Antibiotic resistance patterns and extended-spectrum β-lactamase production among Acinetobacter spp. isolated from an intensive care Unit of a hospital in Kerman, Iran

Abstract

BackgroundThe global increase in multidrug resistance of Acinetobacter spp. has created widespread problems in the treatment of patients in intensive care units (ICUs) of hospitals. To assess the sensitivity of Acinetobacter isolates to antibiotics routinely used in ICUs, we investigated antibiotic resistance patterns and extended-spectrum β-lactamase (ESBL) production among Acinetobacter spp. isolated from the ICU of a university hospital in Kerman, Iran.MethodsFifteen isolates of Acinetobacter spp. were recovered from one hundred clinical specimens collected from the ICU of Afzalipoor Hospital in Kerman, Iran, from October 2010 to June 2011. Preliminary antibiotic sensitivity testing was carried out using the disk-diffusion breakpoint assay, and MICs of different antibiotics were determined using the E-test. ESBL production was detected by a double-disk synergy test and confirmed by a phenotypic confirmatory test. Substrate hydrolysis in the presence and absence of the following inhibitors was carried out using the rapid fixed-time method: para-chloromercuribenzoate (p-CMB), clavulanic acid, sulbactam, and NaCl.ResultsOverall, 73.3% of the isolates were resistant to imipenem (MIC range 240-128 µg/mL) and 66% to ciprofloxacin (MIC range 240-64 ± 0.08 µg/mL). All of the isolates were fully resistant (MIC 240 µg/mL) to piperacillin, while 93.3%, 53.3%, and 93.3% were resistant to piperacillin + tazobactam (MIC 240 µg/mL), amikacin (MIC range 128-16 µg/mL), and cefepime (MIC range 240-60 µg/mL), respectively. The isolates were also resistant to chloramphenicol and tetracycline: MICs of these two agents were ≥ 240 µg/mL. The test for ESBL production was positive for only three isolates (nos. 1, 10, and 15). The rate of substrate hydrolysis was highest in the presence of p-CMB (80.2 ± 0.02) and lowest in the presence of NaCl (2.1 ± 0.01) (P ≤ 0.05).ConclusionsMany isolates of Acinetobacter spp. are resistant to almost all antibiotics routinely used in the ICU of our hospital, including imipenem, ciprofloxacin, and piperacillin + tazobactam. Three isolates were ESBL producers. The other isolates exhibited high resistance to β-lactams, but they did not produce any ESBL enzymes.

Distribution of Aminoglycoside Resistance Genes Among Acinetobacter Baumannii Strains Isolated From Burn Patients in Tehran, Iran

“…In our study, the resistance to tobramycin and gentamicin was 63% and 86%, respectively. Shakibaei et al in a study conducted on 50 clinical strains of A. baumannii in Kerman, Iran, reported that 73.3% of strains were resistant to imipenem, 66% to ciprofloxacin, and 53.3% to amikacin (26). In another study performed by Aliakbarzafeh et al in Tabriz, it was found that 94% of A. baumannii isolates were resistant to kanamycin, 86% to gentamycin, 81% to amikacin, and 63% to tobramycin (14).…”

Limited genetic diversity and extensive antimicrobial resistance in clinical isolates of Acinetobacter baumannii in north-east Iran

“…Besides the oxacillinases in A. baumannii, ESBLs could result in high resistance to cephalosporin antibiotics (Shakibaie et al, 2012). Unfortunately, the TEM variant of ESBL was not studied in Iran (Asadollahi et al, 2012); however, comprehensive multi-country studies have revealed high rates of TEM distribution in A. baumannii isolates (Chaudhary, 2012).…”

“…In addition, neighbouring countries of Iran are affected by a lengthy history of political adversity, weak central government, civil wars, terrorism, poverty and weak health systems, and the presence of nearly four million foreign nationals from these countries has placed additional pressure on the structure of Iranian health care, especially in Mashhad. As a result, the transmission of infectious diseases from these countries has changed the epidemiological features of these diseases in Iran (Soleimanpour et al, 2014). Thus, it is important to investigate the epidemiology of infectious disease in this city.…”

Iron limitation enhances acyl homoserine lactone (AHL) production and biofilm formation in clinical isolates ofAcinetobacter baumannii

“…[7][8][9] There are several reports indicating emergence of the multidrug resistant A. baumannii (MDR-AB) in different hospital units in Iran. 10 The rate of Infections due to MDR-AB in Tehran (Iran) hospitals showed a drastic increase (30%) in resistance to different antibiotics within 5 years, while all the isolates remained susceptible to either minocycline or tobramycine. 11 A recent investigation of MDR-AB infection associated with respiratory tract specimens from one teaching hospital in the southern Tehran showed that among 101 isolates, 96% were resistant to third generation of cephalosporins, 93% to amikacin, and 85% to ciprofloxacin.…”