Acute melioidosis may present as localised or septicaemic infections and can be fatal if left untreated. Burkholderia pseudomallei resistant to antibiotics used for the treatment of melioidosis had been reported. The aim of this study was to determine the in vitro antibiotic susceptibility patterns of Burkholderia pseudomallei isolated in Malaysia to a panel of antibiotics used for the treatment of melioidosis and also to potential alternative antibiotics such as tigecycline, ampicillin/sulbactam, and piperacillin/tazobactam. A total of 170 Burkholderia pseudomallei isolates were subjected to minimum inhibitory concentration determination using -test method to eleven antibiotics. All isolates were sensitive to meropenem and piperacillin/tazobactam. For ceftazidime, imipenem, amoxicillin/clavulanic acid, and doxycycline resistance was observed in 1 isolate (0.6%) for each of the antibiotics. Trimethoprim/sulfamethoxazole resistance was observed in 17 (10%) isolates. For other antibiotics, ampicillin/sulbactam, chloramphenicol, tigecycline, and ciprofloxacin resistance were observed in 1 (0.6%), 6 (3.5%), 60 (35.3%) and 98 (57.7%) isolates respectively. One isolate B170/06 exhibited resistance to 4 antibiotics, namely, ciprofloxacin, chloramphenicol, trimethoprim/sulfamethoxazole, and tigecycline. In conclusion, the Malaysian isolates were highly susceptible to the current antibiotics used in the treatment of melioidosis in Malaysia. Multiple resistances to the antibiotics used in the maintenance therapy are the cause for a concern. 1. Introduction The causative agent of melioidosis, Burkholderia pseudomallei, is endemic in the Northern part of Australia and Southeast Asia including Malaysia. Acute melioidosis may present as localized or septicaemic infections and can be fatal if left untreated. It was the common cause of community-acquired pneumonia in Northeastern Thailand and was attributed as the cause of fatal community-acquired bacteremic pneumonia in Northern Australia [1, 2]. Latent infection may remain asymptomatic for years only to be reactivated from a latent focus when the host is immunocompromised. Therefore, it is important to treat melioidosis with prolonged course of antibiotics so as to avoid disease relapses which are commonly associated with short courses of antibiotics. Some patients may default treatment or take improper dosage of antibiotics because of the long duration of treatment, and this may contribute to the relapse or the development of resistance. Burkholderia pseudomallei is intrinsically resistant to a wide range of
References
[1]
W. Chaowagul, N. J. White, D. A. Dance et al., “Melioidosis: a major cause of community-acquired septicemia in northeastern Thailand,” Journal of Infectious Diseases, vol. 159, no. 5, pp. 890–899, 1989.
[2]
M. W. Douglas, G. Lum, J. Roy, D. A. Fisher, N. M. Anstey, and B. J. Currie, “Epidemiology of community-acquired and nosocomial bloodstream infections in tropical Australia: a 12-month prospective study,” Tropical Medicine and International Health, vol. 9, no. 7, pp. 795–804, 2004.
[3]
Ministry of Health Malaysia, National Antibiotic Guidelines Malaysia, Ministry of Health Malaysia, Putrajaya, Malaysia, 2008, http://apps.who.int/medicinedocs/en/m/abstract/Js17800en/.
[4]
C. T. Kung, C. H. Lee, C. J. Li, H. I. Lu, S. F. Ko, and J. W. Liu, “Development of ceftazidime resistance in Burkhoderia pseudomallei in a patient experiencing melioidosis with mediastinal lymphadenitis,” Annals of the Academy of Medicine Singapore, vol. 39, no. 12, pp. 945–947, 2010.
[5]
V. Wuthiekanun, P. Amornchai, N. Saiprom et al., “Survey of antimicrobial resistance in clinical Burkholderia pseudomallei isolates over two decades in Northeast Thailand,” Antimicrobial Agents and Chemotherapy, vol. 55, no. 11, pp. 5388–5391, 2011.
