Infection Epidemiology and Microbiology
Year:2017 | Volume:3 | Issue:1|Papers Count:8

Background: Pseudomonas aeruginosa is one of the main causes of nosocomial infections with a mortality rate up to 40-50%. Resistance to antibiotics is a global challenge in the treatment of infections caused by this bacterium. The Class A beta-lactamases genes, including blaSHV, blaPER, blaVEB, are the most common causes of resistance in this microorganism. This study was conducted to determine antibiotic resistance pattern and the presence of blaper, blaveb, blashv and blaoxa-10 genes in clinical isolates of P. aeruginosa isolated from patients in a hospital in Bandar Abbas. Materials and Methods: This cross-sectional study was conducted on 72 P. aeruginosa clinical isolates. Antibiotic susceptibility testing was performed by disk diffusion method according to the clinical Laboratory Standard Institute. MIC (Minimum inhibitory concentration) of ceftazidime was performed by E-Test. Polymerase chain reaction (PCR) was performed to identify blashv, blaveb-1, blaoxa-10, and blaper-1 genes. Results: Most of the isolates were detected from intensive care unit and urine samples. The highest resistance rate which was observed to sulfamethoxazole and ceftazidime, were 68 (94. 44%) and 44 (61. 11%), respectively. About 27. 8% of these isolates were multidrug resistant. Among 44 ceftazidime resistant isolates, 15 isolates (34%) showed MIC ≥ 32 μ g. mL in the E-test. The prevalence rates of genes were 4. 16, 12. 5, 8. 33, and 1. 38% for blaOxa-10, blaShv, blaVeb-1, and blaPer-1 genes, respectively. Conclusion: The ceftazidime resistance rate and the prevalence rate of resistance genes in the present study were lower than other Iranian studies. However, isolation of these genes is alarming that excessive use of antibiotics can lead to over expression of resistance genes and bacterial efflux pumps and the emergence of MDR phenotypes.

Background: Campylobacter jejuni and Campylobacter coli are identified as the major causes of acute gastroenteritis in humans. Because of the fastidious nature of Campylobacters, many clinical laboratories fail to routinely culture them. The detection of Campylobacter spp. using molecular-based techniques can be useful for diagnostic and epidemiological applications. This study aimed to develop a multiplex PCR assay for the simultaneous detection of C. jejuni and C. coli strains from clinical specimens. Materials and Methods: During a 19-month period, stool samples were collected from 980 children admitted to a hospital in Tehran, Iran and then examined. The samples were cultured on both Brucella agar and Modified Charcoal-Cefoperazone-Deoxycholate agar (mCCDA) media at 42° C for 48 h. To confirm suspected bacteria, Gram staining and other biochemical tests were carried out. Finally, after extracting DNA from pure cultures using the boiling method, the multiplex PCR assay was performed. Results: The multiplex PCR assay showed that Campylobacter spp. can be detected using 400 bp target product of cadF. It can also accurately distinguish between C. jejuni and C. coli species with different bands of 735 bp and 500 bp using hipO and asp genes, respectively. Conclusions: Results showed that the multiplex PCR assay can replace the biochemical assays for differentiating between C. jejuni and C. coli strains in a single-step PCR test.

Background: Gram-negative organisms producing Extended-spectrum beta-lactamases (ESBLs) are presented as a global problem. Klebsiella pneumoniae is considered as one of the most important microorganism of this group. The prevalence rate of K. pneumoniae species is increasing, and this increase is higher in the ESBL group, indicating the increase in antibiotic resistance. We must have sufficient knowledge about regional antibiotics resistance in order to monitor the prevalence rate and antimicrobial resistance among the isolates by appropriate treatment. In this regard, the objective of our study was to evaluate antimicrobial susceptibility among K. pneumoniae isolates by E-test method in Khatam ol Anbia hospital during 2015. Materials and methods: This descriptive cross-sectional study was carried out during 2015. All clinical samples were collected from intensive care unit (ICU) and general wards of Khatam ol Anbia hospital. All of the K. pneumoniae strains were detected by biochemical and microscopic tests. Antimicrobial susceptibility and minimum inhibitory concentration (MIC) were determined by disk diffusion and E-test methods. Descriptive statistics was used to analyze data. Results: About 62 K. pneumoniae strains were isolated from clinical samples of ICU and general wards during one year. Of these, 38 (61. 3%) isolates were isolated from intensive care unit, and 24 (38. 7%) isolates were isolated from the general wards. In this review, the least resistance was related to colistin (4. 8%) and Amikacin (14. 5%), respectively, and the most resistance was observed to the antibiotics of ciprofloxacin (66. 1%), ceftriaxone (62. 9%) and gentamicin (59. 7%), respectively. Resistance to imipenem was observed in 38. 7% of the isolates. Conclusion: The current study demonstrates that antibiotic resistance pattern is changing, and resistance to imipenem and colistin is rising, so this should be considered as a serious risk for admitted patients in hospital.

