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Antimicrobial susceptibility data for Brucella melitensis isolates cultured from UK patients
Letters to the Editor Antimicrobial susceptibility data for Brucella melitensis isolates cultured from UK patients
Dear Editor, For the treatment of brucellosis, the World Health Organisation (WHO) recommends only a limited number of antibiotics with good intracellular penetration and proven clinical efficiency.1 Generally, Brucella species are considered susceptible to the WHO recommended antibiotics through sporadic cases of antimicrobial resistance occur.2,3 Sensitivity testing is infrequently performed due to concerns over laboratory-acquired infection and the need for containment level 3 facilities. However, in-vitro susceptibilities can vary across geographical regions.4,5 Furthermore, until recently invitro susceptibility testing of Brucella spp has not been standardised. Currently, the UK’s British Society of Antimicrobial Chemotherapy and the European Committee on Antimicrobial Susceptibility Testing have not published interpretative breakpoints for brucella antimicrobial sensitivities. As a consequence there are no antimicrobial susceptibility data for Brucella spp cultured from UK patients. We therefore report a prospective study of in-vitro sensitivities to commonly used anti-brucella antibiotic agents. Since 2011, Brucella spp referred to the Brucella Biohazard Facility, Animal Health and Veterinary Agency, for confirmatory identification have routinely undergone antimicrobial sensitivity testing to tetracycline (TET), rifampicin (RIF), ciprofloxacin (CIP), streptomycin (STREP) and gentamicin (GENT) by E-test methodology (Biomerieux, Sweden). The minimum inhibitory concentration (MIC) was interpreted as the value at which the inhibition zone intercepted the scale on the E-strip. MIC90 was defined as the lowest concentration of an antibiotic at which 90% of isolates were inhibited. Clinical Laboratory Standards Institute sensitivity breakpoints (mg/L) were employed for TET (<1), RIF (2) and STREP (8).6 For CIP and GENT, breakpoints were set at 2 based on previously published data.7,8 Seventeen Brucella melitensis isolates were examined. MIC90 values (mg/l) for TET, RIF, CIP, STREP and GENT were 0.064, 1.0, 0.25, 1.0 and 0.25 respectively. Tetracycline was found to be the most active agent followed by CIP/GENT and then RIF/STREP. No antimicrobial resistant strains were identified. Brucellosis is an uncommon infection in the UK and is typically acquired from countries where there is an endemic problem. This is the first UK study that has examined the antimicrobial sensitivity patterns of B. melitensis isolates cultured from UK patients. The WHO considers tetracycline and its derivatives to be one of the most effective antimicrobials against brucellosis. This study confirms that view and should provide reassurance to UK clinicians who manage this infection. Though no antimicrobial resistance in UK strains was identified, continued surveillance for the emergence of antimicrobial resistance in brucellosis is justified and is ongoing.
401
References 1. Corbel MJ. Brucellosis in humans and animals, 5. World Health Organisation in collaboration with the Food and Agriculture Organisation of the United Nations and the World Organisation for Animal Health; 2006. pp. 36e40 (WHO/CDS/EPR/2006.7). 2. Baykam N, Esener H, Ergonul O, Eren S, Celikbas AK, Dokuzoguz B. In vitro antimicrobial susceptibility of Brucella species. Int J Antimicrob Agents 2004;23:405e7. pez-Merino A, Contreras-Rodrıguez A, Migranas-Ortiz R, Or3. Lo ndez-Oliva GM, Gutie rrez-Rubio AT, rantia-Gradın R, Herna et al. Susceptibility of Mexican brucella isolates to moxifloxacin, ciprofloxacin and other antimicrobials used in the treatment of human brucellosis. Scand J Infect Dis 2004;36:636e8. 4. De Reutlin de la Roy YM, Grignon B, Grollier G, Coindreau MF, Becq-Giraudon B. Rifampicin resistance in a strain of Brucella melitensis after treatment with doxycycline and rifampicin. J Antimicrob Chemother 1986;18:648e9. 5. Kinsara A, Al-Mowalled A, Osoba AO. Increasing resistance of Brucellae to co-trimoxazole. Antimicrob Agents Chemother 1999;43:153. 6. Clinical and Laboratory Standards Institute. Performance for antimicrobial susceptibility testing, seventeenth informational supplement, 26. Wayne PA, USA: CLSI; 2007. pp. 1e182. CLSI document M100-517. 7. Falagas ME, Bliziotis IA. Quinolones for treatment of human brucellosis: critical review of the evidence from microbiological and clinical studies. Antimicrob Agents Chemother 2006; 50(1):22e33. 8. Roberts NL, Farrell ID, Hinchcliffe PM. The sensitivity of Brucella abortus to chemotherapeutic agents. J Med Microbiol 1973;6:549e57.