[6]
R. Karunakaran and S. D. Puthucheary, “Burkholderia pseudomallei: in vitro susceptibility to some new and old antimicrobials,” Scandinavian Journal of Infectious Diseases, vol. 39, no. 10, pp. 858–861, 2007.
[7]
I. C. Sam, K. H. See, and S. D. Puthucheary, “Susceptibility of Burkholderia pseudomallei to tigecycline and other antimicrobials,” Diagnostic Microbiology and Infectious Disease, vol. 67, no. 3, pp. 308–309, 2010.
[8]
M. D. Brook, B. Currie, and P. M. Desmarchelier, “Isolation and identification of Burkholderia pseudomallei from soil using selective culture techniques and the polymerase chain reaction,” Journal of Applied Microbiology, vol. 82, no. 5, pp. 589–596, 1997.
[9]
Clinical and Laboratory Standards Institute, Methods for Antimicrobial Dilution and Disk Susceptibility Testing of Infrequently Isolated or Fastidious Bacteria, vol. 30, no 18, Clinical and Laboratory Standards Institute, Wayne, Pa, USA, 2nd edition, M45-A2.
[10]
Clinical and Laboratory Standards Institute, Performance Standards for Antimicrobial Susceptibility Testing; Twenty-Second Informational Supplement M100-S21, vol. 32, no 3, Clinical and Laboratory Standards Institute, Wayne, Pa, USA, 2012.
[11]
A. W. Jenney, G. Lum, D. A. Fisher, and B. J. Currie, “Antibiotic susceptibility of Burkholderia pseudomallei from tropical northern Australia and implications for therapy of melioidosis,” International Journal of Antimicrobial Agents, vol. 17, no. 2, pp. 109–113, 2001.
[12]
D. S. Sarovich, E. P. Price, Limmathurotsakul et al., “Development of ceftazidime resistance in an acute Burkholderia pseudomallei infection,” Infection and Drug Resistance, vol. 5, pp. 129–132, 2012.
[13]
V. Wuthiekanun, A. C. Cheng, W. Chierakul et al., “Trimethoprim/sulfamethoxazole resistance in clinical isolates of Burkholderia pseudomallei,” Journal of Antimicrobial Chemotherapy, vol. 55, no. 6, pp. 1029–1031, 2005.
[14]
W. Chaowagul, W. Chierakul, A. J. Simpson et al., “Open-label randomized trial of oral trimethoprim-sulfamethoxazole, doxycycline, and chloramphenicol compared with trimethoprim-sulfamethoxazole and doxycycline for maintenance therapy of melioidosis,” Antimicrobial Agents and Chemotherapy, vol. 49, no. 10, pp. 4020–4025, 2005.
[15]
P. Chetchotisakd, W. Chaowagul, P. Mootsikapun, D. Budhsarawong, and B. Thinkamrop, “Maintenance therapy of melioidosis with ciprofloxacin plus azithromycin compared with cotrimoxazole plus doxycycline,” American Journal of Tropical Medicine and Hygiene, vol. 64, no. 1-2, pp. 24–27, 2001.
[16]
W. Chaowagul, Y. Suputtamongkul, M. D. Smith, and N. J. White, “Oral fluoroquinolones for maintenance treatment of melioidosis,” Transactions of the Royal Society of Tropical Medicine and Hygiene, vol. 91, no. 5, pp. 599–601, 1997.
[17]
V. Thamlikitkul and S. Trakulsomboon, “In vitro activity of tigecycline against Burkholderia pseudomallei and Burkholderia thailandensis,” Antimicrobial Agents and Chemotherapy, vol. 50, no. 4, pp. 1555–1557, 2006.
[18]
M. Feterl, B. Govan, C. Engler, R. Norton, and N. Ketheesan, “Activity of tigecycline in the treatment of acute Burkholderia pseudomallei infection in a murine model,” International Journal of Antimicrobial Agents, vol. 28, no. 5, pp. 460–464, 2006.
