Indian Journal of Medical Microbiology Medknow Publications on behalf of Indian Association of Medical Microbiology ISSN: 0255-0857 EISSN: 1998-3646 Vol. 27, Num. 1, 2009, pp. 89-89

Indian Journal of Medical Microbiology, Vol. 27, No. 1, January-March, 2009, pp. 89

Correspondence

Prostatic abscess by Staphylococcus aureus in a diabetic patient

Krishna BVS

Lothian University Hospitals Division, Royal Infirmary of Edinburgh, 51, Little France Crescent, Edinburgh, EH16 4SA
Correspondence Address:Lothian University Hospitals Division, Royal Infirmary of Edinburgh, 51, Little France Crescent, Edinburgh, EH16 4SA, bvsk@yahoo.com

Date of Submission: 30-Nov-2008
Date of Acceptance: 01-Jan-2009

Code Number: mb09031

Dear Editor,

I read with interest the article "Prostatic abscess by Staphylococcus aureus in a diabetic patient" ^[1] published in the Oct-Dec 2008 issue of the Indian Journal of Medical Microbiology . The article describes a rare case of prostatic abscess. However, several aspects of the article need to be set in the correct perspective so that the practice of clinical microbiology in India is enriched. Infections with S. aureus are common in diabetics. The prostatic abscess with S. aureus is most probably haematogenous. A blood culture taken from the patient would have been very useful. Prostatic abscess is unlikely to be the primary pathology and the source is likely to be elsewhere (endocarditis, disciitis or osteomyelitis). In any case, these sources or complications need to be ruled out.

Treatment with penicillinase-resistant penicillins (flucloxacillin, cloxacillin or nafcillin) given intravenously is the treatment of choice for S. aureus infections. ^[2] These penicillins concentrate sufficiently in the prostrate in the presence of inflammation to achieve a time-dependent killing. Analysing the pharmacokinetics and pharmacodynamics of ciprofloxacin in S. aureus infections of the prostate, the Cmax/minimum inhibitory concentration (MIC) ratio (the maximal tissue concentration of the drug divided by the MIC) achieved is about 8-20. Being a concentration-dependent drug, ciprofloxacin needs to have a much higher Cmax/MIC ratio to achieve adequate cure. In addition, S. aureus rapidly develops resistance through mutations on ciprofloxacillin monotherapy. ^[3] For these reasons, ciprofloxacin should not be used in the treatment of S. aureus infections.

The authors do not mention the duration of antibiotic treatment. Although the abscess was drained, antibiotics for at least 4 weeks are needed to achieve complete cure. Cefotaxime should not be tested against S. aureus , should not be reported and S. aureus infections should not be treated with it. Reporting wrong antibiotic susceptibilities will only encourage improper use of antibiotics.

References

1.	Baradkar VP, Mathur M, Kumar S. Prostatic abscess by Staphylococcus aureus in a diabetic patient. Indian J Med Microbiol 2008;26:395-7.  Back to cited text no. 1  [PUBMED]
2.	Cosgrove SE. Staphylococcus aureus . In: The Abx guide; Diagnosis and treatment of infectious diseases. 1 st ed. In: Bartlett JG, Auwaerter PG, Pham PA, editors. Thompson PDR, Montvale; 2005. p. 513-5.  Back to cited text no. 2
3.	Livermore DM, Winstanley TG, Shannon KP. Interpretative reading: Recognizing the unusual and inferring resistance mechanism from resistance phenotypes. J Antimicrob Chemother 2001;48:87-102.  Back to cited text no. 3  [PUBMED]  [FULLTEXT]

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