Antifungal susceptibility of invasive Candida bloodstream isolates from the Asia-Pacific region.

Bloodstream infections caused by Candida species are of increasing importance and associated with significant mortality. We performed a multi-centre prospective observational study to identify the species and antifungal susceptibilities of invasive bloodstream isolates of Candida species in the Asia-Pacific region. The study was carried out over a two year period, involving 13 centers from Brunei, Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam. Identification of Candida species was performed at each study center, and reconfirmed at a central laboratory. Susceptibility testing was performed using a commercial broth dilution panel (Sensititre YeastOne YST-010, Thermofisher, United Kingdom) with susceptibility categorisation (S = susceptible, S-DD = susceptible dose-dependent) applied using breakpoints from the Clinical Laboratory Standards Institute. Eight hundred and sixty-one Candida isolates were included in the study. The most common species were C. albicans (35.9%), C. tropicalis (30.7%), C. parapsilosis (15.7%), and C. glabrata (13.6%). Non-albicans species exceeded C. albicans species in centers from all countries except Taiwan. Fluconazole susceptibility was almost universal for C. albicans (S = 99.7%) but lower for C. tropicalis (S = 75.8%, S-DD = 6.1%), C. glabrata (S-DD = 94.9%), and C. parapsilosis (S = 94.8%). Echinocandins demonstrated high rates of in vitro susceptibility (S>99%) against C. albicans, C. tropicalis, and C. parapsilosis This study demonstrates that non-albicans species are the most common isolates from bloodstream infections in most countries in the Asia-Pacific region, with C. tropicalis as the predominant species. Because of the prevalence of reduced susceptibility to fluconazole in non-albicans species, the study indicates that echinocandins should be the antifungal of choice in clinically unstable or high-risk patients with documented candidemia.

Inducible Clindamycin Resistance in Staphylococcus aureus Isolated from Clinical Samples.

INTRODUCTION: The resistance to antimicrobial agents among Staphylococci is an increasing problem. This has led to renewed interest in the usage of Macrolide-Lincosamide-Streptogramin B (MLS(B)) antibiotics to treat Staphylococcus aureus (S. aureus) infections. The resistance to macrolide can be mediated by msr A gene coding for efflux mechanism or via erm gene encoding for enzymes that confer inducible or constitutive resistance to MLS(B)antibiotics. In vitro routine tests for clindamycin susceptibility may fail to detect inducible clindamycin resistance due to erm genes resulting in treatment failure, thus necessitating the need to detect such resistance by a simple D test on a routine basis. MATERIALS AND METHODS: One hundred and ninety S. aureus isolates were subjected to routine antibiotic susceptibility testing including oxacillin (1 µg) and cefoxitin (30 µg) by modified Kirby Bauer disc diffusion method. Inducible resistance to clindamycin in S. aureus was tested by 'D test' as per CLSI guidelines. RESULTS: Twenty (10%) isolates showed inducible clindamycin resistance, 18 (9%) showed constitutive resistance while remaining 16 (8%) showed MS phenotype. Inducible resistance and constitutive resistance were found to be higher in MRSA as compared to MSSA (20%, 16% and 6%, 6%, respectively). CONCLUSION: Clindamycin is kept as a reserve drug and is usually advocated in severe MRSA infections depending upon the antimicrobial susceptibility results. This study showed that D test should be used as a mandatory method in routine disc diffusion testing to detect inducible clindamycin resistance in Staphylococci for the optimum treatment of patients.

Bacteriologic profile and antibiogram of blood culture isolates in a pediatric care unit.

UNLABELLED: BACKGROUND / AIMS: Septicemia is one of the important causes of mortality and morbidity in neonates and children. Blood culture is the gold standard for the diagnosis. Emergence of multidrug resistant bacterial strains is a major problem in the management of sepsis. Present study was undertaken to identify the common bacterial pathogens associated with pediatric sepsis and to determine their antibiotic susceptibility pattern. MATERIALS AND METHODS: Blood cultures from 185 suspected cases of sepsis were examined. The growths from the subcultures were identified by conventional biochemical tests. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disk diffusion method and drug resistant strains in primary screening were further processed for extended spectrum beta lactamases (ESBL) and methicillin resistant Staphylococcus aureus (MRSA) status by combination disk method (ESBL) and oxacillin disk diffusion method (MRSA). RESULTS: Out of the 185 cultures obtained from suspected cases, 81 (44%) were culture positive. Fifty-two (35%) of the culture isolates were Gram negative bacilli. Twenty-eight (64%) of the isolates were Gram positive cocci. One case was of mixed infection. The prevalence of MRSA in 41 strains of S. aureus was found to be 29% (12 strains). The overall prevalence of ESBL producers among 28 Gram negative bacterial isolates was found to be 32% (9 strains). CONCLUSION: This study stresses the need for the continuous screening and surveillance for antibiotic resistance in pediatric care unit.