Molecular characterization of class 1 integrons in MDR<i>Pseudomonas aeruginosa</i>isolated from clinical settings in Iran, Tehran

Shahcheraghi, Fereshteh; Badmasti, Farzad; Feizabadi, Mohammad M.

doi:10.1111/j.1574-695x.2009.00636.x

Cited by 31 publications

(29 citation statements)

References 21 publications

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“…In particularly, the cassette aadA6-orfD was found in 89 % of the isolates. This array seems to be widespread in other countries (Garza-Ramos et al, 2010;Shahcheraghi et al, 2010;Borgianni et al, 2011). Unlike aadA6-orfD and aacC3-cmlA5, the cassette aacA4-catB8-aadA1 detected in one of the isolates is usually reported in Acinetobacter baumannii (Turton et al, 2005), although this gene has been observed previously in P. aeruginosa (Jeong et al, 2009).…”

Section: -H Chew 416mentioning

confidence: 83%

New integron gene arrays from multiresistant clinical isolates of members of the Enterobacteriaceae and Pseudomonas aeruginosa from hospitals in Malaysia

Kor

Choo

Chew

2013

Journal of Medical Microbiology

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This study investigated 147 multidrug-resistant Enterobacteriaceae and Pseudomonas aeruginosa isolates from hospitalized patients in Malaysia. Class 1 integrons were the most dominant class identified (45.6 %). Three isolates were shown to contain class 2 integrons (2.0 %), whilst one isolate harboured both class 1 and 2 integrons. No class 3 integrons were detected in this study. In addition, the sul1 gene was amplified in 35 % of isolates and was significantly associated with the presence of integrase genes in an integron structure. RFLP and DNA sequencing analyses revealed the presence of 19 different cassette arrays among the detected integrons. The most common gene cassettes were those encoding resistance towards aminoglycosides (aad) and trimethoprim (dfr). As far as is known, this study is the first to identify integron-carrying cassette arrays such as aadA2-linF, aacC3-cmlA5 and aacA4-catB8-aadA1 in the Malaysian population. Patients' age was demonstrated as a significant risk factor for the acquisition of integrons (P50.028). Epidemiological typing using PFGE also demonstrated a clonal relationship among isolates carrying identical gene cassettes in Klebsiella pneumoniae and P. aeruginosa but not in Escherichia coli isolates.

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Section: -H Chew 416mentioning

confidence: 83%

New integron gene arrays from multiresistant clinical isolates of members of the Enterobacteriaceae and Pseudomonas aeruginosa from hospitals in Malaysia

Kor

Choo

Chew

2013

Journal of Medical Microbiology

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“…Our present study showed high expression of resistance genes to aminoglycosides among Salmonella isolates. These results match those from other reports that revealed that cassettes for aminoglycosides are common in class I integrons (Huang et al ., ; Kang et al ., ; Shahcheraghi et al ., ). The most prevalent arrays in our S. Enteritidis were aadA6 ‐ orfD .…”

Section: Discussionmentioning

confidence: 97%

Characterization of class I integrons among Salmonella enterica serovar Enteritidis isolated from humans and poultry

