International Journal of Enteric Pathogens
Volume:1 Issue: 1, Feb 2013

Escherichia coli is usually a commensal of the digestive system, particularly intestine of humans and animals. However, there are many reports indicating that some strains are known to cause serious problems causing various infections among children worldwide, particularly in the developing countries. Escherichia coli strains can be classified into four phylogenetic groups: A, B1, B2 and D. The commensal strains are usually placed into the phylogenetic groups; A and B1 and the extraintestinal pathogenic strains into a group B2 and, to a lesser extent, group D.. The present study aimed to investigate the antibiotic resistance pattern of Escherichia coli groups A, B1, B2 and D from frozen foods and children with diarrhea.. From 125 frozen foods of animal origin and 466 rectal swabs from children with diarrhea, E. coli were isolated and identified based on standard procedures. Susceptibility testing to antibiotic was carried out according to the CLSI criteria. The phylogenetic group of each strain was determined by using multiplex PCR.. In the current study, 47 and 99 E. coli strains were isolated and allocated into four phylogenetic groups (i.e. A, B1, B2 and D). Among the strains isolated from the frozen foods of animal origin, 6.3% were allocated into phylogenetic group B2, and 23.4%% into D. Similarly, among the strains isolated from children with diarrhea 9% were allocated into group B2 and 19% to group D. The data showed that 55.3% and 53.1% of the frozen food-derived E. coli strains were resistant to Tetracycline and Amoxycillin respectively. Similarly, 89.9, 88.9 and 79.8% of isolates were resistant to tetracycline, chloramphenicol, and ampicillin, respectively. By a multiplex PCR procedure different phylogenetic E. coli were detected.. Detection of E. coli isolates is very important and shows that food of animal origin can be of a reservoir for resistant bacteria that potentially could be transferred to humans through the food chain. In addition, results of the current study also revealed the detection of resistant E. coli isolates from children with diarrhea..

Wild aquatic birds are considered as reservoir hosts for Newcastle disease viruses (NDVs) and may act as vectors for transferring these viruses to poultry, causing outbreaks of disease. Recent studies suggested that the velogenic viruses arise from avirulent strains originating from wild birds.. The primary objective of this study was to determine whether the aquatic birds of Khozestan province were infected with NDV.. In winter, 24 Muscovey ducks from Shoshtar, 20 geese from Dezfoul and 51 geese from Khorramshahr (Aquatic birds of Khozestan province) were bled, and birds'' sera were collected and used in HI assay and antibody titer to NDV were determined. Beta procedure of hemagglutination inhibition (HI) assay was performed in U-bottomed 96-well microtiter plates with 0.5% chicken erythrocytes.. All serum samples tested for antibodies against hemagglutinin by HI assay had positive results, and all of these birds had high levels of antibody titer to the NDV.. The results in the present study clearly showed that the aquatic birds of Khozestan province population in Iran carries NDVs, and may act as one of the important reservoirs for this virus. So it was concluded that detection and elimination of these birds can be a valuable tool for the control of Newcastle Disease outbreaks..

Surveillance data on Helicobacter pylori antibiotic susceptibilities are limited in Hamadan, Iran. Since antibiotic resistance is one of the reasons in therapies failure..Thus the resistance patterns of H. pylori strains to the antibiotics metronidazole, clarithromycin, amoxicillin and tetracycline were evaluated..Patients and Gastric biopsy specimens of 153 patients with nonulcer dyspepsia, peptic ulcer dyspepsia, and peptic cancer collected during May 2010 to February of 2011, and were cultured on Brucella agar (Merck, Germany) under microaerophilic conditions. H. pylori isolates were identified using standard biochemical test. Eighty three (54.2 %) specimens had positive results by culture. Antimicrobial susceptibility testing was performed by disc diffusion method.. Totally in vitro resistance rates were 63.8% for metronidazole, 26.5% for clarithromycin, and 7.2% for amoxicillin. Although, 25.3% of strains showed resistance to two antibiotics, and 3.6% to three antibiotics. Tetracycline resistance was identified in only two isolates. Fifty nine percent of the clarithromycin resistant strains also showed resistance to metronidazole. No gender and age associations with resistance were detected.. Our results showed a high incidence of metronidazole resistance (often combined with clarithromycin-resistance) in the isolates. Continuous surveillance is recommended to examine the treatment strategies for H. pylori eradication..

