycline (25 μg) and susceptible against Ofloxacin (5 μg) and Gentamicin (10 μg). Screening phenotypic confirmatory test for Metallo-β-lactamase (MBL) for CB, (n= 11, 100%) were positive for MBL while for SH (n= 8, 88.88%) samples were positive for MBL. The results showed that MBL positive Salmonella enterica isolates from CB and SH meat samples contained gene blaVIM (n=11, 57.89%), blaIMP (n=6, 31.57%) and blaSPM-1(n=2, 10.52%). Since Salmonella infections in poultry are high due to large demand and antibiotic resistance to strains, so the purpose of the current study is to focus on the detection of MBL enzyme produced by Salmonella enterica isolates.

The presence of ESBLs (Extended spectrum β-lactamase) for the health system has many problems. Moreover, these strains have increased resistance to other antibiotics.The aim of this study was to determine the molecular detection of blaTEM, blaCTX and blaSHV beta-lactamase genes in Bacillus subtilis strains isolated from raw milk and cheese samples. In this laboratory study, 100 samples of raw milk and cheese were prepared and cultured. The suspicious colonies of Bacillus subtilis were identified by biochemical methods. Disc diffusion method was used to measure antibiotic susceptibility. Also, the presence of blaTEM, blaCTX and blaSHV beta-lactamase genes in ESBLs strains was evaluated by PCR (Polymerase reaction chain) method. Data were analyzed using chi-square test and reported in the form of descriptive statistics (number and percentage). The highest resistance in isolates that were able to produce the β-lactamase enzyme was related to erythromycin antibiotics (75%) and the least was related to cefotaxime (44.60%) and cefixime (46.20%) antibiotics. Of the 50 raw milk samples, TEM (Temoneira) gene was identified in 21samples, CTX (Cefotaximase) gene in 16 and SHV (Sulfhydryl-variable) gene in 3 samples. Of the 50 cheese samples, 17 (45.94%) samples contained TEM gene, 13 (35.13%) CTX gene and 2 (5.40%) SHV gene. According to the results, the use of molecular methods along with phenotypic methods seems necessary to fully recognize these types of resistance

Bacillus subtilis, a soil bacteria, Gram-positive, rod-shaped, which naturally secretes large amounts of various proteins with high concentrations into the culture medium. The aim of present study was to evaluate the phenotype detection of beta-lactamase and metalo-beta lactamase in Bacillus subtilis strains isolated from samples of milk and cheese.In this study, 100 samples of raw milk and cheese from production and distribution centers received and were cultured. Suspected Bacillus subtilis colonies were identified by biochemical methods. To measure the susceptibility was used Kirby-Bauer method, for broad-spectrum beta-lactamase enzymes and metalo-betalactamase was used Combination Disk and E-test MBL method respectively.The highest amount of resistance in isolates producing beta-lactamase enzyme was related to the antibiotic erythromycin (75%) and the lowest resistance to the antibiotic cefotaxim (44/60%) and cefixime(46/20%). The amount of resistance in isolates producing MBL enzymes was high (100%) with the exception of antibiotics cefotaxim (64/60%) and cefixime (67.40%),the lowest level resistance was observed.The results of this study show food contamination with strains resistant to the antibiotics increases the risk of transferring antibiotic resistance to intestinal bacterial flora of consumers.

Seminal plasma is a fluid with different compositions, which some of its biochemical components regulates the sperm function. The aim of this study was to evaluate the semen quality, some of the metabolites and enzymes of seminal plasma and blood serum between breeding and non-breeding season in Moghani rams. For this purpose, 8 healthy Moghani rams with 2-3 years old were used. Blood and semen samples were collected every 2 weeks in natural breeding and non-breeding seasons. Simultaneously with semen collection, scrotal circumference and testicular length as well as its volume were determined. Immediately after ejaculation, quantitative and qualitative parameters of semen and spermatozoa were evaluated, then seminal plasma was removed. Testicular volume and length, scrotal circumference, progressive spermatozoa motility, sperm concentration, live and normal spermatozoa in breeding season was significantly higher than non-breeding season (P<0.05). The seminal plasma values of triglyceride, total protein and globulin, as well as blood serum concentrations of cholesterol, triglycerides, total protein, albumin, globulin and AST were higher during breeding season compare to other seasons (P<0.05). Glucose, cholesterol, ALT, AST and ALP contents of seminal plasma and ALP concentration of blood serum were lower during the breeding season compare non-breeding seasons (P<0.05). No significant differences were observed between seasons, in the values of seminal plasma albumin and ALT in blood serum. In both seasons, there were significant differences in most metabolites and enzymes between blood serum and seminal plasma (P<0.05). Generally, testicular size, semen quality and concentrations of enzymes and metabolites in seminal plasma and blood serum have significantly differences between breeding and non-breeding seasons in Moghani ram.