Investigation of Resistance and Clonal Relatedness Among The Nosocomial Acinetobacter Isolates
Abstract
Objective: This study focused on Acinetobacter spp. that were isolated from inpatients to determine the resistance rates to antibiotics and to monitor the resistance increase over the years.
Method: To determine whether there was a clonal relationship between the strains using pulsed field gel electrophoresis (PFGE), to evaluate the epidemiological and clinical data of patients, and to determine the factors that may be effective in the formation and spread of infection, antibiotic susceptibilities of Acinetobacter strains were evaluated by the Kirby Bauer disk diffusion method. Molecular typing was studied with PFGE.
Results: Netilmicin had the least resistance (7%) among the strains, while the highest resistance was found against piperacillin (92%), ceftriaxone (81%), and doxycycline (69%). When resistance profiles of strains were compared according to year (2005-2007), no significant changes were found for resistance rates to piperacillin, ceftriaxone, gentamicin, doxycycline, and trimethoprim / sulfamethoxazole. Of all the 131 tested Acinetobacter spp., 82 (62.6%) of the strains were clustered with the PFGE method and 72.3% of the strains were clonally related. The increase in MDR, XDR and PDR rates among the isolated Acinetobacter spp. is remarkable. It was determined that the degree of transmission of the strains was quite high among patients. The clone in the hospital was able to remain in the environment for long periods and the general patient mortality rates were higher than other studies.
Conclusions: According to results and with the support of molecular typing studies, the need for more effective prevention and control measures in our hospital was demonstrated.
Keywords
References
- Aber CR, Mackel DC. Epidemiologic typing of nosocomial microorganisms. The American Journal of Medicine. 1981;70:898–905.
- Aparajita Richard V, Goering Shabbir S, Foley SL, Zervos M. Application of Molecular Techniques to the Study of Hospital Infection. Clinical Microbiology. 2006;19:512- 530.
- Arbeit RD. Laboratory procedures for the epidemiologic analysis of microorganisms1995., p. 190–208. In Murray PR, Baron EJ, Pfaller MA, Tenover FC, Yolken RH (ed.), Manual of clinical microbiology, 6th ed. American Society for Microbiology, Washington, D.C.
- Beck-Sague CM, Jarvis WR, Brook JH, Culver DH, Potts A, Gay A et al. Epidemic bacteremia due to Acinetobacter baumannii in five intensive care unit. American Journal of Epidemiology. 1990;132:723–733.
- Bergogne-Berezin E, Towner KJ. Acinetobacter spp.as nosocomial pathogens: microbiological, clinical, and epidemilogical features. Clinical Microbiology Review. 1996;9:148–165.
- Bou G, Cervero G, Dominguez MA, Querada C, Martínez-Beltrána J. PCR-based DNA fingerprinting(REP-PCR, AP-PCR) and pulsed-field gel electrophoresis characterization of a nosocomial outbreak caused by imipenem and meropenem- resistant Acinetobacter baumannii. Clinical Microbiology and Infection. 2000;6:635–643.
- Buxton AE, Anderson RL, Werdegar D, Ernest Atlas MD. Nosocomial respiratory tract infection and colonization with Acinetobacter calcoaceticus. The American Journal of Medicine. 1978;65:507–513.
- Catchpole CR, Andrews JM, Brenwald N, Wise R. A reassessment of the in-vitro activity of colistin sulphomethate sodium. Journal of Antimicrobial Chemotheraphy. 1997;39:255–60.
- Clinical and Laboratory Standards Institute 2008. Performance standart for antimicrobial disk susceptibility Testing; Approved standard M2-A9 and M7-A7, 18 th ed. CLSI, Wayne, PA.
- Corbella X, Pujol M, Ayast J, Sendra M, Ardanury C, Dominguez MA, Linares J, Ariza J, Gudiol F. Relevance of digestive tract colonization in the epidemiology of nasocomial infections due to multi resistant Acinetobacter baumannii. Clinical Microbiology and Infectious Disease. 1996;23:329–334.