Infections in Iran

Currently some parasitic and viral infections, tuberculosis, brucellosis and hospital-acquired infections are challenging issues in Iran. Despite decreasing the rate of some infectious diseases in Iran in recent years, improved sanitation, active surveillance, comprehensive infection control strategies and monitoring appropriate use of antibiotics are indispensable. © 2018 The Autho

A frequency and molecular typing study of methicillin-resistant staphylococcus aureus isolates in teaching hospitals in Shahrekord, southwestern Iran

Methicillin-resistant Staphylococcus aureus (MRSA) remains a significant public health problem and treatment challenge. Objectives: This study was conducted to determine the frequency, molecular types, and drug resistance of S. aureus isolated from nasal carriers in two teaching hospitals (Hajar and Kashani) in Shahrekord, southwestern Iran. Methods: In this cross-sectional study, 262 nasal specimens were obtained from healthcare staff. The disk-diffusion method was used to detect MRSA. Nine antibiotic disks were used to determine the antibiotic susceptibility pattern. Staphylococcal cassette chromosome mec (SCCmec) types were identified by the multiplex polymerase chain reaction (PCR). The data analysis was performed using Fisher’s exact test with SPSS software. Results: Forty-eight (18.8%) specimens were identified as S. aureus, of which 30 (11.45%) specimens were methicillin resistant. The nasal colonization rate of the MRSA isolates was not associated with age or gender (P > 0.05). The highest resistance (33%) recorded was to rifampin, and all the isolates were susceptible to quinupristin-dalfopristin, vancomycin, and linezolid. The SCCmec results showed that 16.7%, 6.7%, 20%, and 56.6% of MRSA isolates were types I, II, III, and IV, respectively. Conclusions: Nasal isolates of MRSA were prevalent among hospital staff. The highest level of resistance was to rifampin, and all the isolates were susceptible to quinupristin-dalfopristin, vancomycin, and linezolid. SCCmec type 4 was the most frequent MRSA isolate. © 2016, Ahvaz Jundishapur University of Medical Sciences

Molecular epidemiology and nitrofurantoin resistance determinants of nitrofurantoin-non-susceptible Escherichia coli isolated from urinary tract infections

Objectives: The worldwide emergence of multidrug-resistant uropathogens has resulted in the revival of old antibiotics such as nitrofurantoin (NIT) for the treatment of uncomplicated urinary tract infections (UTIs). This study aimed to identify determinants of NIT resistance and to investigate the genetic diversity of NIT-resistant (NIT-R) Escherichia coli isolates. Methods: Six NIT-R and three NIT-susceptible clinical E. coli isolates from patients with UTI were studied. The susceptibility of the isolates to various classes of antibiotics was evaluated by disk diffusion. The presence of plasmid-encoded efflux pump genes (oqxA and oqxB) was investigated by PCR. Nucleotide sequences of the nfsA, nfsB and ribE genes were determined. The genetic relatedness of the NIT-R isolates was evaluated by multilocus sequence typing (MLST). Results: All six NIT-R isolates were characterised with high-level NIT resistance (MIC � 512 mg/L) and they belonged to five distinct STs including ST131 (n = 2), ST73, ST405, ST10 and ST354 (n = 1 each). Amikacin, carbapenems, minocycline, tigecycline and fosfomycin were the most active agents against the studied uropathogens. The oqxA and oqxB genes were not detected in any isolate. All NIT-R isolates harboured inactivating genetic alterations in nfsA and nfsB NfsA H11Y, S33N, S38Y, W212R substitutions, �g638 (frameshift), �a64-g73 (frameshift) and NfsB F84S, P45S, W94Stop, E197Stop substitutions, �nfsB locus. The ribE gene of most isolates was unaffected, except for one isolate co-harbouring a deleterious RibE G85C substitution and NfsA/B alterations. Conclusion: NIT resistance in the studied E. coli isolates was mainly mediated by nfsA and nfsB alterations. © 201

Microbiological qualification of air, water and dialysate in a haemodialysis centre; a new focus on Legionella spp.

