Infection Epidemiology and Microbiology
Year:2017 | Volume:3 | Issue:4|Papers Count:8

Background: Escherichia coli (E. coli) strains are among predominant agents causing nosocomial and community acquired infections. The majority of strains encode numerous virulence factors including fimbrial adhesions, secretory proteins and toxins, siderophores, and capsule. This study aimed to investigate the prevalence rate of virulence encoding genes and carbapenem resistance-encoding genes among imipenemresistant E. coli isolates collected from patients hospitalized in Tehran, IR Iran. Materials and Methods: In this cross-sectional study (April 2015-December 2017), 50 non-duplicated carbapenem-resistant E. coli isolates were collected from clinical specimens (stool, urine, blood, and wound) of hospitalized patients in three hospitals in Tehran, Iran. The antibiotic susceptibility profile was determined against 15 antibiotics on Mueller Hinton Agar (MHA) as per CLSI guidelines version 2016. The PCR was used to detect virulence and antibiotic resistance encoding genes. Results: From a total of 50 carbapenem-resistant E. coli isolates, the highest resistance rate was observed to ceftazidime (100%), tetracycline (88%), amoxicillin (100%), sulfonamide (60%), and the least resistance rate was observed against amikacin (14%), gentamicin (22%), and fosfomycin (0%). The genes mediating resistance were as follows: beta-lactams OXA-48 (8%), IMP (16%), VIM (0%), NDM-1 (0%), fosA3 (0%), quinolones (qnrA 48%), and colistin mcr-1(0%). Furthermore, the prevalence rates of of fimA, hlyA, cnf1, vat, pic, crl, and papH were 88, 36, 28, 10, 12, 54, and 88%, respectively. Conclusion: In this study, all imipenem-resistant E. coli isolates were susceptible to fosfomycin, and all were fosA3 negative. Among carbapenemase genes, IMP and OXA-48 type enzymes associated with higher MIC levels (8 to 32 μ g. mL-1) were detected. In this study, data suggest the role of these carbapenemases in resistance to carbapenems. Furthermore, the presence of multiple drug resistant strains encoding adhesive and secretory virulence factors is a concern for the infections treatment.

Background: Klebsiella pneumoniae is a Gram-negative bacterium and as a part of the natural microflora in human body gastrointestinal tract. K. pneumoniae has been known as one of the most common causes of nosocomial infections and multi-drug resistance pathogens. The aim of this study was to examine antimicrobial susceptibility and genetic relatedness among K. pneumoniae strains isolated from hospitals in Borujerd city in western Iran using Enterobacterial Repetitive Intergenic Consensus (ERIC)– PCR technique. Materials and Methods: A total of 100 K. pneumonia isolates were collected from Borujerd hospitals during April to September 2015. After detection and confirmation of K. pneumonia isolates by conventional laboratory methods and differential tests, antibiotic susceptibility testing was performed using disk diffusion method. Also, genetic relatedness of 35 selected MDR K. pneumonia isolates was examined by ERIC-PCR technique. Results: Antibiotic susceptibility testing showed that among K. pneumonia isolates, the highest antibiotic resistance was to ampicillin (91%), and the highest susceptibility was to imipenem (5 %). More than 45% of the isolates showed multi resistant phenotypes. Based on ERIC-PCR results and data analysis, 32 different ERIC types. Conclusion: The results of this study indicate the increase in multi resistant K. pneumoniae in hospitals under study. The results of ERIC PCR showed the high genetic diversity among K. pneumoniae strains, indicating the polyclonal distribution of K. pneumoniae isolates in Borujerd hospitals.

Background: Enterococci play an important role in the spread of drug resistant genes and thus resistant strains. The dissemination of vancomycin-resistant Enterococci (VRE) strains is one of the crucial issues in hospitals worldwide, especially among those hospitalized patients. This study aimed to assess the antibiotic resistance pattern and the prevalence rates of vanA, vanB, and vanC genes among Enterococcus faecalis strains isolated from meat. Materials and Methods: This cross-sectional study was performed on 181 isolates of E. faecalis isolated from consumed meat samples in Borujerd city. Antibiotic susceptibility testing was performed using the disk diffusion method according to CLSI criteria. The prevalence rate of vanA and vanB genes in vancomycin resistant E. faecalis strains was identify by PCR technique. Results: Of 181 Enterococci isolates, 100 strains (55. 25%) were E. faesium, and 81 strains (44. 75%) were E. faecalis. About 13 antibiotics were used in this study. The highest resistance was observed against erythromycin, linezolid, vancomycin, and penicillin antibiotics, and the lowest resistance was observed against meropenem; none of the isolates were resistant to nitrofurantoin and cefotaxime. A total of 68 isolates (83. 95%) were resistant to vancomycin. Among the isolates, 38 isolates (46. 9%) contained vanA gene, 21 isolates (25. 9%) carried vanB gene, and 18 (22. 2%) isolates contained vanA and vanB genes, but van C type was not detected in none of the isolates. Conclusion: The presence of van gene in the majority of isolates is an indicator of resistant genes large reservoir in the strains rotation in the community. Furthermore, in order to limit the incidence of VRE, the use of antibiotics for human or animal should be taken with caution.

