ABSTRACT
Background: Wound infections continue to be a causeof concern as they can delay healing and cause woundbreakdown. Their effective treatment demands quickisolation and identification of causative organisms withappropriate antibiotic sensitivity pattern. Material andMethods: Wound swab and pus samples received frominpatient as well as outpatient department of all agegroups and both genders were processed usingconventional media as well as chromogenic medium(HiCrome UTI) and results of both were compared.Antibiotic sensitivity testing was done on Vitek 2Compact automated system. Results: Among 342samples, 77% showed growth. Fifty eight percentagewere Gram negative and 42% were Gram positiveorganisms. Polymicrobial growth was seen in 11% ofsamples. HiCrome UTI isolated all organisms inculture. Colony characteristics and colour of all isolateson HiCrome UTI were comparable to theiridentification on Vitek 2 Compact. Among the Grampositive organisms, commonest was MethicillinSensitive Staphylococcus aureus (MSSA 42%)followed by Methicillin Resistant Staphylococcusaureus (MRSA 33%), Enterococcus faecalis (10%),Staphylococcus epidermidis (8%), Staphylococcushaemolyticus (3%), Streptococcus pyogenes (2%) andStreptococcus agalactiae (2%). Most of the Grampositive organisms were sensitive to vancomycin,teicoplanin, linezolid and clindamycin The commonGram negative organisms were E. coli (36%),Klebsiella pneumoniae (20%), Pseudomonasaeruginosa (18%), Proteus mirabilis (7%),Enterobacter cloacae (6%) and Acinetobacterbaumannii (4%). Most of the Gram negative organismswere sensitive to cefepime, beta lactams-betalactamase inhibitors, aminoglycosides and fluoroquinolones. Conclusion: Gram-negative organismspredominated in our study. HiCrome UTI agar can beused as a cost-effective approach for rapid isolation ofall organisms. It gives definite identification ofcommon organisms and thus reduces turn-around-timefor the same. It provides presumptive identification ofinfrequent organisms which can be further confirmedby simple biochemical tests. Hence these properties ofHiCrome UTI agar help serve the purpose especiallyfrom mixed cultures and in resource constraint settings
ABSTRACT
Background: Infections by Gram positive isolates are increasing due to which their antibiotic sensitivity pattern is changing. This has revived interest in Macrolide-Lincosamide Streptogramin Group B (MLSB) antibiotics. Misuse of MLSB antibiotics hasincreased resistance in Gram-positive organisms especially Staphylococcus species to these drugs. Clindamycin is an important drug for treatment of Gram-positive isolates. Hence detection of inducible clindamycin resistance in these clinical isolates is required to prevent therapeutic failure and avoid inadvertent use of this drug. Aim and Objectives: To detect inducible clindamycin resistance among Gram positive isolates obtained from clinical samples. Material and Methods: The study was carried out over a period of one year (Jan-Dec 2018). A total of 461 Gram positive isolates of Staphylococcus species, Streptococcus pneumoniae and Beta-haemolytic Streptococcus were identified from various clinical samples and antibiotic susceptibility done on Vitek2 Compact usi g GP ID, and 628 and ST01 cards respectively. According to CLSI 2017, D-zone test was performed for detection of inducible clindamycin resistance for strains resistant to erythromycin. Results: Staphylococcus aureus (SA) isolates were 59%, Staphylococcus epidermidis (SE) 21%, other Coagulase Negative Staphylococcus (CONS) 16%, Streptococcus pyogenes (Group A-beta haemolytic) 2%, Streptococcus agalactiae (Group B betahaemolytic) 1% and Streptococcus pneumoniae (alpha haemolytic) 1%. Isolates of Methicillin Sensitive Staphylococcus aureus (MSSA) were 58% and Methicillin Resistant Staphylococcus aureus (MRSA) were 42%. Frequencies of MS (clindamycin sensitive) phenotypes, inducible clindamycin resistance (MLSBi) phenotypes and phenotypes showing constitutive resistance (MLSBc) were 44%, 12% and 3% respectively among MSSA and 34%, 39% and 8% respectively among MRSA. Among SE, MS, MLSBc and MLSBi phenotypes were 39%, 24% and 12% respectively and 8%, 44% and 30% respectively among other CONS. One isolate of S. pyogenes was of MLSBi phenotype and none among S. agalactiae and S. pneumoniae. Conclusion: The study emphasizes the significance of conducting D-zone test along with routine antimicrobial susceptibility testing to guide in therapy and avoid treatment failures.