[Downloaded free from http://www.ijmm.org on Saturday, June 13, 2015, IP: 61.16.135.116]
Indian Journal of Medical Microbiology, (2015) 33(3): 413-415
Brief Communication
Fluconazole susceptibility of 3,056 clinical isolates of Candida species from 2005 to 2009 in a tertiary-care hospital Y Ying, J Zhang, SB Huang, FD Liu, JH Liu, J Zhang, XF Hu, ZQ Zhang, X Liu, *XT Huang
Abstract In recent years, Candida infections have been increasing significantly. This study was to investigate the distribution and fluconazole susceptibility of such infections. Totally, 3,056 clinical isolates were analysed, C. albicans was the most prevalent species from respiratory and vaginal specimens. However, non-albicans species constituted the majority of isolates from blood, urine, intensive care unit (ICU), organ transplant and burned patients. Similarly, Candida spp. from different specimens and clinical services had different degrees of susceptibility to fluconazole. Isolates from vagina and burned patients had the highest resistance rate, while all of the isolates from ascites and dermatological services were susceptible to fluconazole. Key words: Candida, epidemiology, fluconazole, susceptibility
Introduction Candida species are the most prevalent fungal pathogens. Recently, the incidence infections has been increased because of suppression and frequent broad-spectrum therapy.[1,2]
opportunistic of Candida the immune antibacterial
Most cases of Candida infections are caused by C. albicans, but those caused by non-albicans species of Candida, such as C. glabrata, C. tropicalis and C. krusei, appear to be rising.[1,3] In addition, the widespread and long-time use of azoles has resulted in resistance to azoles.[4] The increased incidence of acquired resistance to azoles and the shift from C. albicans to non-albicans species may pose serious problems in the management of infections;thus, it is *Corresponding author (email: ) Department of Medical Microbiology (YY, JZ, JHL, JZ, ZQZ, XL, XTH), School of Medicine, Department of Clinical Laboratory (XFH), The First Affiliated Hospital of Nanchang University, Department of Pharmacy (SBH), Medical College, Nanchang University, Nanchang, Department of Clinical Laboratory (FDL), Children’s Hospital of Jiangxi Province, Nanchang, People's Republic of China Received: 04-09-2013 Accepted: 13-01-2015 Access this article online Quick Response Code:
Website: www.ijmm.org PMID: *** DOI: 10.4103/0255-0857.158569
necessary to identify Candida spp. in clinical settings and monitor their antifungal resistance for providing appropriate treatment for candidasis. To this end, we retrospectively investigated 3,056 isolates of clinical Candida spp. at the First Affiliated Hospital of Nanchang University over a 4-year period. Materials and Methods From January 2005 to July 2009, a total of 3,056 isolates of Candida spp. were obtained from patients with Candida infections. These isolates were identified by using CHROMagar plates and a Vitek 2 system. C. krusei ATCC 6258 and C. parapsilosis ATCC 22019 were used as quality control reference strains. Fluconazole susceptibility was tested according to the M27-A2 broth microdilution method, as recommended by the clinical and laboratory standards institute (CLSI) (formerly NCCLS). All isolates were passed through two successive subcultures (first 48 hours and then 24 hours) on sabouraud agar (SDA) at 35°C to ensure viability and purity. Suspensions were prepared in sterile 0.85% saline and were adjusted to match the turbidity of a 0.5 McFarland standard at 530 nm wavelength. Then, the stock suspension was diluted 1:50 and further diluted 1:20 with Rosewell Park Memorial Institute (RPMI) 1640 broth medium, which result in 1.0 × 103 to 5 × 103 CFU/mL. Finally, 100 µL suspension was inoculated into each well on 96-well microplates containing 100 µL of antifungal agent and incubated at 35°C for 48 hours. The minimum inhibitory concentration (MIC) for fluconazole was defined as the lowest concentration that caused a decrease in turbidity, which corresponded to approximately 50% of the inhibition in a growth control well. According to the CLSI M27-A2 standard, isolates with MICs ≤8 ug/ml, between 16 and
[Downloaded free from http://www.ijmm.org on Saturday, June 13, 2015, IP: 61.16.135.116]
414
Indian Journal of Medical Microbiology
32 ug/ml and ≥64 ug/m were considered susceptible, susceptible dose-dependent (S-DD) and resistant to fluconazole, respectively. Results Among 3,056 clinical isolates, 2,170 (71.0%) isolates were identified as C. albicans, followed by C. glabrata (547, 17.9%), C. tropicalis (155, 5.1%), C. krusei (114, 3.7%), C. parapsilosis (17, 0.6%) and other Candida species (53, 1.7%). Overall, 87.7% Candida isolates were susceptible to fluconazole. The resistance rate of C. albicans, C. glabrata, C. tropicalis and C. krusei was 4.3%, 5.7%, 7.1% and 100%, respectively. The Candida spp. isolates were collected from various clinical specimen types, including blood, urine, ascites, faecal, respiratory tract and vaginal tract specimens as shown in Table 1, C. albicans constituted more than 65.0% of isolates from the respiratory (77.0%) and vaginal (67.0%) tract specimens. C. glabrata constituted 40.9% and 33.0% of all Candida spp. from blood and urine, respectively. C. tropicalis accounted for 12.7% of all urinary tract isolates of Candida but was less common (
