فهرست مطالب

  • Volume:8 Issue: 1, 2019
  • تاریخ انتشار: 1398/01/28
  • تعداد عناوین: 8
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  • Absera Fikre , Tsegaye Tewelde , Tamrat Shaweno * Pages 1-12
    Background
    Multi-drug resistance tuberculosis (MDR) have been a hazardous concern both in developed and developing countries. Little information is available regarding the determinants of MDR-TB in Ethiopia, and hence, We assessed the probable determinants of MDR-TB in Southern Ethiopia.
    Methods
    A case-control study was conducted. Cases were TB patients with simultaneous resistance to at least rifampicin (RMP) and isoniazid (INH) and controls were TB patients who were susceptible to first line TB drugs and registered as cure or treatment completed from March 2016 to March 2018. We used simple random sampling method to select cases and controls. Data were collected using semi-structured questionnaire with face to face interview and patients’ clinical record review. Bivariate and multivariate logistic regression analysis was done to determine determinants of MDR-TB. Significance level was adjusted at p-value <0.05.
    Results
    A total 102 cases together with 102 controls participated in the study. The mean age for cases and controls were 35.6 years (SD± 13.6) and 31.2 years (SD ±15.4) respectively. Factors that independently predicted MDR-TB were: time to reach health facility taking more than three hours (AOR 2, 95%CI=0.10-0.45), history of contact with known MDR-TB patients (AOR 6, 95%CI=1.8-19.7), patients with no formal education (AOR 4.40, 95%CI=1.7-13.3), patients who didn’t get counseling (AOR 5, 95% CI=1.8-14) and patients who didn’t hear about MDR-TB (AOR 6.8, 95% CI=2.99-15.3).
    Conclusion
    Multiple factors predicted MDR-TB. Patients: at distant location, with known contact history of MDR-TB patients, with low level of literacy, who lack information on MDR-TB and who didn’t get counseling deserve special attention.
    Keywords: Determinants, MDR-TB, Southern Ethiopia
  • Yalda Ostadi, Ali Akbar Rezai, Mahdi Moghadampour, Jamshid Faghri * Pages 13-20
    Background
    Due to the extensive usage of antibiotics in recent decades, the emergence of multiple drug-resistant (MDR) strains has dramatically increased. In the present study, we studied the distribution and involvement of drug efflux system in conferring resistance to amikacin in MDR isolates of Acinetobacter baumannii isolated from hospitalized patients.
    Methods
    In this cross-sectional study 80 MDR A. baumannii were isolates isolated from hospitalized patients in Alzahra hospital, Isfahan, Iran. A. baumannii isolates were identified by standard microbiologic procedure and were confirmed by specific PCR primers. Minimum inhibitory concentration (MIC) was determined by agar dilution method according to CLSI guidelines. Carbonyl cyanide 3-chlorophenylhydrazon (CCCP) was used as an efflux pump inhibitor for amikacin susceptibility. The presence of efflux genes was detected by PCR method.
    Results
    Antibiotic susceptibility results showed that 39 of isolates had MIC ≥32 μg/mL and were amikacin-resistant. Totally, 41 isolates which had an amikacin MIC ≥2 μg/mL were tested for reduction of MIC in presence of 25 μg/mL efflux pumps inhibitor. After the treatment, 25 (61%) isolates had ≥2 fold and 15 (36.6%) isolates had 4 fold reduction in amikacin MIC. The results of PCR-amplifications indicated that the presence rate of AdeA, AdeB, AdeC, AbeM and AdeS genes were 100%, 96.3%, 95%, 98.8%, and 95%, respectively.
    Conclusion
    In summary, significant involvement of drug efflux system in conferring resistance to amikacin along with high distribution of efflux genes suggests an alternative therapy using antibiotics in combination with efflux inhibitors in the fight against MDR isolates of A. baumannii.