Background: Emergence of drug-resistant bacteria has highlighted the need to identify new and more efficient antibacterial agents. The aims of this study were to evaluate the antibacterial activity of dill (Anethum graveolens) seeds essential oil and to investigate the effect of cumin (Cuminum cyminum) seeds alcoholic extract on biofilm formation ability of Klebsiella pneumoniae. Materials and methods: This experimental study was carried out at the Faculty of Medicine of Kurdistan University of Medical Sciences in 2014. Activity of dill seeds essential oil was evaluated based on the inhibition zone diameter and minimum inhibitory concentration (MIC) against some important pathogenic bacteria including: Vibrio cholerae, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Furthermore, the effect of sub-inhibitory concentrations of cumin seeds alcoholic extract was evaluated on biofilm formation ability of K. pneumoniae. The biofilms were formed on semi-glass lamellas and observed by a scanning electron microscope. Results: Dill essential oil showed a good to moderate activity against the tested strains. The highest antibacterial activity was observed against S. aureus (inhibition zone of 15 mm and MIC of 0. 62 mg. mL-1) and V. cholerae (inhibition zone of 14 mm and MIC of 0. 7 mg. . mL-1). The cumin alcoholic extract had no effect on biofilm formation ability of K. pneumoniae. Conclusion: The results of this study showed the presence of antimicrobial compounds in dill extract. The cumin alcoholic extract was not able to inhibit biofilm formation ability of K. pneumoniae. Because of the medicinal plants properties, it is valuable to search for promising herbs and novel chemical compounds.

Background: In recent years, the presence of large amount of research isolating and detecting Arcobacter spp. from animals and humans with diarrhea and from food samples highlights the importance of Arcobacter spp. as emerging food-borne pathogens worldwide. Recently, independent studies have been conducted, making significant progress in the understanding of the classification and pathogenicity of this group of microorganisms. However, the incidence of Arcobacter infection is likely to be underestimated mainly due to the limitations in current detection and identification methods. This study was done to evaluate the effectiveness of staining method (Gram stain using 1% fuchsine in direct smear) versus PCR as the gold standard. Materials and Methods: A total of 150 stool samples were collected from under 6 years of age children with diarrhea from clinical centers of Arak. Direct smears of samples were stained with a modified gram staining method (1% fuchsine for 5 minutes with heat). Concurrently, PCR amplification method was performed for all DNA samples. Results: Arcobacter spp. was isolated by PCR from 28 out of 150 stool samples. Direct staining method identified 79 samples as Campylobacter-like organisms with a sensitivity and specificity values of 100 and 65. 50%, respectively. Conclusion: Detection of Campylobacter-like organisms by 1% fuchsine is simple, inexpensive, and fast with high sensitivity and specificity. Laboratories with limited resources can employ modified gram staining method to detect Campylobacteriaceae infection in early stages.

Background: Enterobious vermicularis (E. vermicularis) is one the most common parasitic infection among children. The present study aimed to determine the prevalence rate of enterobiasis among preschool children in Mazandaran province, northern Iran. Materials and Methods: In this cross– sectional study, 653 preschool children were recruited via the cluster sampling method during April 2013 to Feb 2014. A questionnaire was administrated to parents by an interviewer and determined children’ s socio-demographic characteristics, personal hygiene, and healthy behaviors. The Graham technique was applied for diagnosis. Data were analyzed using logistic regression model and chi-square test. Results: In a total of 653 examined subjects, the prevalence rate of E. vermicularis was 19. 4%, among which 40. 9% were male, and 59. 1% were female. The highest and lowest prevalence rates of E. vermicularis were found in Neka (61. 4%) and Tonekabon (1. 6%) districts, respectively. A significant association was found between infection and residency, parental occupations, parental education, number of family members, changing underwear, sterilization of linen clothing, taking daily bath, boiling or ironing clothes. Conclusions: The high prevalence rate of E. vermicularis infection in this study proves the stability status of enterobiasis in this area, posing a risk for children there. Systematic control of infection in children is proposed.

Background: Parasitic infections can cause different chemical changes in human body. This study was designed to determine the liver aminotransferase changes in Iranian people infected by parasite. Materials and Methods: In this cross-sectional study, blood samples were collected from 183 parasite-infected patients. After serum isolation in laboratory, Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) rates of all samples were measured according to IFCC standard method, and after recording in the information form, the results were analyzed using descriptive statistics. Results: The results of this study showed that patients were infected by 19 different types of parasites. Also, the results showed that the average value of ALT and AST in patients were equal to 32. 30 ± 23. 40 and 38. 60± 34. 80, respectively. The ANOVA test showed remarkable statistical differences between these values and various infections. There was positive and significant correlation between ALT and AST. Conclusion: The abnormality in liver function in patients with eosinophilia can be caused by parasitic infections in endemic areas; therefore, it can be the cause of a differential diagnosis for physicians. Generally, non-significant changes in transaminase levels can also be attributed to the infection low intensity in patients tested.

Background: Nocardia as a Gram-positive bacillus with a microscopic appearance of branching hyphae can produce considerable disease in an appropriable host. N. facinica is a member of genus Nocardia that is potentially life threatening; therefore, therapy of N. farcinica infection remains difficult. Case presentation: This study is a case report of disseminated N. farcinica infection in a 64-year-old man with a history of pneumoconiosis with brain, lung, and skin involvement in Labbafi Nejad hospital, Tehran, IR Iran in November 2013 with a discussion about diagnosis and management of this particular patient. Conclusion: Due to the involvement of brain, triple therapy was started with meropenem, amikacin, and linezolid.