Journal of Global Infectious Diseases

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 11  |  Issue : 3  |  Page : 112--117

Biofilm formation of methicillin-resistant coagulase-negative staphylococci isolated from clinical samples in Northern Thailand


Thawatchai Kitti1, Rathanin Seng2, Rapee Thummeepak3, Chalermchai Boonlao4, Thanyasiri Jindayok5, Sutthirat Sitthisak6 
1 Department of Microbiology and Parasitology, Faculty of Oriental Medicine, Chiang Rai College, Bangkok, Thailand
2 Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
3 Department of Microbiology and Parasitology, Faculty of Medical Sciences, Naresuan University, Chiang Rai, Thailand
4 Department Clinical Microbiology, Chiangrai Prachanukroh Hospital, Chiang Rai, Thailand
5 Division of Clinical Pathology, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand
6 Department of Microbiology and Parasitology, Faculty of Medical Sciences, Naresuan University, Chiang Rai; Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand

Correspondence Address:
Dr. Sutthirat Sitthisak
Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok
Thailand

Background: Methicillin-resistant coagulase-negative staphylococci (MR-CoNS) are multidrug-resistant bacteria that are difficult to treat because of their ability to form biofilms. Objectives: In the present study, we evaluated the antibiotic-resistant phenotypes, biofilm-forming ability, and biofilm associated genes of 55 clinical MR-CoNS isolates obtained from two hospitals in Thailand. Materials and Methods: MALDI-TOF-MS and tuf gene sequencing were performed to determine the species of all isolates. Biofilm production was determined using Congo red agar (CRA) and the microtiter plate (MTP) assay. Biofilm-associated genes were characterized using polymerase chain reaction (PCR). Results: Among the 55 MR-CoNS isolates, five species were identified as Staphylococcus haemolyticus (34.5%), Staphylococcus epidermidis (32.7%), Staphylococcus capitis (18.2%), Staphylococcus cohnii (9.1%), and Staphylococcus hominis (5.5%). The antimicrobial susceptibility pattern of MR-CoNS isolates indicated high resistance to cefoxitin (100%), penicillin (98.2%), erythromycin (96.4%), ciprofloxacin (67.3%), sulfamethoxazole/trimethoprim (67.3%), gentamicin (67.3%), and clindamycin (63.6%). All the isolates were susceptible to vancomycin and linezolid. The biofilm production was detected in 87.3% isolates through the CRA method and in 38.1% isolates through the MTP assay. The prevalence rates of ica AD, bap, fnb A, and cna were 18.2%, 12.7%, 47.3%, and 27.3%, respectively. There were significant differences in the presence of these biofilm-associated genes among the MR-CoNS isolates. Moreover, quantitative biofilm formation was significantly different among MR-CoNS species. Conclusion: The present study revealed that biofilm-associated genes are important for biofilm biomass in MR-CoNS isolates, and the findings of this study are essential for finding new strategies to control biofilm formation and prevent the spread of MR-CoNS infectious diseases.


How to cite this article:
Kitti T, Seng R, Thummeepak R, Boonlao C, Jindayok T, Sitthisak S. Biofilm formation of methicillin-resistant coagulase-negative staphylococci isolated from clinical samples in Northern Thailand.J Global Infect Dis 2019;11:112-117


How to cite this URL:
Kitti T, Seng R, Thummeepak R, Boonlao C, Jindayok T, Sitthisak S. Biofilm formation of methicillin-resistant coagulase-negative staphylococci isolated from clinical samples in Northern Thailand. J Global Infect Dis [serial online] 2019 [cited 2020 Apr 5 ];11:112-117
Available from: http://www.jgid.org/article.asp?issn=0974-777X;year=2019;volume=11;issue=3;spage=112;epage=117;aulast=Kitti;type=0