COLISTIN RESISTANCE IN CARBAPENEM-RESISTANT KLEBSIELLA PNEUMONIAE STRAINS

Objective: There is an increasing use of colistin consequent to increase in the infections caused by carbapenem-resistant Klebsiella pneumoniae.The present study was conducted to determine the minimum inhibitory concentration (MIC) of colistin and the resistance pattern of colistin in carbapenem-resistant K. pneumoniae (CRKP) strains in our intensive care unit (ICU).Methods: Antibiotic susceptibility testing for other antimicrobial agents was done by Kirby-Bauer disk diffusion method. MIC of colistin was determined by agar dilution method. The results of antibiotic susceptibility testing were interpreted as per Clinical Laboratory Standard Institute guidelines 2016 and MIC of colistin were interpreted as per European Committee on Antimicrobial susceptibility testing. The carbapenem resistance was phenotypically detected by modified hodge test and imipenem/imipenem ethylenediaminetetraacetic acid disk method.Results: Out of 518 K. pneumoniae, 329 were resistant to carbapenems, and 91 isolates showed resistance to colistin. The MIC of colistin ranged between 4 and >512 ug/ml and MIC90 was 16 ug/L and MIC50 was 4 ug/ml. A majority of the colistin-resistant isolates were found in multidisciplinary ICU (85/91).Conclusion: The emergence of colistin-resistant strains is a major problem due to limited treatment options for infections caused by CRKP carbapenemase producing K. pneumoniae. Colistin should not be used alone, combination therapy should be preferred

Two Case Reports of Ochrobactrum anthropi Bacteremia: An Overlooked Pathogen

Ochrobactrum anthropi, due to its robust survival abilities, has been known to cause nosocomial and opportunistic infections, posing both diagnostic and therapeutic challenges. Low virulence, indolent clinical presentation, and lack of awareness on their clinical significance attribute to the underreporting of the same. We report two cases of bacteremia in oncology patients presented to us in a short span of 6 months, which indicates that such infections might be quite common in immunocompromised hosts. Both our strains were susceptible to carbapenems, trimethoprim/sulfamethoxazole, and minocycline, and recovered with monotherapy. More vigilant and accurate diagnostic techniques need to be followed not to miss such pathogens. Early identification and administration of appropriate antibiotics have been associated with a good outcome

MUPIROCIN RESISTANCE IN STAPHYLOCOCCUS AUREUS IN A TERTIARY CARE HOSPITAL OF SOUTH INDIA – A PROSPECTIVE STUDY

Objective: Mupirocin is a topical antibiotic used for the treatment of skin and soft tissue infections caused by Staphylococcus aureus and for the nasal decolonization of methicillin-resistant S. aureus (MRSA). The increasing reports of resistance to mupirocin are a matter of concern. We undertook this study to detect and differentiate the mupirocin resistance pattern and to analyze the susceptibility pattern among S. aureus isolates of our hospital.Methods: This is a prospective laboratory-based study conducted during the period May–September 2014. Clinical samples that grew S. aureus during the study period were tested for mupirocin resistance using the 5 μg and 200 μg discs. Minimum inhibitory concentration (MIC) detection of resistant strains was performed using the E-test.Results: Mupirocin resistance was seen in 4.81% of our S. aureus isolates; all of which exhibited high-level resistance with MIC ≥1024 μg/ml.Conclusions: The resistance is bound to rise with the increased usage of mupirocin; regular testing will help in tackling this upcoming problem and in preserving this important antibiotic against MRSA