Search

Objectives The incidence of infections due to Mycobacterium avium complex (MAC) and Mycobacterium abscessus (MABS) is increasing worldwide. Current antimycobacterial agents are not sufficiently effective against nontuberculous mycobacteria (NTM) and there is a need for new drugs. This study aimed to estimate the overall in vitro activity of clofazimine (CFZ) against MAC and MABS clinical isolates. Methods We systematically searched four databases up to 1 March 2020 to identify relevant studies. Studies were included if they used the Clinical and Laboratory Standards Institute (CLSI) criteria for drug susceptibility testing (DST). We assessed the pooled in vitro CFZ resistance rate in MAC and MABS clinical isolates using a random- effects model. Sources of heterogeneity were evaluated using Cochran's Q and the I2 statistic. Potential for publication bias was explored using Begg's and Egger's tests. All analyses were conducted using Stata 14.0. Results A total of 20 publications (11 reports for MAC and 15 for MABS) were included. The pooled rates of in vitro resistance to CFZ in clinical isolates of MAC and MABS were 9.0% [95% confidence interval (CI) 3.0–17.0%] and 16.0% (95% CI 4.0–34.0%), respectively. There was no evidence of publication bias. Conclusion This study reports the frequency of CFZ resistance in clinical isolates of MAC and MABS. According to the results, establishing accurate DST methods for detecting CFZ resistance, performing DST for all NTM isolates to provide effective treatment, and continuous monitoring of drug resistance are suggested for the prevention and control of CFZ-resistant NTM.

Nowadays, novel antimicrobial strategies are being developed which focus on debilitating, rather than killing the microorganisms. In this regard, anti-biofilm therapy is one of the important ways to combat bacterial infections. Therefore, the aim of the current study was to evaluate the anti-biofilm activity of Carvacrol against E. faecalis by means of its effects on biofilm formation as well as on the gene expression levels of the two biofilm related genes, Epa and Esp.A total of 40 clinical strains of E. faecalis were collected from three hospitals in Tehran, Iran during 2020. These isolates were confirmed by biochemical and genotypic methods. Antibacterial and anti-biofilm activity of Carvacrol essence were determined according the standard protocol. Finally, expression level of the biofilm related genes (Epa and Esp) were evaluated before and after the treatment with Carvacrol.A total of 14 isolates were considered as strong biofilm producers and were used for analysis. Carvacrol essence showed the best antibacterial activity at 2,500 μg/mL concentration against all the isolates, the biofilm formation capacity was decreased by Carvacrol essence, and it was statistically significant (p0.05). Expression levels of the Esp gene were decreased in 5 isolates while increased in 3 isolates following the Carvacrol treatment. Ex-pression levels of the EpaI gene was significantly decreased (p0.05) in 4 isolates following the Carvacrol treatment.In conclusion, the results presented in this study suggest that carvacrol extract exhibits significant antimicrobial and anti-biofilm properties against E. faecalis, even against vancomycin resistant isolates.

Background: Non-tuberculous mycobacteria (NTM), specifically Mycobacterium avium complex (MAC), is an increasingly prevalent cause of pulmonary dysfunction. Clofazimine has been shown to be effective for the treatment of M. avium complex, but there were no published large-scale analyses comparing clofazimine to non-clofazimine regimens in MAC treatment. The objective of this large-scale meta-analysis was to evaluate patient characteristics and treatment outcomes of individuals diagnosed with MAC and treated with a clofazimine-based regimen.Methods: We used Pubmed/Medline, Embase, Web of Science, and the Cochrane Library to search for studies published from January 1, 1990 to February 9, 2020. Two reviewers (SSH and NY) extracted the data from all eligible studies and differences were resolved by consensus. Statistical analyses were performed with STATA (version 14, IC; Stata Corporation, College Station, TX, USA).Results: The pooled success treatment rate with 95% confidence intervals (CI) was assessed using random effect model. The estimated pooled treatment success rates were 56.8% in clofazimine and 67.9% in non-clofazimine groups. Notably, success rates were higher (58.7%) in treatment of HIV patients with disseminated infection.Conclusions: Treatment was more successful in the non-clofazimine group overall. However, HIV patients with disseminated infection had higher treatment response rates than non-HIV patients within the clofazimine group.

