Mohammad Jalali

Prevalence of Listeria species in food products in Isfahan, Iran

A total of 617 meat and meat products, diary, vegetables and ready to eat food samples were collected. Listeria spp. isolated by using USDA method of isolation and L. monocytogenes identified by biochemical and Polymerase Chain Reaction (PCR). The incidence of Listeria spp. was 4.6% in all food samples. L. monocytogenes was found in 1.2% of food samples. It was found that Listeria spp. was present in 6.7% of meat and meat product samples, 1.3% of diary samples, 1.2% of vegetable samples and 12% ready to eat samples. The results presented in this study indicate, the potential risk of eating ready to eat food or raw and undercooked foods.

Prevalence of Clostridium difficile in raw beef, cow, sheep, goat, camel and buffalo meat in Iran

BackgroundClostridium difficile has been shown to be a nosocomial pathogen associated with diarrhoea and pseudomembranous colitis in hospitalised patients and the infection is believed to be acquired nosocomially. Recent studies have shown the occurrence of C. difficile in food animals which may act as a source of infection to humans.The aim of this study was to determine the occurrence of C. difficile in retail raw beef, cow, sheep, goat, camel and buffalo meat in Iran.MethodFrom April to October 2012, a total of 660 raw meat samples from beef, cow, sheep, goat, camel and buffalo were purchased from 49 butcheries in Isfahan and Khuzestan provinces, Iran, and were evaluated for the presence of C. difficile using a method including selective enrichment in C. difficile broth, subsequent alcohol shock-treatment and plating onto C. difficile selective medium. C. difficile isolates were tested for the presence of toxin genes and were typed using PCR ribotyping.ResultsIn this study, 13 of 660 meat samples (2%) were contaminated with C. difficile. The highest prevalence of C. difficile was found in buffalo meat (9%), followed by goat meat (3.3%), beef meat (1.7%), cow (0.94%) and sheep meat (0.9%). Seven of the 13C. difficile strains (53.9%) were positive for tcdA, tcdB and cdtB toxin genes and were classified as ribotype 078. Four strains (30.8%) were positive tcdA, and tcdB, and one strain (7.7%) was possessed only tcdB. The remaining isolate was non-toxigenic. Susceptibilities of 13C. difficile isolates were determined for 11 antimicrobial drugs using the disk diffusion assay. Resistance to clindamycin, gentamycin, and nalidixic acid was the most common finding.ConclusionsTo our knowledge, the present study is the first report of the isolation of C. difficile from raw buffalo meat. This study indicates the potential importance of food, including buffalo meat, as a source of transmission of C. difficile to humans.

Clostridium difficile infection in an Iranian hospital

BackgroundClostridium difficile infection (CDI) is an important cause of morbidity and mortality internationally, yet there are important regional differences in the epidemiology and microbiology of disease. Most reports have come from North America and Europe, with limited information from other regions, including the Middle East. Given the changes in the epidemiology of CDI in developed countries, particularly associated with the dissemination of hypervirulent epidemic clones, an understanding of the epidemiology and microbiology of CDI in diverse regions is warranted. This study involved collection of stool samples from individuals with diarrhea at the Isfahan University of Medical Sciences Teaching Hospital, Isfahan, Iran, between October 2010 and March 2011. Selective enrichment culture for C. difficile was performed and isolates were characterised using ribotyping, PCR for the detection of tcdA, tcdB and cdtB genes, and tcdC sequence analysis.FindingsClostridium difficile was isolated from 19/89 (21%) stool samples of 17/86 (20%) patients. 13/17 (77%) cases of CDI were hospital-associated. Patients with CDI were significantly older (43 ± 28y) than those with non-CDI diarrhea (24, ± 26y)(P = 0.018). All isolates were toxigenic, and possessed genes encoding for toxins A and B. Six (32%) of 19 isolates also possessed cdtB. Twelve ribotypes were identified. Ribotype 078/toxinotype V was most common, accounting for 4 (21%) of isolates. A single isolate of a different toxinotype V ribotype was identified, as was a toxinotype XXIV isolate. The remaining isolates consisted of 9 different toxinotype 0 ribotypes.ConclusionsCDI is an important cause of diarrhea in patients in this hospital. The diversity of ribotypes was striking, and the number of different types suggests the presence of a broad range of strains in the community, the hospital or both. The predominance of toxinotype V strains, which have been associated with community-associated disease and food animals, was unexpected and possible sources of this type require further investigation.

