PFGE genotyping and molecular characterization of Campylobacter spp. isolated from chicken meat

A total of 70 samples were collected from chicken meat obtained from 10 markets in Tehran, Iran from which 39 Campylobacter coli were isolated. Among 10 antibiotics used, maximum resistance was seen to trimethoprim-sulphamethoxazole [SXT] [97.36%], nalidixic acid [94.8%], ciprofloxacin [87.7%], streptomycin [89.72%], and tetracycline [97.4%]. No resistance was to gentamycin was observed. None of the Campylobacter strains under study harbored integron, suggesting the involvement of other resistance mechanisms in emergence of multi drug resistance [MDR] phenotype among the isolates. Two major types [A and B] and 15 subtypes [A1-A8 and B1-B7] were identified. Pulsed-field gel electrophoresis [PFGE] analysis demonstrated a high degree of homogeneity while the majority of the isolates shared identical or very similar PFGE genotypes. Isolates with identical genotypes differed in their resistance profile, although all of them assigned to MDR phenotype. To our knowledge, this is the first molecular survey from Iran characterizing Campylobacter isolates from poultry, which adds to our knowledge the epidemiological linkage of Campylobacter isolates with MDR properties from different sources and emphasizes the need for cautious use of antimicrobials in different fields of food production chain

[Pattern of serotyping and antibiotic resistance of Salmonella in children with diarrhea]

Gastroenteritis due to Salmonella is common in human and considered as a global dilemma of public health. This study was done to determine the Pattern of serotyping and antibiotic resistance of Salmonella in children with diarrhea in Iran. In this laboratory study, 306 stool samples were collected from children with diarrhea in public health centers in Robat-karim, Tehran province, Iran. The specimens were enriched in Selenite F medium and then cultured on Hekton agar. The identification of Salmonella was carried out by conventional method and antimicrobial susceptibility testing was performed according to CLSI procedures. Out of 306 stool samples, 7.2 % were identified as Salmonella species, as follow: 7 Salmonella typhi, 6 Salmonella paratyphi B, 3 Salmonella paratyphi C, 2 Salmonella paratyphi A and 4 samples were not identifiable. There was a significant relation between presence of WBC in fecal and salmonellosis [P<0.05]. In drug sensitivity trends, 92.3% of Salmonella species were sensitive to chloramphenicol, ceftizoxime, Nalidixic acid and Amikacin. This study showed that Salmonella was the cause of children diarrhea in 7.2% in this region

[ trend of drug resistance in toxin and non-toxin producing Shigella Spp. isolated from stool of children with diarrhea]

Diarrhea is recognized as one of the main causes of morbidity and mortality in developing countries. Gastrointestinal diseases can lead to death of many children of less than 5 years of age. The aim of this study was to evaluate the drug resistance pattern in Shigella toxin and non-toxin producing strains in children. In this descriptive analytic study a total of 80 Shigella strains, 60 strains isolated from stool samples of children with diarrhea from Loghman, Emam and Tebi Koodakan Centre Hospitals, and 20 national collection strains isolated and reserved during the last years. The isolates were evaluated for cytotoxin production by using cell culture technique [Hela cell]. Our study included 54 strains of S. flexneri, 14 strains of S.sonnei, 10 strains of S. boydii and 2 strains of S. dysenteriae. Data were analyazed by means of chi-square and Fisher's exact test. Of 80 strains 9 [11.25%] showed cytotoxic effect. Chi-square test showed no significant difference between the isolated and national collection strains [P >/= 0.05].There was no correlation between the cytotoxic activity and clinical symptoms such as abdominal pain, nausea, and frequency of passing stools / day, but other symptoms like fever and presence of blood in the stool had correlation with cytotoxin production. The results of this study showed that there was no significant difference in the antimicrobial resistance pattern between toxin and non-toxin producing Shigella strains isolated from the clinical samples and the standard national collection

[Evaluation of antibacterial properties of human amniotic membrane in vitro]

Amniotic membrane is the inner-most layer of the three fetal membranes. The membrane is consisted of three layers; epithelial layer, basal membrane, and connective tissue. Owing to expression of mRNA of elafin, HBD 1-3, and secretory leukocyte protease inhibitors, amniotic membrane has antimicrobial properties. The aim of the current study was to evaluate the in vitro antibacterial effect of human amniotic membrane on standard bacterial species of Salmonella enterica BAA-708, E.coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 7881, and Enterococcus faecalis ATCC 29212. Fresh amniotic membranes were obtained from Organ Transplant Bank of Imam Khomeini Hospital in Tehran. The membranes were obtained from pregnant women who had negative tests for HIV, HBV, HCV, and syphilis after elective Cesarian section. The membranes were cut into 1.5× 1.5 cm pieces under sterile conditions. The membrane pieces were placed on Müller-Hinton agar medium containing the bacterial suspensions and then incubated at 37 [degree sign]C for 24 hours. The antibacterial properties of amniotic membrane against Salmonella enterica and E. coli were demonstrated by development of the no growth halo, but for Pseudomonas aeruginosa only a very narrow halo was observed. The halo was not developed for Klebsiella pneumoniae and Enterococcus faecalis. Amniotic membrane showed antibacterial effects against a wide spectrum of bacteria. With regard to the increasing antibiotic resistance, use of amniotic membrane against pathogenic bacteria can be considered valuable

frequency of extended spectrum beta lactamase and CTX M-I of Escherichia coli isolated from the urine tract infection of patients by phenotypic and PCR methods in the city of Khoy in Iran