Background and Objectives: The microbiological monitoring of the water used for haemodialysis is important especially for Legionella and non-fermentative bacteria since patients with end stage renal disease (ESRD) are suffering from deteriorated function of immune system. Materials and Methods: A total 50 water and dialysate samples were weekly collected over a period of 10 weeks from 5 sites. Total and faecal coliforms were determined by utilizing the most probable number (MPN) method. For isolation of Legionella, water samples were inoculated on a BCYE medium. DNA extraction was performed and was used to amplify 16S rRNA gene of Legionella species. Airborne bacteria were sampled using a single stage Andersen air sampler. Results: Out of total 50 water samples, 24 samples had bacterial contamination. The highest rate of Legionella contamination was observed in the storage tank (67 cfu/ml). Legionella was not isolated from the dialysate effluent samples. The highest rate of total bacterial count was related to the dialysate effluent and the maximum total count of coliforms was related to the reverse osmosis. The isolated bacteria were Gram-negative bacilli (mostly Pseudomonas isolates), Gram-positive cocci (mostly Micrococcus spp.) and Gram-positive bacilli (mostly Bacillus spp.). Six samples were contaminated with coliforms. No faecal coliform was isolated from the samples. Conclusion: These results indicated that dialysis machine is an important source of contaminations such as Staphylococcus, Pseudomonas and Legionella. Therefore an efficient prevention program is needed to eliminate bacterial contamination of dialysis water system. Moreover, in haemodialysis centres, periodic surveillance programs for microbiological qualification can lead to a better planning for disinfection of haemodialysis water systems. © 2016, Tehran University of Medical Science. All rights reserved

Rapid Detection of Rifampicin- and Isoniazid-Resistant Mycobacterium tuberculosis using TaqMan Allelic Discrimination

Objectives: Multidrug-resistant tuberculosis (MDR-TB) is a global problem that many countries are challenged with. Rapid and accurate detection of MDR-TB is critical for appropriate treatment and controlling of TB. The aim of the present study was to evaluate the TaqMan allelic discrimination without minor groove binder (MGB) as a rapid, efficient, and low-cost method for detection of drug resistant strains of Mycobacterium tuberculosis. Methods: A total of 112 M. tuberculosis isolates from cases with diagnosed TB were subjected to drug susceptibility testing (DST), using the proportion method. Resistant isolates were tested for characterization of mutations in the rpoB and KatG genes by TaqMan genotyping. Results: Of 112 M. tuberculosis isolates for which DST was performed, three, one, and two isolates were MDR, rifampin (RIF) resistant, and isoniazid (INH) resistant, respectively. According to the threshold cycle (Ct) and curve pattern of mutants, TaqMan probes detect all of the mutations in the analyzed genes (katG 315, AGC�ACC, rpoB 531, TCG�TTG, and rpoB 531, TCG�TGG). Conclusion: The present study suggests that drug-resistant strains of M. tuberculosis can be detected by pattern's curve or Ct with TaqMan probes without MGB in real-time polymerase chain reaction (PCR). © 2016

Mupirocin resistance in Staphylococcus aureus: A systematic review and meta-analysis

Objectives: Staphylococcus aureus is one of the most common pathogens causing nosocomial and community-acquired infections associated with high morbidity and mortality. Mupirocin has been increasingly used for treatment of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) infections. The aim of this study was to determine the prevalence of mupirocin-resistant S. aureus (MuRSA), mupirocin-resistant MRSA (MuRMRSA), high-level MuRSA (HLMuRSA) and high-level MuRMRSA (HLMuRMRSA) worldwide. Methods: Online databases including Medline, Embase and Web of Science were searched (2000�2018) to identify studies addressing the prevalence of MuRSA, MuRMRSA, HLMuRSA and HLMuRMRSA. STATA v. software was used to interpret the data. Results: Of the 2243 records identified from the databases, 30 and 63 studies fulfilled the eligibility criteria for MuRSA and MuRMRSA, respectively. Finally, 27 and 60 studies were included separately for HLMuRSA and HLMuRMRSA, respectively. The analyses revealed pooled and averaged prevalences of MuRSA, MuRMRSA, HLMuRSA and HLMuRMRSA of 7.6 95% confidence interval (CI) 6.2�9.0%, 13.8% (95% CI 12.0�15.6%), 8.5% (95% CI 6.3�10.7%) and 8.1% (95% CI 6.8�9.4%), respectively. Conclusion: Overall, these results show a global increase in the prevalence of HLMuRSA and HLMuRMRSA among clinical S. aureus isolates over time. However, there was only a significant increase in the prevalence of MuRMRSA compared with the other categories, especially MuRSA. Since mupirocin remains the most effective antibiotic for MSSA and MRSA decolonisation both in patients and healthcare personnel, a reduction of its effectiveness presents a risk for invasive infection. Monitoring of mupirocin resistance development remains critical. © 2019 International Society for Antimicrobial Chemotherap