Bacillus cereus in Infant Foods: Prevalence Study and Distribution of Enterotoxigenic Virulence Factors in Isfahan Province, Iran

This study was carried out in order to investigate the presences of Bacillus cereus and its enterotoxigenic genes in infant foods in Isfahan, Iran. Overall 200 infant foods with various based were collected and immediately transferred to the laboratory. All samples were culture and the genomic DNA was extracted from colonies with typical characters of Bacillus cereus. The presences of enterotoxigenic genes were investigated using the PCR technique. Eighty-four of two hundred samples (42%) were found to be contaminated with B. cereus with a ranges of 3 × 101–9.3 × 101 spore per gram sample. Totally, entFM had the highest (61.90%) incidences of enterotoxigenic genes while hblA had the lowest (13.09%) incidences of enterotoxigenic genes. Overall, 6.7% of B. cereus isolates had all studied enetrotoxigenic genes while 25.5% of B. cereus strains had all studied enetrotoxigenic genes expectance bceT gene. Thisstudyisthe first prevalence report of B. cereus and its enterotoxigenic genes in infant foods in Iran. Results showed that the infant food is one of the main sources of enterotoxigenic genes of B. cereus in Iran. Therefore, the accurate food inspection causes to reducing outbreak of diseases.

Prevalence of Listeria species in raw milk and traditional dairy products in Isfahan, Iran

Aim: The study aimed to assess the prevalence of Listeria spp. in raw milk and traditional non-pasteurized dairy products in Isfahan, Iran. Materials and Methods: A total of 292 samples of raw milk and traditional dairy were examined for the presence of Listeria spp. using a two-step selective enrichment recommended by the United States Department of Agriculture. All isolates were subjected to standard biochemical tests. L. monocytogenes strains were further confirmed by polymerase chain reaction (PCR) amplification. Results: Of 292 samples, 21 (7.14%) and 4 (1.47%) were positive for Listeria spp. and pathogenic L. monocytogenes, respectively. The prevalence of Listeria spp. in raw milk, ice cream, cream, and freni were 5.91 (5.49%), 12.63 (19.04%), 3.27 (11.11%) and 1.25 (4%), respectively. Listeria was not detected from yogurt, butter, Kashk, and cheese. Listeria innocua at 16.21 (5.44%) was the most prevalent species isolated, followed by L. monocytogenes at 4.21 (19%) and L. seeligeri at 1.21 (4.7%). All strains of L. monocytogenes identified by biochemical tests were also confirmed by PCR. Conclusion: The study shows the prevalence of L. monocytogenes in raw milk and traditional dairy products sold in the market. Consumption of raw milk with mild heat treatment or its usage in traditional dishes could pose serious health problems due to lack of appropriate control measures. The lack of knowledge on the risks of listeriosis transmission indicates the need for implementation of a food safety education program. In addition, the Iranian food safety authorities should urgently set up an effective standard to screen all susceptible food products for the presence of Listeria.

Prevalence and Characterization of Clostridium difficile in Beef and Mutton Meats of Isfahan Region, Iran

Background: Clostridium difficile (C. difficile) is a frequent cause of nosocomial infections. During last few years, the mortality rate of C. difficile infection (CDI) increased in healthcare facilities. This organism has become a major public health concern in developed nations. Because of the increasing incidence of acquired-CDI (CA-CDI) and notable genetic overlap between C. difficile isolates from animals and humans, meat has defined as one of the probable transmission route of C. diffiicle to humans. Objectives: This study was performed to determine the prevalence of toxigenic C. difficile in beef and mutton meats consumed as human food in Isfahan, central part of Iran. Furthermore the polymerase chain reaction (PCR)-ribotyping employed to compare the genetic pattern of positive isolates in meat with clinical ones. Materials and Methods: A total of 200 raw meat samples (81 beef and 119 mutton) were purchased from meat packaging plants. The samples were anaerobically cultured in C. difficile moxalactam norfloxacin (CDMN) broth and plated on selective enrichment medium. The suspicious colonies were recultured on blood agar anaerobically. All C. difficile isolates identified by morphological and biochemical testing were screened by PCR for the presence of genes encoding the triose phosphate isomerase (tpi), toxin A (tcdA), toxin B (tcdB) and binary toxin (cdtB). The genomes of extracted isolates were analyzed by 16S-23S rRNA-based PCR ribotyping. Results: The overall prevalence of C. difficile with two toxigenic genes including tcdA and tcdB was estimated at 4.0%. C. difficile was detected in 2.8%, 2.1%, 3.6% and 6.2% of chopped beef, ground beef, chopped mutton and ground mutton, respectively. The cdtB gene was not found in positive isolates. Eight different ribotypes were found in isolated strains that were not identical with those belonging to patients with CDI. Conclusions: The results of PCR-ribotyping indicate that no relationship exists between clinical and meat isolates. We therefore conclude that other sources than meat may function as a vector for CA-CDI.

