Infection Epidemiology and Microbiology
Year:2019 | Volume:5 | Issue:2|Papers Count:7

Objectives: Bordetella pertussis is a Gram-negative coccobacillus bacterium which is the causative agent of whooping cough. In recent years, the number of whooping cough cases has been rised. This bacterium has important virulence factors such as fimbriae and pertactin. In this study, polymorphism of Serotype 2 and 3 fimbriae genes and 2 Regions of pertactin gene were surveyed. Materials & Methods: Totally, 20 B. pertussis clinical isolates were tested. DNA was extracted using the kit. Serotypes 2 and 3 fimbriae genes and pertactin Region 1 and 2 were identified using PCR method; finally, 13 samples were randomly sequenced. Findings: No mutation was observed in the pertactin Region 2. In relation to the region1 of pertactin, %77 and %23 of the strains had prn2 and prn1 alleles, respectively. In relation to fim2 gene, %70 and %30 of the strains had fim2-2 and fim1-2 alleles, respectively. Also, in relation to fim3 gene, %70 and %30 of the strains carried fim3B and fim3A alleles, respectively. Conclusion: In general, the present study results were similar to those of the previous studies conducted in Iran, but there were some differences in fim2 gene polymorphism so that the dominant allele changed from fim1-2 to fim2-2. Considering the fact that vaccine strains of Bp134 and Bp509 carry fim3A allele, which is different from the dominant circulating allele (fim3B), it is suggested that strains more similar to the dominant circulating strains should be used in designing vaccines.

Aims: Given the prevalence of methicillin-resistant Staphylococcus aureus infections and the importance of antibiogram pattern in the treatment of these infections, the present study aimed to evaluate the methicillin and vancomycin resistant Staphylococcus aureus clinical isolates. Materials & Methods: S. aureus isolates were diagnosed using proprietary cultivation environments and standard biochemical methods by isolating 130 Staphylococcus samples from patients’ clinical specimens. The isolates antibiotic susceptibility pattern was determined by disc diffusion method. MRSA isolates were identified using cefoxitin discs, and the E-test method was used to determine the minimum inhibitory concentration (MIC) of vancomycin antibiotic. Furthermore, the multiplex PCR method was used to study the frequency of mecA and vanA genes. Results: In the present study, 57 out of 130 Staphylococcus isolates were diagnosed as S. aureus. According to the antibiogram test results, the isolates showed the highest resistance to penicillin (92. 98%) and the lowest resistance to ciprofloxacin (10. 52 %). In addition, the resistance to methicillin was reported as 21. 56 % using cefoxitin disc. According to the E-test results, 90% of the isolates were susceptible to vancomycin, and 10% showed heterogeneous resistance to vancomycin. The molecular analysis indicated that mecA gene was present in 35. 08% of the isolates, but no isolate contained vanA gene. Conclusion: Despite the lack of resistance to vancomycin, the isolates showed a high resistance to methicillin. Therefore, the present study results emphasized the necessity of performing antibiotic sensitivity tests before the drug administration.

Aim: Certain Mycoplasma species, the smallest and simplest free-living bacteria which lack a rigid cell wall, are considered as important pathogenic organisms in human and recognized to have a role in rheumatoid arthritis. The aim of this study was to use molecular methods to detect Mycoplasma spp. in synovial fluid of patients with reactive arthritis in comparison with patients suffering from non-inflammatory arthritis as a control group. Materials & Methods: Synovial fluid samples were collected from 99 patients with arthritis, all of which fulfilled the standard criteria of American College of Rheumatology for the diagnosis of inflammatory arthritis (59 patients) or non-inflammatory arthritis (40 patients). The DNA of all synovial fluid samples was extracted, and PCR was performed with a specific set of general primers for 16S rRNA of Mycoplasma genus. The PCR products were confirmed via restriction enzyme digestion using BamH1 and sequencing. Finding: A total of 11 out of 99 (11. 1%) samples of patients with reactive arthritis revealed a 270bp amplification band. Digesting the PCR product of 16S rRNA by BamH1 confirmed the PCR assay. The sequencing also confirmed the amplified products. Conclusion: The pathophysiology of inflammatory arthritis could be attributed, at least in part, to the persistence of bacterial DNA in the joint of patients with reactive arthritis.

Aim: The objective of this study was to determine the occurrence and antimicrobial resistance pattern of Staphylococcus aureus strains, as one of the important foodborne pathogens, isolated from unpacked ice creams. Materials & Methods: A total of 122 unpacked ice cream samples were randomly collected from different localities in East Azerbaijan province and transferred to the laboratory using a cool box and screened for the presence of S. aureus strains. Also, the isolates resistance to antibiotics was determined by disk diffusion method. Findings: In total, 21. 3% of the ice creams samples were contaminated with S. aureus strains. Furthermore, antibiotic susceptibility testing revealed that the highest resistance was against penicillin and erythromycin, whereas the highest susceptibility was observed against gentamicin and rifampin. A warning issue was the significant resistance to vancomycin. Conclusions: The relative high isolation and antimicrobial resistance rates detected in S. aureus strains isolated from unpacked ice creams underline the necessity for applying strict standards at all processing steps by food control agencies and emphasize the need for educational efforts for those personnel involved in products preparation procedures in order to promote food hygiene. It is worth noting that the emergence of resistance to vancomycin, as the last line of treatment for staphylococcal infections, is a worrying global health concern. Moreover, this study highlighted that poor adherence to personal hygiene and health principles during the food products preparation and/or storage could be a potential factor in the spread of pathogenic bacteria and resistance genes in the community.

