فهرست مطالب
International Journal of Enteric Pathogens
Volume:8 Issue: 2, May 2020
- تاریخ انتشار: 1399/10/27
- تعداد عناوین: 8
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Pages 39-43Background
Uropathogenic Escherichia coli (UPEC) is one of the most common etiologic agent of urinary tract infection (UTI). The ability of Escherichia coli to cause UTI is associated with specific virulence determinants, which are encoded by pathogenicity islands (PAIs).
ObjectivesThis study aimed to investigate the distribution of PAIs among the UPEC isolates collected from patients with UTIs.
Materials and MethodsIn this study, a total of 100 E. coli isolates were collected from patients with UTIs using standard microbiological methods. Polymerase chain reaction (PCR) was used for the identification of the main PAIs of UPEC according to insertion sites and virulence markers.
ResultsIn total, PAI IV536, PAI III536, PAI I536, PAI, IICFT073, PAI ICFT073, PAI IIJ96, PAI II536, and PAI IJ96 were detected in 23, 22, 17, 17, 13, 11, 11, and 8% of isolates. PAI combinations were identified in 15% of isolates.
ConclusionThe results showed that PAIs of UPEC are not strain-specific and some strains can carry the PAIs associated with the prototype strains of UPEC simultaneously
Keywords: Pathogenicity island, Insertion site, Urinary tractinfections, UropathogenicEscherichia coli -
Pages 44-50Background
Several occurrences of infections and intoxications have been globally announced as a result of the Escherichia coli contamination of foodstuffs. In addition, the emergence of antibiotic resistance in different geneses of bacteria is becoming a major concern for public/ medical health authorities and researchers.
ObjectiveAccordingly, this study determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the essential oil (EO) nanoemulsion (NEO) of Zataria multiflora Boiss against E. coli. Finally, different sub-MIC concentrations of the NEO of zataria EO on the growth rate and the gene expression of stx1A and stx2A were investigated as well.
Materials and MethodsOil in water NEO was formed by the phase inversion technique. The mean diameter of droplets and the zeta potential of NEO were determined, and then the MIC and MBC of EO and NEO were estimated using the broth microdilution method. Eventually, the growth rate and expressions of the stx1A and stx2A genes of E. coli were evaluated after exposure to various sub-MICs.
ResultsBased on the results, carvacrol was the main constituent of the EO, and NEO droplets had an average size of 61.5 nm and a zeta potential of -27 mV. Further, the MIC values of EO and NEO were 0.45 ± 0.17 and 0.25 ± 0.10 mg/mL, and their MBCs were found 0.55 ± 0.20 and 0.30 ± 0.05 mg/mL, respectively. Furthermore, NEO expressed a stronger inhibitory effect against E. coli growth compared to pure EO. At 75% MIC of EO, the transcriptional rate of stx1A and stx2A decreased 2.24 and 2.66 times at the end of the 72-hour period compared with the control, respectively. After 72 hours, treatment with 75% MIC of NEO resulted in the downregulation of stx1A and stx2A as 4.75 and 4.80 fold, respectively.
ConclusionThe greater activity of the NEO of Z. multiflora Boiss. in comparison with pure EO for slowing down the growth of E. coli and Shiga toxin production shows its potential as a novel ‘green’ food-grade preservative.
Keywords: E. coli, Geneexpression, Nanoemulsion, Shiga toxin, Zataria -
Pages 51-54Background
There are different methods for genomic DNA extraction. Magnetic nanoparticles (MNPs) exhibit many important features making them suitable for DNA extraction.
ObjectivesThe aim of this study was to compare the effect of monolayer and bilayer MNPs on genomic DNA extraction.
Materials and MethodsThe genomic DNA was extracted from the Staphylococcus aureus strain ATCC 25923 and clinical isolates using monolayer MNPs SiO2 and Fe3 O4 and bilayer MNPs SiO2 /Fe3 O4 . Then, the quality and quantity of the obtained genomic DNA were compared with both NPs.
ResultsThe obtained results showed the concentration and purity of the extracted genomic DNA using bilayer magnetic NPs was significantly higher in comparison to the extracted genomic DNA by monolayer MNPs.
ConclusionIn general, surface-coated MNPs are much more efficient than naked MNPs for genomic DNA extraction.
Keywords: Magnetic nanoparticles, Staphylococcus aureus, Genomic DNA, DNA extraction -
Pages 55-59Background and Objectives
Consuming raw or undercooked cattle meat is the most common transmission way of infection with Escherichia coli O157:H7. The present study aimed to identify virulence genes stx1, stx2, hlyA, and eaeA in E. coli isolated from meat samples (beef and mutton) in Hamedan during 2015 and 2016.
