Assessment of extended-spectrum β-lactamases and integrons among Enterobacteriaceae in device-associated infections: multicenter study in north of Iran

Abstract

BackgroundDevice-associated nosocomial infections (DA-NIs), due to MDR Enterobacteriaceae, are a major threat to patient safety in ICUs. We investigated on Extended-spectrum β-lactamases (ESBL) producing Enterobacteriaceae and incidence of integrons in these bacteria isolated from ventilator-associated pneumonia (VAP) and catheter-associated urinary tract infections (CAUTIs) in 18 governmental hospitals in the north of Iran.MethodsIn this cross-section study, the antibiotic susceptibility test was performed using the MIC method; also, phenotypically detection of ESBL-producing bacteria was carried out by the double-disk synergy (DDS) test. Presence of ESBL-related genes and integron Classes 1 and 2 was evaluated by the PCR method.ResultsOut of a total of 205 patients with DA-NIs, Enterobacteriaceae were responsible for (72.68%) of infections. The most common DA-NIs caused by Enterobacteriaceae were VAP (77.18%), CAUTI (19.46%), and sepsis due to VAP (3.35%). The most frequently Enterobacteriaceae were; Klebsiella pneumoniae 75 (24; 32% ESBL positive), E. coli 69 (6; 8.69% ESBL positive) and Enterobacter spp. 5 (5; 100% ESBL positive). Distribution of ESBL-related genes was as follows: bla-SHV (94.3%), bla-CTX (48.6%), bla-VEB (22.9%) and bla-GES (17.14%). The incidence rate of integron class 1 and class 2 was (82.92%) and (2.9%) respectively. Eight types of ESBL-producing bacteria were observed.ConclusionsDue to the fact that the emergence rate of ESBL Enterobacteriaceae is increasing in DA-NIs, co-incidence of different types of ESBL genes with integrons in 75–100% of strains in our study is alarming for clinicians and healthcare safety managers. Therefore, regional and local molecular level estimations of ESBLs that are agents of DA-NIs are critical for better management of empiric therapy, especially for patients in ICUs.Electronic supplementary materialThe online version of this article (doi:10.1186/s13756-016-0143-2) contains supplementary material, which is available to authorized users.

Multidrug and co-resistance patterns of non-fermenting Gram-negative bacilli involved in ventilator-associated pneumonia carrying class 1 integron in the North of Iran

“…6 Therefore in this study, the high rates of class 1 integron among P. aeruginosa and A. baumannii were to be expected due to the high rates of resistance among these isolates. In addition, association of antibiotic resistance and presence of class 1 integron in most antibiotic-resistant isolates was significant (p<0.05) - Table 4.…”

“…The patient must have had at least one of the following criteria: new onset of purulent sputum or change in character of sputum; organism cultured from blood or from a specimen obtained by tracheal aspirate, bronchoalveolar lavage or bronchial brushing, or biopsy". 6 All NFGNB that were confirmed as causing VAP were evaluated. Deep tracheal aspirates from endotracheal tubes were obtained by head nurses and samples were immediately transported in transport sterile container tubes to the microbiology laboratory.…”

“…As of now, five classes of integrons have been described, among which class 1 is most frequently identified in clinical isolates, and the strains carrying these genes are resistant to multiple classes of antimicrobial agents. 6 Hitherto, many studies have reported high rates of VAP due to MDR NFGNB. On the other hand, being aware of local epidemiology of the agents is of great importance.…”

Extended-Spectrum Beta-Lactamases Producing Pseudomonas aeruginosa Isolated From Patients With Ventilator Associated Nosocomial Infection

“…Furthermore, ESBL-producing bacteria cause serious infections and have high mortality rates. ESBL-bacteria are capable of efficiently hydrolyzing many beta-lactam antibiotics, including cephalosporins and monobactams (9,10).…”

Emergence of Extensively Drug Resistant Acinetobacter baumannii-Encoding Integrons and Extended-Spectrum Beta-Lactamase Genes Isolated from Ventilator-Associated Pneumonia Patients

“…The inclusion criteria were as follows: 1) onset of purulent sputum or changes in the sputum; and 2) cultured organisms from blood samples or specimens obtained via tracheal aspirate analysis, bronchoalveolar lavage, or biopsy (13). Sampling was carried out over 1 year.…”