High Prevalence of Class 1 to 3 Integrons Among Multidrug-Resistant Diarrheagenic Escherichia coli in Southwest of Iran

Abstract

ObjectivesHorizontal transfer of integrons is one of the important factors that can contribute to the occurrence of multidrug-resistant (MDR) bacteria. This study aimed to determine the prevalence of integrons among MDR Escherichia coli strains isolated from stool specimens and investigate the associations between the existence of integrons and MDR properties in the southwest of Iran.MethodsThere were 164 E. coli strains isolated from January 2012 to June 2012. Fecal specimens identified as E. coli by the conventional methods. Subsequently the antibiotic resistance was assessed using Clinical and Laboratory Standard Institute criteria. The presence of class 1–3 integrons and embedded gene cassettes was verified using specific primers by multiplex polymerase chain reaction assay.ResultsAmong a total of 164 studied samples, 69 (42.07%) isolates were multidrug resistant. Class 1 and class 2 integrons were present in 78.26% and 76.81% MDR isolates, respectively. For the first time in Iran, class 3 integron was observed in 26.09% MDR isolates. Significant correlations were identified between: class 1 integron and resistance to amikacin, gentamicin, chloramphenicol, ampicillin, tetracycline, nalidixic acid, and co-trimoxazole; class 2 integron and resistance to aminoglycosides, co-trimoxazole, cefalexin, ampicillin, and chloramphenicol; and class 3 integron and resistance to gentamicin, kanamycin, and streptomycin.ConclusionOur results indicate that integrons are common among MDR isolates and they can be used as a marker for the identification of MDR isolates. Therefore, due to the possibility of a widespread outbreak of MDR isolates, molecular surveillance and sequencing of the integrons in other parts of the country is recommended.

Colistin-Resistant Klebsiella pneumoniae: Prevalence of Integrons and Synergistic Out Turn for Colistin-Meropenem

“…In Press(In Press):e55099. 5 U n c o r r e c t e d P r o o f resistant K. pneumoniae is scary because the acquisition of resistance genes (horizontal gene transfer) is considered to play a major role in the dissemination of resistance properties (17). Prevalence of integrons in colistin-resistant isolates can lead to a serious threat; it may contribute to the spread of resistance as well as it will complicate the treatment of infections in the future (17).…”

“…5 U n c o r r e c t e d P r o o f resistant K. pneumoniae is scary because the acquisition of resistance genes (horizontal gene transfer) is considered to play a major role in the dissemination of resistance properties (17). Prevalence of integrons in colistin-resistant isolates can lead to a serious threat; it may contribute to the spread of resistance as well as it will complicate the treatment of infections in the future (17). Earlier, we reported the prevalence of colistin-resistant isolates (67% of K. pneumoniae) in Tamil Nadu (15), however, to the best of our knowledge, this is the first report on the prevalence of class 1 integrons in colistin-resistant K. pneumoniae in the Southern part of India.…”

“…To confirm whether K. pneumoniae isolates borne integrons, the existence of class 1, 2, and 3 integrase genes in all the isolates were screened by multiplex polymerase chain reaction (PCR) using the primers intI1, intI2, and intI3 (17). The presence of class 1 integrons were detected by amplifying 5' CS and 3' CS along with intI1 were as class 2 integron by the amplification of intI2 using attI2-F and orfX-R for gene cassette characterization.…”

Multidrug-Resistant <b><i>Escherichia coli</i></b> Strains Isolated from Patients Are Associated with Class 1 and 2 Integrons

“…that are resistant to cephalosporins, aminoglycosides, fluoroquinolones or trimethoprim-sulfamethoxazole [4,5]. MDR is a major health care problem because it has increased mortality and morbidity worldwide [6,7]. The easy spread of resistant genes has been a fundamental force in the rapid evolution of resistance to a wide range of unrelated antibiotics among diverse bacteria.…”

Integron in Gram negative bacteria: Classes and fitness cost

“…28 In another study performed on 164 E. coli isolates, class 1 and class 2 integrons and class 3 were found in 78.26%, 76.81% and 26.09% MDR isolates, respectively. 29 A surveillance study investigated the occurrence of class 3 integron among 587 Gram negative isolates reported the prevalence of class 3 integron to be 0.7%. 30 …”