    Keywords: Acinetobacter baumannii, AdeABC genes, Amikacin, Efflux pumps, MDR
  • Alireza Dadashi , Nima Hosseinzadeh , Ebadallah Shiri Malekabad *, Hossein Ghaderi Pages 21-26
    Background
    Despite major advances in the management of ventilator-associated pneumonia, its pathogenesis is not clearly known. Recently, the role of gastric colonization has been proposed. We compared the prevalence of H. pylori by serology in patients with VAP and in control subjects to determine the role of H. pylori and gastric colonization in the pathogenesis of VAP.
    Methods
    118 intubated and mechanically ventilated patients were included and divided into two groups; 59 subjects with VAP and 59 control patients. Results of the serologic tests, demographic characteristics and time of blood sampling were registered.
    Results
    Mean age in seropositive patients was significantly higher. 71.2% in the VAP group and 61.01% in controls were IgG seropositive (P=0.24). IgM seropositivity was 23.73% versus 8.47% in VAPs and controls, respectively (P=0.024). By increasing the time of intubation, more patients became seropositive for IgM (Pearson’s correlation coefficient=0.4, P=0.002).
    Conclusion
    IgM seropositivity and serum level were significantly higher in VAP patients. Also by increasing the duration of intubation and time of sampling, serum levels and seropositivity for IgM increased significantly.
    Keywords: Gastric colonization, Helicobacter pylori, Pathogenesis, Serology, Ventilator-associated pneumonia
  • Nasrin Noohi *, Maliheh Talebi Pages 27-36
    Background
    This study was done to determine the level of high level gentamicin resistant (HLGR) and vancomycin resistant enterococci (VRE) in the healthy normal human population living in Tehran, Iran.
    Methods
    A total of 700 fecal samples were isolated from the period of September 2007 to September 2008 and the species were identified by the biochemical tests and PCR. Antibiotic susceptibility test, gentamicin and vancomycin resistant genes and the conjugation tests were performed to evaluate the transferability of the drug resistant genes. The clonality of the isolates was also determined by PFGE.
    Results
    The results showed that the prevalence of HLGR and VRE in the healthy normal population were 16.6% (100) and 1% (6) for HLGR and VRE, respectively. Amongst the HLGR enterococci, the most frequent species were found to be Enterococcus faecalis in 63% of the isolates. This was followed by E. faecium (33%), E. gallinarum (3%) and E. casseliflavus (1%). The frequency of the gentamicin resistant genes were 99 (99%), 91 (91%), 3(3%) and 1(1%) for aac(6')-Ie-aph(2'')-Ia, aph(3')-IIIa, ant(4')Ia and aph(2'')-Id genes, respectively. Among the vancomycin resistant genes, vanA was found in 1% (6) of isolates only. PFGE revealed high heterogeneity among the 63 E. faecalis strains and 33 E. faecium with 31 and 28 different patterns, respectively. The 6 VR E. faecium revealed 6 different patterns.
    Conclusion
    The prevalence and heterogenous populations of HLGR in the normal flora of the humans found here were higher than reports from many countries, may be suggestive of excessive antibiotic usage in Iranian.
    Keywords: Antibiotic resistance, Enterococcus, PFGE, Normal flora, Vancomycin resistance genes
  • Saeide Saeidi , Mahboubeh Mohsenbeygi , Javad Roustakhiz , Fereshteh Javadian , Mehdi Hassanshahian * Pages 37-44
    Background
    The aim of this study was to investigate the antimicrobial and anti-biofilm effects of Mentha piperita and Zataria multiflora on some pathogenic bacteria.
    Methods
    Mentha piperita and Zataria multiflora essential oils were obtained by using the clevenger device. The bacterial cultures were prepared as standard samples. Finally, antimicrobial and anti-biofilm activity was determined by microdilution method.
    Results
    The results of this study showed that the lowest inhibitory concentration of essential oil of Zataria multiflora was 1.25 mg / ml, while the rest of the bacteria were inhibited at a concentration of 2.5 mg / ml. The lowest and highest inhibitory concentrations were found as 1.25 and 5 mg / ml against Pseudomonas aeruginosa.
