Aflatoxin M1 Contamination Levels in Cheeses Sold in Isfahan Province, Iran

OBJECTIVES: Aflatoxin M1 (AFM1)-contaminated dairy products pose serious human health risks, causing liver and renal failure if consumed. They are also related to decreased milk and egg production in infected animals. This study investigated the AFM1 contamination levels in cheeses sold in Isfahan province, Iran, by enzyme-linked immunosorbent assay (ELISA). METHODS: A total of 100 white cheese samples were randomly collected from supermarkets in Isfahan province and after extraction using dichloromethane were prepared for the ELISA. RESULTS: Of the 100 samples, 52 (52%) were contaminated by AFM1, at levels ranging from 50.2 to 424.4 ng/kg. The remaining 48% of the samples had undetectable AFM1 levels (< 50 ng/kg). Based on the standard limit set by the European Commission and Iran, 8% (8/100) of the AFM1-positive samples (with concentrations between 250.2 and 424.4 ng/kg) had levels higher than the permissible value of 250 ng/kg. CONCLUSION: Although the percentage of cheese samples in Isfahan province with AFM1 levels exceeding the national permissible limit was low, the examination of cheeses and the milk used for their production is nevertheless important for ensuring public health. Furthermore, optimum storage conditions of animal feed should be ensured, and livestock nutrition must be monitored for the presence of AFM1 and other aflatoxins.

Occurrence of ambler class B Metallo-beta-lactamase gene in imipenem-resistant pseudomonas aeruginosa strains isolated from clinical samples

Metallo-beta-lactamase [MBLs] can hydrolyze a broad spectrum of beta-lactams, including penicillins, cephalosporins, and carbapenems. Genes encoding these enzymes are located on the plasmid that can easily be transferred to other bacteria. The aim of this study was to isolate and identify the Pseudomonas aeruginosa strains encoding VIM1 gene, in clinical samples, using the PCR technique. During a 4 month period, 100 strains of Pseudomonas aeruginosa from clinical specimens were collected. Standard tests were performed to identify strains of Pseudomonas aeruginosa. Resistance to antibiotics was examined and then the PCR was used to detect VIM1gene. In this study, the highest rates of resistance to antibiotics, amikacin and cefotaxime was observed [65% and 62%], the lowest resistance to antibiotics piperacillin [48%] and imipenem and cefepime with 55% resistance was reported. DDST method was performed for 37 strains for the MBl detection. Among the 37 isolate, 30 strains were MBL-producing with imipenem-EDTA method. Twelve strains [18%] were carriers of VIM1 gene using the PCR method. In the present study, the prevalence of strains producing MBL genes in strains of hospitals is a growing trend; correct prescription of medications can prevent the spread of resistant pathogens. It is suggested that molecular methods for rapid detection of resistance genes can be used to prevent the spread of this genes

Evaluation of antibacterial activity of alcoholic extract of rosemary leaves against pathogenic strains

Today, the increased use of antibiotics lead to the incidence of resistant strains. We are faced with lack of new antimicrobial drugs that have fewer side effects than antibiotics. Rosemary is a medicinal plant that has many uses in traditional medicine. In this study, ethanol leaves extract of this plant is tested on various pathogens. In this experimental study, Rosmarinus officinalis was used to evaluate the antimicrobial effects on pathogens. Ethanol extract of the leaves of this plant, with concentrations of 400, 200, 100 and 50 mg/l were prepared, and antibacterial activities were evaluated by well diffusion method on strains of Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus. Minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] was determined by the microplate method. In this study, ethanol extract of rosemary leaves at concentrations of 400 mg/ml was active against Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus aureus and Escherichia coli. Minimum inhibitory concentration of the extract on the growth of these bacteria from 6.25 mg/ml to 100 mg/ml was change. Also MBC of extract showed range from 12.5 to 200 mg/ml respectively. Result from these finding suggest that, rosemary extract, on all strains, including Staphylococcus aureus, Escherichia coli, Bacillus cereus and Pseudomonas aeruginosa, has an inhibitory effect. Also, the effect of extract, risesed by increasing the concentration

[Antibiotic susceptibility among antibiotic resistant salmonellae isolated from children [0-2 years] affected by diarrhea in Shahrekord and resistance factor transmissibility to E.Coli k12]

Background and Aim: the aim of this study was to detect the dominant serotypes of salmonellae in children and to find the antibiotic susceptibility and R-factor transmissibility among isolated salmonellae

Method: this study was conducted on 400 diarrheic stool samples collected from children in Ayatollah Kashany hospital of Shahrekord, during spring of 1999 to autumn of 2000

Results: after isolation and identification of salmonellae, seven serotypes were detected. One of them was S. typhi and other the six serotypes were S. paratyphi B. Then biogram test was performed by disk diffusion method. Best Results were taken from ceftizoxim, cephtriaxon, cephazolin and chloramphenicol. The R-factor had been transferred from isolated salmonellae to penicillin and ampicillin

Conclusion: results substanciate that unnessessary usage of antibiotics, which is the main cause of drug resistance, should be prevented