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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.

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.

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.

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.