ABSTRACT
Coagulase-negative staphylococci [CNS] are a main cause of nosocomial infection. The main purpose of this study was to determination of frequency of CNS isolates in in hospitalized patients and their susceptibility pattern to antimicrobial agents. During 11 month study, 65 CNS clinical isolates were recovered from hospitalized patients in different wards of hospital. In vitro susceptibility of isolates to 12 antimicrobial agents Penicillin; Ampicilin; Cephalothin; Cefoxitin; linezolid; Nitofurantoin; Erythromycin; Norfloxacin; Gentamicin; Vancomycin; Chloramphenicol and Oxacillin was performed by Kirby-Bauer's Disk diffusion method according to Clinical and Laboratory Standards Institute [CLSI] criteria. Out of 1875 samples of hospitalized patients 65[3.47%] patients were infected with CNS. Twenty one [32.3 %] were isolated from the urine samples, 17[26.1%] from sputum, 15[23.1%] from pus samples, 8[12.3 %] from ear swabs, 3[4.7%] from fluid and 1[1.5%] from blood sample. All of CNS isolates were sensitive to nitrofurantoin. The rates of resistance to the majority of antibiotics tested varied between 4.5% and 100 %. The rate of resistance to beta lactam antibiotics, Chloramphenicol, erythromycin, gentamycin was high [more than 70%]. The most of isolates remained susceptible to linezolid, and nitofurantoin. All of isolates were susceptible to vancomycin. Multi-drug resistant CNS with reduced susceptibility to linezolid and nitrofurantoin are emerging pathogens of clinical concern. Monitoring of antibiotic resistance with attention to multi-resistant profile and aware to practitioners in the field is necessary
ABSTRACT
The emergence and increase in the incidence of Extended-spectrum beta lactamase [ESBL] producing Escherichia coli [E. coli] has become an emerging challenge especially in hospitalized patients with urinary tract infection [UTI]. The aim of the present study was to survey the frequency of bla CTX-M genotype in ESBL producing E. coli isolated from hospitalized patients with urinary tract infection and determination of their antibiotic resistance pattern. A total of 135 E. coli isolates were collected and isolated from patients with UTI. The isolates were subjected to confirmatory phenotype tests for the presence of ESBL. 75 E. coli isolates were confirmed as ESBL-positive by double disc synergy test. In vitro susceptibility of ESBL isolates to 15 antimicrobial agents amoxicillin, penicillin, ceftazidime, cefotaxime, cefoxitin, ceftriaxone, cefixime, cephalexin, co-trimoxazole, gentamicin, nalidixic acid, ciprofloxacin, nitrofurantoin, amikacin, and imipenem was performed by Kirby-Bauer's Disk diffusion method according to Clinical and Laboratory Standards Institute [CLSI, 2012] guideline. PCR method was used to identify bla CTX-M gene in 75 ESBL positive strains. PCR and sequence analysis showed that 75 [55.5%] isolates produced bla CTX-M genes. In vitro susceptibility of ESBL producing E. coli showed that all of them were resistant to amoxicillin and penicillin. The rates of resistance to the majority of tested antibiotics varied among 61% to 100%, with the exception of amikacin [14.7%] and imipenem [2.7%]. Our results showed that the frequency of bla CTX-M was strikingly high [93.3%] in patients with UTI. These data confirmed that the frequency of bla CTX-M genes was high among E. coli isolated from patients with UTI. The trend of multidrug-resistant profile has been associated with bla CTX-M gene is alarming. Therefore, it is very important to establish a routine screening of ESBL in clinical isolates to prevent dissemination of resistant isolates in health care settings