Gram-negative bacteria cause an alarming level of resistance to carbapenems by producing carbapenemases which can become a global epidemic. According to a report about Pseudomonas aeruginosa released by the World Health Organization in 2017, carbapenem resistance is classified as highest priority. The main objectives of the present study are to evaluate the frequency of carbapenem resistance, detect Metallo-β-Lactamases and β-lactamases, identify the molecular characterization of blaNDM-1 in Pseudomonas aeruginosa isolates, and report blaNDM-1 for the first time among children in Iran. This study selected 70 clinical isolates from different cities of Iran during 2019–2020. Disk diffusion method and Minimum Inhibitory Concentration were employed to run antimicrobial susceptibility testing. In order to detect carbapenemases and Metallo-β-Lactamases, mCIM and CDDT were used, respectively. In addition, PCR technique and DNA sequencing were utilized to identify and confirm the genes related to β-lactamases and Metallo-β lactamases (blaNDM, blaVIM, blaIMP, blaSIM, blaGIM, blaSPM, and blaKPC). The highest resistance rates were observed for Meropenem 67.1 (47) and Imipenem 65.7 (46) while the lowest resistance rate was observed for Piperacillin/Tazobactam 35.7 (25). Of all isolates, 55.7 (39) and 54.3 (38) constituted carbapenemase-producing and MBL isolates, respectively. PCR results exhibited blaNDM-1 21.4, followed by blaIMP 7.1 and blaVIM 2.9 of genes. Moreover, 1.4 of these isolates co-produced blaNDM-1 and blaVIM genes. These isolates did not comprise blaSIM, blaSPM, blaGIM, and blaKPC genes. Three isolates of positive blaNDM-1 isolates were notably detected among children. The results showed that Metallo-β-Lactamases, especially blaNDM-1, were highly prevalent among adults and children of Iran. © 2021 Elsevier Inc.

Cell cultures are developed from tissue samples and then disaggregated by mechanical, chemical, and enzymatic methods to extract cells suitable for isolation of viruses. With the recent advances in technology, cell culture is considered a gold standard for virus isolation. This paper reviews the evolution of cell culture methods and demonstrates why cell culture is a preferred method for identification of viruses. In addition, the advantages and disadvantages of both traditional and modern cell culture methods for diagnosis of each type of virus are discussed. Detection of viruses by the novel cell culture methods is considered more accurate and sensitive. However, there is a need to include some more accurate methods such as molecular methods in cell culture for precise identification of viruses.

Cell cultures are developed from tissue samples and then disaggregated by mechanical, chemical, and enzymatic methods to extract cells suitable for isolation of viruses. With the recent advances in technology, cell culture is considered a gold standard for virus isolation. This paper reviews the evolution of cell culture methods and demonstrates why cell culture is a preferred method for identification of viruses. In addition, the advantages and disadvantages of both traditional and modern cell culture methods for diagnosis of each type of virus are discussed. Detection of viruses by the novel cell culture methods is considered more accurate and sensitive. However, there is a need to include some more accurate methods such as molecular methods in cell culture for precise identification of viruses.

The main mechanism of quinolone resistance in Klebsiella (K) pneumoniae is caused by mutation ofporin-related proteins and efflux pumps. This study aimed to investigate the prevalence of ciprofloxacin-resistant K pneumoniae in burns patients and to understand the role of the AcrAB multidrug efflux system on minimal inhibitory concentration (MIC) of ciprofloxacin. For this reason, 52 K pneumoniae samples were collected from burns patients and evaluated for the mechanism of ciprofloxacin resistance. The results demonstrated that 40 isolates of K pneumoniae were ciprofloxacin-resistant and 35 showed the mutation on gyrA locus. By inhibition of the efflux system, the MIC yield showed a significant decrease. Therefore, it could be concluded that the high rate of mutation on the gyrA locus in combination with quinolone resistance was responsible for ciprofloxacin resistance and by inhibition of AcrA, the resistance rate showed a significant decrease in K pneumoniae isolated from burns patients.