Implementation of hazard analysis and critical control points in the drinking water supply system

Aims: This study was aimed to design comprehensive risk management based on hazard analysis and critical control points (HACCP) in the Isfahan drinking water system. Materials and Methods: Data obtained from field inspections and through related organizations of Isfahan, Iran. The most important risks and risky events of water quality in all sources of raw water in the study area including the Zayanderoud river, the water treatment plant, and the distribution system were identified and analyzed. Practical measures for the protection, control, and limitation of the risks in different phases, from water supply to consumption point, were presented in the form of seven principles of the HACCP system. Results: It was found that there was a potential of hazards during the treatment process of water because of seasonal changes and discharge of various pollutants. Water contamination could occur in eight identified critical control points (CCP). River water could be contaminated by rural communities on the banks of the river, by natural and sudden accidents, by subversive accidents, by incomplete operation, by lack of proportionate of the current treatment process, and by the high extent of antiquity of the Isfahan water distribution system. Conclusions: In order to provide safe drinking water, it is necessary to implement a modern risk management system such as the HACCP approach. The increasing trend of the Zayandehroud river pollution needs urgent attention. Therefore, the role of the government in developing and mandating the HACCP system in water industries is essential.

Isolation of toxigenic Clostridium difficile from ready-to-eat salads by multiplex polymerase chain reaction in Isfahan, Iran.

Background: Since 2003, the incidence of community associated Clostridium difficile infection (CA-CDI) has increased; different types of food have been supposed to be the vectors of C. difficile strains. The purpose of this study is to investigate the occurrence of C. difficile strains in ready-to-eat salads distributed in food services. Materials and Methods: A total of 106 ready-made salad specimens were sampled from different restaurants and food services located in Isfahan, in the center of Iran. Positive isolates of C. difficile were identified and confirmed for the existence of three genes including tpi, tcdA and tcdB by multiplex PCR. Results: A total of six (5.66%) samples were positive for C. difficile strains. Of which, one strain (16.6%) was positive for A and B toxins. Conclusion: The existence of toxigenic C. difficile in ready-made salads could be a caution for public health. Further investigation is required to assess the relationship between the isolated strains in our study and those from diarrheic patients through molecular typing.

Microbial quality survey of sunscreen products in Iranian market

Background: Microbial contamination of cosmetic products is very crucial because of their daily use and direct contact with the skin. These products are at high risk for microbial contamination from various sources such as environment, consumer′s hands, body sweat and during the time of manufacturing. Therefore, this study aimed to investigate the microbial quality of sunscreens products, manufactured in or imported to or formulated in local pharmacies in Iran. Materials and Methods: The microbial quality were determined in three different levels; the intact product (at the time of purchase) and after three and after six months of opening it. Total Aerobic Viable Count (TAVC) and the presence of coliforms, Pseudomonas aeruginosa, Staphylococcus aureus, molds, and yeasts were studied. Results: At the time of purchase, 40, 73.3 and 43.3 percentage of Iranian made, imported and pharmacy formulated sunscreens were contaminated with at least one of the objectionable microorganisms, respectively. After three months of opening it, 36.6, 70 and 46.6 percentage of Iranian made, imported and pharmacy formulated sunscreens were contaminated with at least one of the objectionable microorganisms, respectively. The percentages of contaminated samples were 36.6, 70 and 50 after six months of opening for Iranian made, imported and pharmacy formulated sunscreens, respectively. Conclusion: Microbial contamination of these sunscreens products is a potential health risk for consumers. It seems that it is necessary to inspect and monitor the products during the manufacturing and shelf life period. It is highly recommended to control and regulate cosmetic products by health organizations to ensure the quality and safety of this kind of products.

Antimicrobial resistance pattern of bacterial isolates from burn wounds in an Iranian University Hospital

Objective: About 73% of death cases in the first 5 days after burning are due to infection complications. The aim of this study was to identify the causing agents of infections in burn patients and the sensitivity pattern of them to the commonly used antimicrobials in an Iranian Burn center University Hospital. Methods: In this cross-sectional study, patients who were admitted to one of the Iranian Burn center University hospitals in 2009 and had nosocomial infection due to burn wound, whom received antimicrobial agents for therapeutic reasons, with a hospitalization period of more than 48 hours were enrolled. Gram stain analyses were performed to help identifying growing colonies. Differential tests for identification of pathogenic bacteria species were performed following primary tests. E-test strips of each antimicrobial were placed on the culture medium plate in order to determine the minimum inhibitory concentration Studied antimicrobials for isolated Gram-negative bacteria were meropenem, piperacillin/tazobactam, ceftriaxone, cotrimoxazole, and for Staphylococcus aureus, vancomycin, piperacillin/tazobactam, cotrimoxazole, and cephalothin. Findings: Only 16% of Pseudomonas aeruginosa species were sensitive to meropenem, and 13% were sensitive to piperacillin/tazobactam. Ten out of 29 Klebsiella species (34%) were sensitive to meropenem and piperacillin/tazobactam. All isolated strains of Staphylococcus aureus were sensitive to vancomycine while they were all resistant to cotrimoxazole. Conclusion: Pseudomona, Klebsiella and Staphylococcoci are the most common species causing burn infection in this medical center. Results showed the importance of limiting irrational use of wide-spectrum antimicrobials and recommends strict management of infections in burn injury centers.