Background: Campylobacter species are the main food-borne pathogens which could cause gastroenteritis in humans. Contaminated chicken products have been documented as the primary sources of Campylobacter transmission to human. This study was done to test raw chicken meat products retailed in local markets in Tehran, Iran for the presence of Campylobacter coli and Campylobacter jejuni species. Materials and methods: A total of 70 raw chicken meat samples were collected during a three-month study. All the Campylobacter species were identified by biochemical and species-specific polymerase chain reaction (PCR). These isolates were investigated further to examine their potential virulence factors. Results: Campylobacter spp. were detected in 56% of the isolates and identified as C. coli. The results indicated that all of the isolates were positive for cadF, cdtA, iam genes. On the other hand, none of the isolates were positive for flaA and pladA virulence genes. Conclusion: Overall, the results showed that Campylobacter species were common contaminants in chicken meat, which should be screened for the presence of virulence determinants and for their involvement in food-borne diseases.

Background: Brucellosis is one of the most prevalent infectious diseases in Iran, which is shared between humans and animals. Brucellosis is caused by Brucella species and transmitted via unpasteurized milk or dairy products, which has been reported at least in 80 countries. The present study aimed to evaluate the prevalence rate of seropositive cases of brucellosis in Yazd, Iran. Materials and Methods: In this retrospective cross sectional study, seropositivity rate of brucellosis was examined for 12258 patients. The Wright test (1. 80 or higher) was used for diagnosing brucellosis. The obtained results were statistically evaluated by chi-square which is a trend analysis method. Results: The seropositivity rate of Wright test was reported to be 178 (1. 5%), which was significantly higher in the summer (43. 3%) and spring (29. 7%) than other seasons (P =. 000). It was also significantly higher in men (53. 9%) (P =. 000) than in women, and in people over 40 years (41%) (P =. 000) than in other age groups. Conclusion: Brucellosis seropositive studies provide very good information in order to help us in investigating the impact of brucellosis.

Background: Many comprehensive epidemiological studies have been done about fungal infections, which areone of the publichealth and therapeutic problemsin different communities. Since prevalence rate of fungal diseases and their etiologicalagents are changing over time, the aim of this study was to provideadditional informationabout visceral fungal infections(VFIs) in order to understand the ways of their dissemination, to preventdisease transmission, to eliminatecontamination sources and predisposingfactors, andto provide effective ways for their treatment. Materials and Methods: Sampleswere taken from the lesion of patients referred to medical mycology laboratory of Tehran University of Medical Sciencesfrom2014 to 2015. After providing direct wet mount of Potassium hydroxide (KOH) smears from these samples andsamples sent fromother medical centers, culturing onSabouraud Dextrose agar with chloramphenicol (SC) and brain heart infusion agar (BHI) mediawas performed. After growth, species were identified. Results: Froma total of 295 suspected samples, VFI wasproved in 69 cases (23%). Aspergillosis was the most prevalent infection among VFIs. Candidiasis, cryptococcosis andmucormycosis were in the late orders, respectively. Two patients were also infected byTrichosporon. The predominant species in aspergillosis infections wasAspergillusflavus, and the predominant species in candidiasis infections wasCandida albicans. Conclusion: According to the obtained results on the prevalence rate and incidence of VFIs between male and femalepatients in different age groups and also by taking into account the prevalent type of fungi and infectioussite of patients’ bodies, it is possible to take appropriate action for the prevention and treatment of these kinds of diseases by using the importantkeys of these results to research and study etiological and underlying factorsinvolved in these diseases.

Multidrug resistance in Acinetobacter baumannii is a growing public health concern all over the world. In the current study, the isolation and antimicrobial resistance pattern and detection of blaOXA-51 and lpxC genes by multiplex PCR method was performed. All the isolates demonstrated high levels of resistance rates to amikacin, ciprofloxacin, meropenem, imipenem, ceftriaxone, gentamicin, and colistin. Screening of two resistance genes by multiplex PCR showed that all the isolates contained blaOXA-51 and lpxC genes. As we previously reported, nosocomial infections caused by A. baumannii isolates are a major cause of morbidity and mortality in our hospital.

Background: The global control of the drug resistance tuberculosis has remained as major challenge. The present study was the first review study in the Middle East region in order to determine levels of Mycobacterium tuberculosis resistance to the first-line anti-TB drugs among both new and previously treated cases. Materials and Methods: The computer-assisted search was performed by using PubMed, Google Scholar, Scopus databases and related keywords. Within the time span of 1981-2014, a total of 480 articles were collected on the antibiotic resistance rates of M. tuberculosis in different countries of the Middle East region. About 63 relevant articles were selected by applying inclusion and exclusion criteria. Results: By using meta-analyses, we determined mono drug resistance, any drug resistance, and multidrug resistance (MDR-TB) rates in both new and previously treated TB patients living in different parts of the Middle East. Other aspects related to patients, antimicrobial resistance, and methods used to assess the resistance rate were also analyzed. Conclusion: The present study revealed that in comparison with the global average rate, the prevalence rate of drug resistant TB, especially MDR-TB, may be increasing in the Middle East. Therefore, in order to prevent the spread of drug-resistant isolates, detecting primary resistance to anti-TB drugs with the use of new rapid diagnostic methods is necessary.