Indian Journal of Medical Microbiology, (2015) 33(3): 413-415
Brief Communication
Fluconazole susceptibility of 3,056 clinical isolates of Candida species from 2005 to 2009 in a tertiary-care hospital Y Ying, J Zhang, SB Huang, FD Liu, JH Liu, J Zhang, XF Hu, ZQ Zhang, X Liu, *XT Huang
Abstract In recent years, Candida infections have been increasing significantly. This study was to investigate the distribution and fluconazole susceptibility of such infections. Totally, 3,056 clinical isolates were analysed, C. albicans was the most prevalent species from respiratory and vaginal specimens. However, non-albicans species constituted the majority of isolates from blood, urine, intensive care unit (ICU), organ transplant and burned patients. Similarly, Candida spp. from different specimens and clinical services had different degrees of susceptibility to fluconazole. Isolates from vagina and burned patients had the highest resistance rate, while all of the isolates from ascites and dermatological services were susceptible to fluconazole. Key words: Candida, epidemiology, fluconazole, susceptibility
Introduction Candida species are the most prevalent fungal pathogens. Recently, the incidence infections has been increased because of suppression and frequent broad-spectrum therapy.[1,2]
opportunistic of Candida the immune antibacterial
Most cases of Candida infections are caused by C. albicans, but those caused by non-albicans species of Candida, such as C. glabrata, C. tropicalis and C. krusei, appear to be rising.[1,3] In addition, the widespread and long-time use of azoles has resulted in resistance to azoles.[4] The increased incidence of acquired resistance to azoles and the shift from C. albicans to non-albicans species may pose serious problems in the management of infections;thus, it is *Corresponding author (email: ) Department of Medical Microbiology (YY, JZ, JHL, JZ, ZQZ, XL, XTH), School of Medicine, Department of Clinical Laboratory (XFH), The First Affiliated Hospital of Nanchang University, Department of Pharmacy (SBH), Medical College, Nanchang University, Nanchang, Department of Clinical Laboratory (FDL), Children’s Hospital of Jiangxi Province, Nanchang, People's Republic of China Received: 04-09-2013 Accepted: 13-01-2015 Access this article online Quick Response Code:
Website: www.ijmm.org PMID: *** DOI: 10.4103/0255-0857.158569
necessary to identify Candida spp. in clinical settings and monitor their antifungal resistance for providing appropriate treatment for candidasis. To this end, we retrospectively investigated 3,056 isolates of clinical Candida spp. at the First Affiliated Hospital of Nanchang University over a 4-year period. Materials and Methods From January 2005 to July 2009, a total of 3,056 isolates of Candida spp. were obtained from patients with Candida infections. These isolates were identified by using CHROMagar plates and a Vitek 2 system. C. krusei ATCC 6258 and C. parapsilosis ATCC 22019 were used as quality control reference strains. Fluconazole susceptibility was tested according to the M27-A2 broth microdilution method, as recommended by the clinical and laboratory standards institute (CLSI) (formerly NCCLS). All isolates were passed through two successive subcultures (first 48 hours and then 24 hours) on sabouraud agar (SDA) at 35°C to ensure viability and purity. Suspensions were prepared in sterile 0.85% saline and were adjusted to match the turbidity of a 0.5 McFarland standard at 530 nm wavelength. Then, the stock suspension was diluted 1:50 and further diluted 1:20 with Rosewell Park Memorial Institute (RPMI) 1640 broth medium, which result in 1.0 × 103 to 5 × 103 CFU/mL. Finally, 100 µL suspension was inoculated into each well on 96-well microplates containing 100 µL of antifungal agent and incubated at 35°C for 48 hours. The minimum inhibitory concentration (MIC) for fluconazole was defined as the lowest concentration that caused a decrease in turbidity, which corresponded to approximately 50% of the inhibition in a growth control well. According to the CLSI M27-A2 standard, isolates with MICs ≤8 ug/ml, between 16 and
[Downloaded free from http://www.ijmm.org on Saturday, June 13, 2015, IP: 61.16.135.116]
414
Indian Journal of Medical Microbiology
32 ug/ml and ≥64 ug/m were considered susceptible, susceptible dose-dependent (S-DD) and resistant to fluconazole, respectively. Results Among 3,056 clinical isolates, 2,170 (71.0%) isolates were identified as C. albicans, followed by C. glabrata (547, 17.9%), C. tropicalis (155, 5.1%), C. krusei (114, 3.7%), C. parapsilosis (17, 0.6%) and other Candida species (53, 1.7%). Overall, 87.7% Candida isolates were susceptible to fluconazole. The resistance rate of C. albicans, C. glabrata, C. tropicalis and C. krusei was 4.3%, 5.7%, 7.1% and 100%, respectively. The Candida spp. isolates were collected from various clinical specimen types, including blood, urine, ascites, faecal, respiratory tract and vaginal tract specimens as shown in Table 1, C. albicans constituted more than 65.0% of isolates from the respiratory (77.0%) and vaginal (67.0%) tract specimens. C. glabrata constituted 40.9% and 33.0% of all Candida spp. from blood and urine, respectively. C. tropicalis accounted for 12.7% of all urinary tract isolates of Candida but was less common (