The production of Extended Spectrum Beta Lactamases [ESBLs] by Escherichia coli is the main cause of resistance to Cephalosporins. In the past decade, CTX-M enzymes have become the most prevalent ESBLs in Europe, Canada, and Asia. In this study, the frequency of ESBL- producing E.coli and molecular detection of the CTX-M-I group was investigated. A total of 400 urine samples were collected from both hospitalized and out-patients in Khoy's hospitals between November 2009 and April 2010. Out of these samples, 188 were identified as E.coli by standard biochemical tests. The antibiotic Susceptibility tests to 10 antibiotics were performed by the-disk-agar diffusion [DAD] method. ESBL production was screened by phenotypic test that including disk diffusion agar and combined disk as recommended by the Clinical and Laboratory Standards Institute [CLSI] Screened isolates were investigated by PCR assay for detection of CTX-M-I group genes. The results show that out of 188 E.coli isolates identified, 56 [29.8%] were producing ESBls by phenotypic test. All isolates were sensitive to imipenem. Overall, 49 [87.5%] isolates were confirmed as CTX-M-I producer by PCR. The results of this study showed that about 30% of the identified E.coli were producing ESBL Therefore, we recommend to use molecular methods in such researches

Evaluation of wide broad spectrum antibiotic resistance of E. coli and Klebsiella pneumonia

The Study of E.coli and Klebsiella resistance to wide spectrum antibiotics and molecular evaluation of resistance in these bacteria were examined. Treatment with wide spectrum antibiotics against bacteria can lead to resistance. The antimicrobial resistance can be seen in two types: 1] chromosomal alterations which could result in changes in structure of receptors of specific drugs. Most of this mutation can cause the absence of a penicillin binding proteins [pbps] and 2] is plasmid resistance. Plasmid genes can usually produce enzymes which result in destruction of antibiotics. An example is extended spectrum B-lactamase [ESBLs] which causes resistance to the third generation of cephalosporin, monobactams and new penicillin. ESBL plasmids are derived from TEM-1, TEM-2 and SHV-2. It has been recognized that because of point mutations in these plasmids, there are about 90 types of TEM and 25 types of SHV. The reason for the formation of point mutations within the ESBL plasmids is due to high consumption of broad spectrum antibiotics. In a cross-sectional study, 218 specimens from patients were collected and after identification of bacteria, the percentage of ESBLs among the isolates was calculated. For this purpose combined disk method and double disk method are used .Then TEM and SHV plasmids from 23 specimens of E.coli and Klebsiella were examined using plasmid extraction kit and PCR. The result of this study showed; the antibiotic resistance in 10% of E .coli was chromosomal and 50% were plasmids. The remaining isolates were sensitive. In Klebsiella, 12.8% of resistance was chromosomal and 62% were due to plasmids and remaining isolates were sensitive. The results from PCR showed; in E .coli 52.8% of the isolates were TEM positive and 84.6% were SHV positive and 69.2% were positive for both TEM and SHV. For Klebsiella 80% were TEM positive and 80% were SHV and 60% were positive for both TEM and SHV. The rate of ESBLs in Iran is higher than the results in similar studies in other countries .This could be because of the overuse of third generation of cephalosporin. For the purpose of having proper treatment using antibiotics, medical education and laboratory detection of ESBLs could be effective to choose choice antibiotics

[Analysis of poly protein processing in human parechovirus Type 1 by gene cloning and expression]

Human parechovirus is a genus of picornaviridae. All of picornaviruses have a 3C protease which has a key role in virus protein processing and replication. The aim of this study was to analyse polyprotein processing in human Parechovirus type1 by cloning and expression of 3C gene. After preparation of cDNA from human parechovirus type 1[HPEV-1] RNA genome the region of cDNA that was encoded for 3C protein was inserted into plasmid pUBS by Ligase enzyme and recombinant plasmid was prepared. After transformation and replication of this plasmid in E.coli MC 10.22, DNA was isolated by phenol extraction and then expressed in prokaryotic [E.coli BL-21] and In vitro systems under T7 promoter. The results were detected by SDS-PAGE and analyzed. The products of expression of recombinant plasmids [with out 3C gene] in both prokaryotic and in vitro systems were analyzed. Just one large band same size as primary translation product was observed, but with plasmid including 3C gene, several small bands were detected. These results indicate that human Parechovirus type1 polyprotein processing occurs by 3C protease. 3C protease was checked by anti protease. Our results showed that HPEV-1 has a processing strategy different from other members of Picornaviruses, and 3C protein seems to be the only virus encoded protease that can catalyze cleavages of all sites in the Parechovirus type1 primary polyprotein