Aims: The use of medications with plant origin covers a wide variety of maladies and constitutes an alternative way to antibiotic therapy, which seems to be no longer promising due to the widespread antibiotics resistance among the pathogenic microorganisms. Active principles having antimicrobial activity could be extracted and purified from plants and used in developing new medications. Among several diseases which have historically scourged man, some of the gram-negative bacteria are potentially epidemic and considered as one of the most outstanding causes of diarrhea. Therefore, this study aimed to evaluate the antibacterial activity of Thymus kotschyanus extracts. Materials & Methods: The antimicrobial effect of T. kotschyanus Boiss leaves extract on some gram-negative bacteria strains was assayed in vitro by the disk diffusion technique. Dried and crushed plant materials were extracted from distilled water by evaporation and distillation. Finally, the antimicrobial assays were carried out for the plant, and the results were compared with an ampicillin disk results. Findings: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhimurium, Entrobacter cloacae, Proteus mirabilis, and Shigella dysenteriae were apparently killed by the extract, as judged by the presence of growth inhibition halos in the assays. The results of minimum inhibitory concentrations (MICs) showed that E. coli and E. cloacae strains were better inhibited by the extract. Conclusion: The above results were similar to those from ampicillin disk, suggesting that T. kotschyanus Boiss could be used as a source of active principles against some gram-negative bacteria. Therefore, the tested Thymus extract could be considered as a valuable natural antibacterial source, which seems to be applicable in both medicine and food industry.

Introduction: Celiac disease is an autoimmune intestinal disorder which occurs in susceptible individuals by eating gluten. Not only does gluten damages the small intestine villi in celiac patients also disrupts nutrients absorption as well. People with celiac disease are unable to tolerate the gluten protein which is present in wheat, barley, oat, and possibly rye. In this study the corn sourdough lactic acid bacteria were evaluated to produce the gluten-free bread, moreover the combination of rice and corn flour were investigated whether can improve the quality and organoleptic characteristics of bread or not. Methods: In order to prepare corn sourdough lactic acid, Lactobacillus plantarum ATCC 20179 and Lactobacillus fermentum ATCC 9338 were used as starter cultures. The corn and rice flour were mixed with two different final concentrations of 5% and 10% of bacterial strains to evaluate their effects on nutritional value of breads. Physicochemical properties of breads were measured including, the moisture content; pH; Total Titratable Acidity (TTA); texture analysis; staling rate; the inhibitory activity of bacterial sourdough on bread mold growth; and organoleptic assessment of breads. All the treatments were performed independently and in triplicate. The results were statistically analyzed. Results: The organoleptic characteristics of breads were improved in breads produced by sourdough lactic acid bacteria in compare with breads produced by rice and corn flour. The pH value of rice dough containing L. plantarum was more than corn dough containing equal ratio of L. fermentum and L. plantarum. Among the samples, the acidity of dough composed of L. plantarum/L. fermentum (1: 1) was more than rice dough containing L. plantarum, corn dough containing L. fermentum. Samples with L. plantarum 10% and L. fermentum 10% showed significant differences in bread moisture compared to the other samples. For inoculated bread samples (with 5% sourdough), the required force in the third day was significantly different from the required force in the first day. Conclusion: This study confirmed the importance of fortified breads made by sourdough lactic acid bacteria (5% and 10%) with a favorable impact on sensory and rheological characteristics of bread.

Aims: Hepatitis B Virus (HBV) has infected more than million hundreds of people worldwide. Hence, a high rate of morbidity and mortality caused by liver-related diseases is due to HBV infection. However, a strong and effective treatment should be based on an accurate and correct diagnostic method. Hence, the present research provided a multidimensional study comparing and analyzing patients’ molecular and serological tests results. Materials & Methods: In this research, the HBV DNA molecular tests results were studied by examining patients’ gender, age, and HBsAg strip results. Findings: Among the female patients (29 persons) studied in this research, 55. 1% were positive for HBV DNA and HBsAg strip tests, and 17. 3% were negative for both tests. Also, among the male patients (44 persons), 65. 9% were positive, and 6. 8% were negative for both tests. Conclusion: The present study results shed light on the correlation between the HBV DNA and HBsAg tests. Also, the significance of HBV DNA tests was highlighted for particular diagnostic purposes and for the differentiation and interpretation of the pathophysiological conditions of patients with hepatitis B.