Aims of this study were to investigate on antibiotic resistance and molecular epidemiology of K.pneumoniae producing ESBLs isolates of respiratory tract infections in some major hospitals in Iran. K.pneumonaie were obtained of patients with RTI. K. pneumoniae producing ESBLs detected by screening, confirming and PCR methods. During the 12-month period, a total of one hundred and thirteen of K.pneumoniae were found from RTI in three cities in different region of Iran which Sixty seven strains (59.2%) were ESBLs producer. In Ilam hospitals, seventeen strains (43.6%), in Milad hospital, thirty-seven strains (74%) and in Emam Reza hospital, thirteen strains (54.2%) were ESBLs producer. The findings showed that among sixty-seven K.pneumoniae producing ESBLs, Sixty-three strains (94%) were positive for blaSHV, eleven strains (16.4%) contained blaTEM and sixteen strains (23.9%) harbored blaCTX-M. Imipenem was found as an effectiveness antibiotic. In the current study, Majority of the ESBLs production had occurred in Milad hospital in Tehran (74%). In conclusion, spreading ESBL-producing strains is a concern, as it causes limitations to the antimicrobial agents for optimal treatment of patients.

Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen of increasing risk on community. This study aims at determining the risk of MRSA transfer from coins as silent and underestimated reservoir in community. One hundred swabs from coins were collected from college students in Malaysia. A series of identification and differentiating tests were conducted for precise identification of MRSA bacteria. Moreover, this study compared the efficacy of the different identification tests with gold standard, polymerase chain reaction (PCR) assay. The tests used were tube coagulase, DNase agar test, antibiogram, several routine biochemical identification tests and PCR assays. PCR assay used specific primers for resistance or ID -related genes: mecA, ermA, ermB, ermC, msrA, linA, femA, and nuc genes. A total of 37 bacterial isolates were isolated from college students’ coins; non-PCR assays of identification and resistance detection revealed the presence and spread of MRSA in coins of 2 college students. PCR-amplification of the nuc gene was used as a baseline test to detect S. aureus. PCR showed only one isolate as true MRSA. False positive MRSA by disc diffusion assay might be attributed to low pH and high thymidine content of Muller Hinton agar medium. Collectively, coins proved to be possible source for the transfer of MRSA in community of college students in South East Asia. Moreover, PCR assay for identification of S. aureus resistance proved to be superior on other methods. Key words : Staphylococcus aureus , MRSA, nail, PCR, resistance.

Background: Staphylococcus aureus is known to be responsible for nosocomial infections, and the typing method was useful in managing the reservoir of bacteria. The main aim of this study was to determine the prevalence of S. aureus in the nares and hands of nurses working in Imam Khomeini hospital, Ilam, Iran, as well as to determine the clonal relatedness, antimicrobial susceptibility profiles, different virulence, and resistance determinants among these isolates. The evolution of mupirocin activity in the eradication of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) colonization in the nares of the healthcare workers in Ilam, Iran, was also determined in this study.Materials and Methods: In this cross-sectional study, 80 nurses, auxiliary nurses, and service workers from Imam Khomeini Hospital were enrolled. MRSA, antibiotic susceptibility, and virulence determinants were evaluated. Then, the isolates were subjected to pulsed field gel electrophoresis (PFGE) and Staphylococcal cassette chromosome mec typing. Results: Our results demonstrated that 23% of isolates were MRSA. PFGE results demonstrated that pulsotypes A (3 out of 30; 10%) and J (3 out of 30; 10%), pulsotypes E (2 out of 30; 6.7%), M (2 out of 30; 6.7%), P(2 out of 30; 6.7%), and V (2 out of 30; 6.7%) were the most predominant pulsotypes, respectively. Conclusion: We cannot give conclusive suggestions about the correlation between nasal carriage and infections, but we suggest the monitoring of all healthcare workers annually, decontamination of their noses by using mupirocin and other antistaphylococcal agents, and also the washing of their hands at least every 2 h.