Global prevalence and distribution of vancomycin resistant, vancomycin intermediate and heterogeneously vancomycin intermediate Staphylococcus aureus clinical isolates: a systematic review and meta-analysis

Vancomycin-resistant Staphylococcus aureus (VRSA), Vancomycin-intermediate S. aureus (VISA) and heterogeneous VISA (hVISA) are subject to vancomycin treatment failure. The aim of the present study was to determine their precise prevalence and investigate prevalence variability depending on different years and locations. Several international databases including Medline (PubMed), Embase and Web of Sciences were searched (data from 1997 to 2019) to identify studies that addressed the prevalence of VRSA, VISA and hVISA among human clinical isolates around the world. Subgroup analyses and meta-regression were conducted to indicate potential source of variation. Publication bias was assessed using Egger�s test. Statistical analyses were conducted using STATA software (version 14.0). Data analysis showed that VRSA, VISA and hVISA isolates were reported in 23, 50 and 82 studies, with an overall prevalence of 1.5 among 5855 S. aureus isolates, 1.7 among 22,277 strains and 4.6 among 47,721 strains, respectively. The overall prevalence of VRSA, VISA, and hVISA before 2010 was 1.2, 1.2, and 4, respectively, while their prevalence after this year has reached 2.4, 4.3, and 5.3. The results of this study showed that the frequency of VRSA, VISA and hVISA after 2010 represent a 2.0, 3.6 and 1.3-fold increase over prior years. In a subgroup analysis of different strain origins, the highest frequency of VRSA (3.6) and hVISA (5.2) was encountered in the USA while VISA (2.1) was more prevalent in Asia. Meta-regression analysis showed significant increasing of VISA prevalence in recent years (p value � 0.05). Based on the results of case reports (which were not included in the calculations mentioned above), the numbers of VRSA, VISA and hVISA isolates were 12, 24 and 14, respectively, among different continents. Since the prevalence of VRSA, VISA and hVISA has been increasing in recent years (especially in the Asian and American continents), rigorous monitoring of vancomycin treatment, it�s the therapeutic response and the definition of appropriate control guidelines depending on geographical regions is highly recommended and essential to prevent the further spread of vancomycin-resistant S. aureus. © 2020, The Author(s)

Methicillin-resistant staphylococcus epidermidis in Iran: A systematic review and meta-analysis

Objective: Methicillin-resistant Staphylococcus epidermidis (MRSE) remains one of the most prevalent drug-resistant bacteria causing health care infections. Limited data are available about how the frequency of MRSE changed in Iran over the past years. The current study aimed at determining the frequency of MRSE in different cities of Iran. Methods: Databases including Web of Sciences, Scopus, Embase, Medline, and Iranian databases were searched to find studies addressing the frequency of MRSE in Iran published from Mar 2006 to Jan 2016. The data were analyzed using comprehensive meta-analysis version 2.2 (Biostat). Of the 139 records identified in the databases, 15 studies met the inclusion criteria. Results: The analyses showed that the frequency of MRSE infections was 73.9 95% confidence interval (95% CI) 61.4-83.4 among culture-positive cases of S. epidermidis in different parts of Iran. The frequency of MRSE was higher in the studies conducted from 2011 to 2015, based on further stratified analyses. Conclusions: The regular surveillance on antimicrobial susceptibility pattern and formulation of definite antibiotic policy may control high rate of MRSE associated infections in Iran. Moreover, rapid and reliable diagnosis of MRSE isolates and regular screening of the personnel and surfaces of hospitals in terms of MRSE are indispensable. © 2018, Archives of Clinical Infectious Diseases