فهرست مطالب gopal nandlal agrawal

Antimicrobial resistance in bacterial pathogens is associated with high morbidity and mortality. We aimed to evaluate antibiotic resistance and β-lactamase production in clinical isolates of a tertiary care hospital in Central India.
Clinical isolates (n=6472 isolates) from patients with infection were identified using standard microbiological techniques. Antibiotic susceptibility testing was performed according to the CLSI guidelines using the Kirby-Bauer disc diffusion technique. AmpC production in Enterobacteriaceae isolates was tested in screening test. Cloxacillin combined disc diffusion test was performed for both inducible and non-inducible AmpC using cefoxitin disc with and without cloxacillin. Metallo-β-lactamase production in Enterobacteriaceae isolates was tested in screening test (positive= zone diameter of Majority of the bacteremia cases were caused by Staphylococcus aureus (43.13%), non-fermenting spp. (27.44%) and coagulase-negative staphylococci (11.76%). Escherichia coli (55.85%) was the main cause of urinary tract infection followed by Acinetobacter spp. (11.71%) and Klebsiella pneumoniae (10.36%). No resistance to linezolid was seen in Gram-positive isolates. Frequency of vancomycin-resistance was about 9% in Enterococcus spp. Methicillin resistance was seen in 19% of S. aureus isolates. Enterobacteriaceae and Citrobacter freundii isolates were completely resistant to aminopenicillin, first and second-generation cephalosporins and cefamycin. Moreover, Klebsiella isolates were resistant to aminopenicillin. Enterobacteriaceae isolates showed resistance to aminopenicillin (89.87%), cephalosporins (54-90%) and cephamycin (37-45%). E. coli isolates were sensitive to PIT (87-96%) and imipenem (99.68-100%). ESBL production was seen in 166 Enterobacteriaceae isolates (30.24%) in DDST and CPCT. AmpC production was seen in 15 (2.73%) Enterobacteriaceae isolates. Total β-lactamase production was found in 19.23% of the isolates tested. The frequency of β-lactamase production was highest in K. pneumoniae (51.67%). Co-production of β-lactamases was not observed.
It is necessary to closely monitor drug resistance and β-lactamase production. Moreover, it is recommended to perform routine β-lactamase testing in microbiology laboratories for determining prevalence of antibiotic resistance and controlling their spread.

Recently, Acinetobacter has emerged as significant hospital pathogen, notoriously known to acquire antibiotic resistance to most of the commonly prescribed antimicrobials. Many risk factors are associated with Acinetobacter infections, especially in patients in intensive care unit (ICU). This study aims to isolate Acinetobacter from various clinical specimens and to determine its antimicrobial sensitivity pattern.

Identification, speciation and antimicrobial sensitivity testing were performed using the standard microbiological techniques. Slime production was also tested by microtiter plate and tube method.

From the processed clinical specimens, 107 Acinetobacter strains (1.02%) were isolated of which 76 (0.74%) isolates were from general wards and 31 (11.96%) were from ICU. Significantly higher percentage of Acinetobacter strains was found in ICU compared with general wards (P < 0.05). Most common Acinetobacter infection was abscess. Infections were more common in males and were associated with major risk factors such as post-surgical, diabetes mellitus, catheterization, extended hospital stay and prolonged antibiotic usage. Acinetobacter baumanii was the most common species isolated to cause abscess, wound infection, etc. 62.61% and 28.97% isolates produced slime by microtiter plate and tube method. Imipenem was most sensitive drug followed by amikacin. Ceftazidime, cefotaxime, piperacillin were most resistant. 43.00% isolates were IPM resistant. A. baumanii was more resistant to commonly used antimicrobials.

Acinetobacter nosocomial infections resistant to most antimicrobials have emerged, especially in ICU. Early identification and continued surveillance of prevalent organism will help prevent the spread of Acinetobacter in hospital environment.