Firoozeh

Zahraei-Salehi

Shahcheraghi

et al. 2011

FEMS Immunol Med Microbiol

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A total of 84 Salmonella enterica serovar Enteritidis (S. Enteritidis) isolates, 42 of human and 42 of poultry origin, were characterized for antimicrobial resistance patterns and class I integrons. Among them, 58 (69%) S. Enteritidis were multidrug-resistant (MDR) and showed resistance to two or more antibiotic classes. By PCR assays and DNA sequencing, 50 (59.5%) S. Enteritidis isolates were found to carry class I integrons. Amplification of internal variable regions of class I integrons revealed five different arrays (0.75 kb only, 1 kb only, 1.3 kb only, both 1 and 1.2 kb, and both 1 and 1.3 kb). The integrons were further sequenced and the dfrA25 (0.75 kb), aadA1 (1 kb), aadA2 (1 kb), bla(PSE1) (1.2 kb) aadA6-orfD (1.3 kb) gene cassette arrays were identified. Ciprofloxacin minimum inhibitory concentration (MIC) values for the three isolates that showed resistance or reduced susceptibility via the disc diffusion method were 0.5-4 μg mL(-1), although only three isolates exhibited resistance to cefteriaxone (MIC: 128-256 μg mL(-1)) and four isolates were resistant to florfenicol (MIC: 32-128 μg mL(-1)). In conclusion, the high rates of multidrug-resistance and class I integrons found among S. Enteritidis isolates in humans and poultry in Tehran suggest that efforts are needed to confine the prevalence of MDR Salmonella isolates.

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“…However, a previous study from one medical centre in Taiwan indicated that the prevalence of MDR-PA infections increased significantly from 1.74% in 2001 to 6.31% in 2004 [20]. The reported prevalence of MDR-PA varies amongst Asian countries, from 1.62% in Japan to 4.49% in India and 5.46% in Iran [21][22][23]. The rate is similar (4.7%) in Europe but is much higher (10%) in the USA [24,25].…”

Section: Discussionmentioning

confidence: 99%

Interplay between mutational and horizontally acquired resistance mechanisms and its association with carbapenem resistance amongst extensively drug-resistant Pseudomonas aeruginosa (XDR-PA)

Shu

Chia

Siu

et al. 2012

International Journal of Antimicrobial Agents

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Between 2003 and 2009, the prevalence of extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) increased significantly in northern Taiwan from 1.0% to 2.1%. Molecular methods were used to investigate the genetic relatedness and carbapenem resistance mechanisms of a collection of 203 non-repetitive XDR-PA isolates available for study. Using pulsed-field gel electrophoresis (PFGE), 52 genotypes were observed; one predominant genotype (pulsotype 1) was found in 57.6% of the isolates. Polymerase chain reaction (PCR), sequencing and quantitative reverse-transcriptase PCR analyses demonstrated that one horizontally acquired mechanism [metallo-β-lactamase (MBL) genes] and two mutational mechanisms (efflux and porins) accounted for the carbapenem resistance. The most predominant horizontally acquired mechanism was carriage of bla(VIM-3), which was found in 61.1% of isolates. Decreased expression of oprD was the most prevalent mutational mechanism and was found in 70.0% of the XDR-PA isolates, whereas overexpression of mexA was found in 27.6% of the isolates. The highlight of this study was the discovery of statistically significant relationships between certain horizontally acquired and mutational resistance mechanisms and their contribution to carbapenem susceptibility. MBL-producers expressed significantly lower MexAB and higher OprD than non-MBL-producers. Amongst isolates without an acquired β-lactamase gene, oprD expression was significantly reduced, whilst expression of efflux pumps was increased. Reduced OprD expression alone or the production of VIM-type MBLs showed similar contributions to a low to intermediate MIC(50) (minimum inhibitory concentration for 50% of the organisms) for carbapenems. Isolates with reduced OprD expression that simultaneously harboured bla(VIM) exhibited high levels of resistance to carbapenems, which implied that these two mechanisms had a synergistic effect on the MICs.

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Molecular characterization of class 1 integrons in MDRPseudomonas aeruginosaisolated from clinical settings in Iran, Tehran

Cited by 31 publications

References 21 publications

New integron gene arrays from multiresistant clinical isolates of members of the Enterobacteriaceae and Pseudomonas aeruginosa from hospitals in Malaysia

New integron gene arrays from multiresistant clinical isolates of members of the Enterobacteriaceae and Pseudomonas aeruginosa from hospitals in Malaysia

Characterization of class I integrons among Salmonella enterica serovar Enteritidis isolated from humans and poultry

Interplay between mutational and horizontally acquired resistance mechanisms and its association with carbapenem resistance amongst extensively drug-resistant Pseudomonas aeruginosa (XDR-PA)

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