Materials and MethodsFor this purpose, the swabs were randomly taken from 160 meat samples including 80 beef samples and 80 mutton samples from butcher shops. Isolation and identification of E. coli cells were conducted by culturing the swab samples on MacConkey agar and Eosin methylene blue agar media. Then, the identity of the suspected E. coli O157:H7 colonies was investigated by a multiplex PCR assay and eventually, the isolates were evaluated for the presence of stx1, stx2, hlyA, eaeA virulence genes.
ResultsThe results showed that out of 160 cultured samples on the selective media, 60 samples (37.5%) were contaminated with E. coli. O157:H7, O157, and H7 strains were identified using PCR, among which only E. coli O157:H7 possessed all four virulence factor encoding genes.
ConclusionThe results of this study showed that beef could be a reservoir for E. coli O157:H7, and it may be involved in the transmission of this pathogen to humans.
Keywords: E. coli O157:H7, Meat, PCR, Virulencefactors -
Pages 60-65Background
F Campylobacter species are imperative foodborne bacteria because of the contaminated poultry meat consumption.
ObjectivesThis study was conducted to recognize the incidence and antimicrobial resistance profile of Campylobacter species recovered from raw poultry meat samples.
Materials and MethodsA total of 695 poultry meat samples were collected and assessed by culture technique. Bacterial species were identified by polymerase chain reaction (PCR). Antimicrobial resistance was assessed by disk diffusion method (DDM).
ResultsThe contamination rate of samples with Campylobacter spp. was 44.75% with higher contamination rate of wild duck (84%), wild goose (83.33%), coot (78.26%), chicken (67.78%), and wild pheasant (66.66%), respectively. Campylobacter jejuni and C. coli bacteria were found in 84.24% and 15.76% of Campylobacter spp., respectively. The highest incidence of C. jejuni was obtained in partridge (95.45%), quail (95%), pheasant (92.31%), and wild duck (90.48%) meat samples, respectively. The highest incidence of C. coli was found in turkey (52.63%) and wild pheasant (22.22%) meat samples, respectively. Moreover, C. jejuni had the highest resistance to tetracycline (76.34%), nalidixic acid (65.65%), ciprofloxacin (58.78%), enrofloxacin (39.69%), and ampicillin (38.55%), respectively. C. coli had the highest resistance to nalidixic acid (48.99%), ciprofloxacin (40.82%), and enrofloxacin (38.78%), respectively.
ConclusionPoultry meat, particularly partridge, quail, pheasant, turkey, and wild avian are the main sources of Campylobacter transmission. Furthermore, higher incidence and antibiotic resistance of C. jejuni was found. Proper cooking of poultry meat and monitoring the antibiotic prescription can lessen the occurrence of antibiotic-resistant Campylobacter spp. in poultry meat
Keywords: Campylobacterjejuni, Campylobactercoli, Antibiotic resistance, Poultry meat -
Pages 66-72Background
Rotavirus (RV) is one of the most important causes of diarrhea in the calf and human neonates. Rotaviruses are divided into nine different serogroups, of which group A is more important compared to other groups.
ObjectiveThis study was performed because of the lack of information about the importance and prevalence of bovine rotaviruses B (RVB) and C (RVC) and human genotypes of rotavirus A (RVA) in the bovine population in Iran. Phylogenetic analysis of VP6 of bovine RVA was the second aim of the present study.
Materials and MethodsA total of 581 stool specimens were collected from diarrheic calves of 14 provinces and were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and 485 of them were investigated by PAGE electrophoresis to determine the frequency of three rotaviruses A (RVA), B (RVB), and C (RVC). The presence of human G and P genotypes in Iranian bovine population was also evaluated using semi-nested multiplex RT-PCR.
ResultsRVA was detected by RT-PCR (VP6 gene detection) in 16.2% (94/581) and by PAGE in 22.16% (108/485) and no positive cases of RVB and RVC were confirmed by polyacrylamide gel electrophoresis (PAGE). This study showed that non-A RV groups (B and C) have little role in calf diarrhea in Iran. The results of the phylogenetic study of VP6 sequences of rotaviruses A identified in this study showed that they all belonged to genotype I2 and were classified into three different branches. Specimen isolated in Zanjan showed the highest difference (maximum identity of 94%) with other sequences and clustered along with the Japanese strain, R22. Human G and P genotypes were not found in the studied samples.
ConclusionThe results showed that non-A rotaviruses and human genotypes of RVA are of little importance in calf rotavirus diarrhea in Iran. Also, there is the first phylogenetic study of rotavirus A VP6 protein in Iran.
Keywords: Rotaviruses A, Rotaviruses B, RotavirusesC, VP6 gene, Phylogeneticanalysis, Genotyping -
Pages 73-74
Infant botulism is an uncommon disease with a challenging diagnosis which is often confused with other diseases. This is a report of a case of infant botulism with no history of honey ingestion and responds well to equine immunoglobulin due to the low prevalence and importance of the mentioned disease
Keywords: Infantile botulism, Clostridium botulinum, Honey ingestion