Background Methicillin-resistant Staphylococcus aureus (MRSA) is one the most important pathogens across the world, associated with increased mortality rate compared to other Staphylococcal species. Objectives The present study aimed to investigate different virulence determinants among MRSA isolates from Ilam, Iran. Materials and Methods Overall, 100 MRSA isolates were collected from selected hospitals of Ilam, Iran. Oxacillin screening test and molecular detection of mecA were carried out by polymerase chain reaction (PCR) to confirm the methicillin resistance. Presence of the virulence genes et A, B, tst, sea a, b, c, d and e were assessed using multiplex PCR. Results All the tested isolates were susceptible to vancomycin, but resistant to penicillin (100%), erythromycin (31%), clindamycin (27%), ciprofloxacin (27%), gentamicin (21%), and amikacin (16%). The frequencies of antibiotic resistance and virulence genes were as follows: tst 46%, eta 1%, etb 3%, sea 41%, seb 2%, sec 14%, and see 31%. Conclusions Results of the present study showed that the tst and sea genes had high frequencies among the MRSA isolates. The increased prevalence of MRSA isolates containing different virulence genes, probably accompanied by antimicrobial resistance, can complicate the therapy of MRSA isolates.

Objectives of this study were to study the molecular epidemiology of ESBL-producing Klebsiella pneumoniae in selective hospitals in Iran, to determine the prevalence of TEM, SHV and CTX-M genes responsible for ESBL production among ESBL-producing K. pneumoniae, to investigate the susceptibility of Klebsiellae spp producing ESBLs towards non-beta-lactam antibiotics, all in different seasons. Clinical isolates of K. pneumoniae were identified during Mar. 2007 to Apr. 2008 in Ilam hospitals, the province in west of Iran. All isolates were found in surgery wards. ESBL activity was first evaluated using the standard disc diffusion test for cephalosporins and monobactam, then using the double-disc synergy test between cephalosporins and clavulanate. PCR assay had done for ESBLs genes detection. The results showed sixteen K.pneumoniae were identified by chemical methods. No resistance had occurred among K.pneumoniae toward non-beta-lactam antibiotics. BlaSHV was dominant gene responsible for ESBLs production while just one blaTEM along with blaSHV were found. BlaCTX-M was not responsible for ESBLs production in our study. 37.5% K.pneumoniae producing ESBLs in surgery ward in west of Iran must be considerable and need to further study in different part of hospital in Ilam and in Iran. Strict antibiotic policy should be adopted in hospitals to estimate the impact of higher resistance in bacteria and to take steps for reducing these resistances.

decades later in patients who were treated with ESWL compared to controls. This study was undertaken to determine if patients treated with ESWL at our institution demonstrated an increased prevalence of hypertension and/or diabetes compared to patients treated with ureteroscopy(URS) or percutanteous nephrostolithotomy(PNL) after twenty years of follow up. METHODS: 948 patients who underwent treatment for renal or ureteral stones between 1986 and 1989 were contacted by mail and asked to complete a detailed health questionnaire. Patients over 80 years of age at the time of the initial procedure were excluded from analysis. Treatments included ESWL using the HM3 lithotripter, ureteroscopy, or percutaneous nephrostolithotomy. Frequencies of disease states were tabulated. The t test was used to compare the prevalence of hypertension and diabetes across treatment groups. RESULTS: 90 patients responded to the survey with a mean follow up time of 20 years. 4 patients declined to participate. 14 were deceased. Of these 14 patients, in 4 cases family members completed the survey on the deceased patient’s behalf. 19% of patients were female. 65 patients were treated with ESWL and 12 were treated with either PNL or URS. Prevalence of hypertension and diabetes is