    Conclusion
    The results of the study showed that Z. multiflora essential oil showed antimicrobial and anti-biofilm activity that could be used to treat infections caused by these bacteria.
    Keywords: Antibacterial activity, Anti biofilm activity, Essential oil, Pathogen
  • Akram Amini , Amirmorteza Ebrahimzadeh Namvar * Pages 45-50
    Background
    Pseudomonas aeruginosa has recently emerged as one of the main causes of nosocomial infections in the intensive care unit due to vast antibiotic resistance potency. The aim of this study was to investigate the antimicrobial resistance pattern and evaluation of the frequency of beta-lactamase genes in Pseudomonas aeruginosa strains.
    Methods
    Generally, 42 P. aeruginosa strains were collected from different clinical specimens. The phenotypic and genotypic tests such as disc diffusion, Modified Hodge test and molecular detection of blaIMP, blaIMP1, blaVIM2, and blaKPC genes were performed.
    Results
    According to the results, by disk diffusion method 33 (78.58%) to Cefotaxime, 31 (73.8%) of strains were resistant to Ceftriaxone, and 31 (73.8%) to Co-trimoxazole, while the lowest resistance was observed in case of Polymyxin B 3 (7.15%). On the other hand 4 (9.52%) of strains were recognized as MHT positive. Moreover, 26 (61.9%) of isolates were detected as multi drug resistance strains. In addition, 2 (4.7%) of isolates harbored blaIMP, 2 (4.7%) blaIMP1 and 10 (23.8%) blaVIM2 genes, whereas the blaKPC gene was not reported.
    Conclusion
    According to the results, the prevalence of beta-lactamase genes and antibiotic resistance pattern in patients with high levels of hospitalization is essential. Therefore, it is necessary to identify the strains containing β-lactamase genes for better control and treatment.
    Keywords: Multi Drug Resistance, Nosocomial Infections, Pseudomonas aeruginosa
  • Fataneh Moein Jahromi , Mohammad Kargar *, Abbas Doosti , Somayeh Handali Pages 51-57
    Background
    Streptococcus pneumoniae is an important cause of respiratory tract infections. Due to the recent incidence of antibiotic resistance to commonly used antibiotics, the use of quinolones in the treatment of S. pneumoniae has been taken into consideration. The aim of this study was to evaluate the molecular mechanisms of quinolone resistance in isolated strains.
    Methods
    This study was carried out on 45 strains of S. pneumoniae isolates from clinical samples. Initially, using biochemical tests, S. pneumoniae strains were determined and using lytA gene specific primers, these strains were accomplished. Antibiotic resistance was assessed by Clinical & Laboratory Standards Institute (CLSI) criteria and eventually, and then adopting Polymerase Chain Reaction-Restriction Fragment Length polymorphism (PCR-RFLP) techniques were studied with Sau3A and MspI enzymes. Also, point mutations associated with antibiotic resistance was evaluated in parC and parE genes.
    Results
    In 45 strains isolated, resistance to nalidixic acid, ciprofloxacin, ofloxacin, norfloxacin and levofloxacin was; 82.22%, 73.43%, 53.33%, 48.88%, and 42.22%, respectively. In clinical samples, 34 (75.55%) strains with mutations in the parC genes and 14 (31.11%) strains with mutations in parE gene were detected. Using statistical analysis, it was found that there was a significant relationship between mutations in the parC genes and resistance to nalidixic acid, ciprofloxacin, norfloxacin and levofloxacin. However, mutations in parE genes only showed the significant correlation with resistance to norfloxacin exclusively. On the contrary, unlike other studies, we demonstrated that a mutation in the parE gene could be involved in low-level resistance to quinolones.
    Conclusion
    Due to the considerable resistance to quinolones, evaluation of these mutations is necessary in other parts of the country.
    Keywords: parC, parE, Quinolones resistance, Streptococcus pneumoniae, Topoisomerase IV