R.P.D. Cooke* Brucella Reference Unit, University Hospital Aintree, Liverpool, UK *Corresponding author. Tel.: þ44 0151 529 4916; fax: þ44 0151 529 4918. L. Perrett Brucella Biohazard Faculty, Animal Health and Veterinary Agency, Surrey, UK E-mail address: [email protected] Accepted 11 January 2014 ª 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jinf.2014.01.002
The rise and fall of mandatory surveillance for glycopeptide-resistant enterococcal bacteraemia in England
Dear Editor, We read with interest the report by Mikulska and colleagues revealing a heterogeneous but rising incidence
Dear Editor, For the treatment of brucellosis, the World Health Organisation (WHO) recommends only a limited number of antibiotics with good intracellular penetration and proven clinical efficiency.1 Generally, Brucella species are considered susceptible to the WHO recommended antibiotics through sporadic cases of antimicrobial resistance occur.2,3 Sensitivity testing is infrequently performed due to concerns over laboratory-acquired infection and the need for containment level 3 facilities. However, in-vitro susceptibilities can vary across geographical regions.4,5 Furthermore, until recently invitro susceptibility testing of Brucella spp has not been standardised. Currently, the UK’s British Society of Antimicrobial Chemotherapy and the European Committee on Antimicrobial Susceptibility Testing have not published interpretative breakpoints for brucella antimicrobial sensitivities. As a consequence there are no antimicrobial susceptibility data for Brucella spp cultured from UK patients. We therefore report a prospective study of in-vitro sensitivities to commonly used anti-brucella antibiotic agents. Since 2011, Brucella spp referred to the Brucella Biohazard Facility, Animal Health and Veterinary Agency, for confirmatory identification have routinely undergone antimicrobial sensitivity testing to tetracycline (TET), rifampicin (RIF), ciprofloxacin (CIP), streptomycin (STREP) and gentamicin (GENT) by E-test methodology (Biomerieux, Sweden). The minimum inhibitory concentration (MIC) was interpreted as the value at which the inhibition zone intercepted the scale on the E-strip. MIC90 was defined as the lowest concentration of an antibiotic at which 90% of isolates were inhibited. Clinical Laboratory Standards Institute sensitivity breakpoints (mg/L) were employed for TET (<1), RIF (2) and STREP (8).6 For CIP and GENT, breakpoints were set at 2 based on previously published data.7,8 Seventeen Brucella melitensis isolates were examined. MIC90 values (mg/l) for TET, RIF, CIP, STREP and GENT were 0.064, 1.0, 0.25, 1.0 and 0.25 respectively. Tetracycline was found to be the most active agent followed by CIP/GENT and then RIF/STREP. No antimicrobial resistant strains were identified. Brucellosis is an uncommon infection in the UK and is typically acquired from countries where there is an endemic problem. This is the first UK study that has examined the antimicrobial sensitivity patterns of B. melitensis isolates cultured from UK patients. The WHO considers tetracycline and its derivatives to be one of the most effective antimicrobials against brucellosis. This study confirms that view and should provide reassurance to UK clinicians who manage this infection. Though no antimicrobial resistance in UK strains was identified, continued surveillance for the emergence of antimicrobial resistance in brucellosis is justified and is ongoing.
401
References 1. Corbel MJ. Brucellosis in humans and animals, 5. World Health Organisation in collaboration with the Food and Agriculture Organisation of the United Nations and the World Organisation for Animal Health; 2006. pp. 36e40 (WHO/CDS/EPR/2006.7). 2. Baykam N, Esener H, Ergonul O, Eren S, Celikbas AK, Dokuzoguz B. In vitro antimicrobial susceptibility of Brucella species. Int J Antimicrob Agents 2004;23:405e7. pez-Merino A, Contreras-Rodrıguez A, Migranas-Ortiz R, Or3. Lo ndez-Oliva GM, Gutie rrez-Rubio AT, rantia-Gradın R, Herna et al. Susceptibility of Mexican brucella isolates to moxifloxacin, ciprofloxacin and other antimicrobials used in the treatment of human brucellosis. Scand J Infect Dis 2004;36:636e8. 4. De Reutlin de la Roy YM, Grignon B, Grollier G, Coindreau MF, Becq-Giraudon B. Rifampicin resistance in a strain of Brucella melitensis after treatment with doxycycline and rifampicin. J Antimicrob Chemother 1986;18:648e9. 5. Kinsara A, Al-Mowalled A, Osoba AO. Increasing resistance of Brucellae to co-trimoxazole. Antimicrob Agents Chemother 1999;43:153. 6. Clinical and Laboratory Standards Institute. Performance for antimicrobial susceptibility testing, seventeenth informational supplement, 26. Wayne PA, USA: CLSI; 2007. pp. 1e182. CLSI document M100-517. 7. Falagas ME, Bliziotis IA. Quinolones for treatment of human brucellosis: critical review of the evidence from microbiological and clinical studies. Antimicrob Agents Chemother 2006; 50(1):22e33. 8. Roberts NL, Farrell ID, Hinchcliffe PM. The sensitivity of Brucella abortus to chemotherapeutic agents. J Med Microbiol 1973;6:549e57.
R.P.D. Cooke* Brucella Reference Unit, University Hospital Aintree, Liverpool, UK *Corresponding author. Tel.: þ44 0151 529 4916; fax: þ44 0151 529 4918. L. Perrett Brucella Biohazard Faculty, Animal Health and Veterinary Agency, Surrey, UK E-mail address: [email protected] Accepted 11 January 2014 ª 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jinf.2014.01.002
The rise and fall of mandatory surveillance for glycopeptide-resistant enterococcal bacteraemia in England
Dear Editor, We read with interest the report by Mikulska and colleagues revealing a heterogeneous but rising incidence