Phytate, the major storage form of phosphorus in plant seeds, can form insoluble complexes with minerals such as iron, zinc and calcium thus reducing their bioavailability. Phytase enzymes are often used to upgrade the nutritional quality of phytate-rich foods and feeds such as grains. The phytate-degrading activity of 43 lactic acid bacteria including isolates from commercial probiotic preparations, dairy products and type strains were measured. The phytate-degrading activity of bifidobacteria and lactobacillus isolates from pharmaceutical probiotics, dairy products and type strains were determined. The enzyme activity of probotic bacteria ranged between 1.1-5.4 mU and was strain not species specific. Phytase activity may thus be a useful additional attribute of probiotics to be used as food supplements..

Salmonellosis is one of the most common food borne diseases in industrial and developing countries. In recent years, an increase in antimicrobial drug resistance, among non-typhoid salmonella spp has been observed.. The aim of this study was to isolate and determine antibiotic resistance pattern in non-typhoid Salmonella spp.. This descriptive study was done on 100 samples of chickens collected from 196 retail markets and was examined for the presence of Salmonella using standard bacteriological procedures and stereotyping kit. Antimicrobial susceptibility testing was performed by disk diffusion methods according to the National Committee for Clinical Laboratory Standards (CLSI). The data were analyzed by using the SPSS software version 18.. Forty- four percent of samples were contaminated with Salmonella infection and 56% didn’t have any contamination. The stereotyping results showed that 34 of 44 isolates of Salmonella belonged to salmonella infantis (79.5 %), one strain (2.3%) of group C and 8 strain (18.2%) of group D. However, all these strains were sensitive to Cefotaxime and Ciprofloxacin, and 100% were resistant to Nalidixic acid, Tetracyclin and Sterptomycin. The most common resistance pattern (34.1%) was towards six antibiotics, and 6.8% of strains were resistant to at least three antibiotics.. High levels of resistance to antibiotics that are used commonly for human and poultry can be a warning for our community health and this information must be used to form important strategies for improvement of infection control..

Bloodstream infections are associated with high morbidity and mortality. Delayed etiological diagnosis and inadequate antimicrobial therapy are associated with treatment failures.. This study describes the development and assessment of a new multiplex PCR that includes an Internal Control (IC) for the assurance of the whole workflow from the extraction of the DNA until the revelation of the amplicons.. A unique sequence was chosen for each pathogen and used for primer design. Primers for amplification of Enterobacteriaceae, Enterococcus spp, Staphylococcus spp, Acinetobacter baumanii and IC were designed and tested for sensitivity and specificity on the basis of their standard strains.. The multiplex PCR showed a sensitivity ranging from 1 to 100 target copies per reaction or 50 to 100 colony forming unit (CFU) per ml to the whole blood depending on the bacterial species. The specificity of this method was elevated and no false positive amplification was identified for 17 different species other than the target microorganisms. Moreover, the detection of the IC was observed in the concentration as low as 1 copy per reaction. The correct co-amplification of IC for each single bacterial species showed a correct whole workflow procedure starting from the extraction step.. This new assay permits a rapid and accurate detection of some pathogenic microorganisms, that are among the most commonly detected ones in blood stream infections in Iran, with a simple and cost-effective method which includes the use of an internal control to validate the whole procedure thus avoiding false negative results..

Shigella is an infectious food-borne pathogen that can cause a severe diarrhea illness called shigellosis. The increasing levels of antimicrobial resistance of Shigella isolates have complicated the treatment of shigellosis. The antimicrobial resistance patterns of Shigella species vary according to geographic region and in the same place over time, leading to a therapeutic problem..This study attempts to determine the prevalence of shigellosis and the antimicrobial susceptibility pattern of isolated strains.. This cross- sectional study, with a 12-month duration, between August 2010 and August 2011 was carried out on 9131 infants with acute diarrheal disease. Stool samples were inoculated on selective and differential media. The Shigella isolates were identified and confirmed by biochemical laboratory tests. Subsequently, serotyping was performed with group specific antisera. Drug sensitivity test was carried out according to CLSI (2010) recommendations by using the standard disc diffusion method.. Shigella spp. were isolated from 90 (1%) of the 9131 stool samples collected from children with acute diarrhea. Among Shigella isolates, the most common subgroup was S. sonnei 63 (70%). Our results showed that imipenem, ciprofloxacin, ceftazidime and ceftizoxime are most effective antimicrobial agents against Shigella sp. The most frequent resistance observed, was towards co-trimoxazole (92.2%), ampicillin (65.6%) and tetracycline (65.6%).Since antibiotic resistant profile of Shigella varies geographically and also over time within a single country, regular, continuous surveillance is necessary. The results of accurate surveillance should be used to guide policies for antibiotic prescription..