Nataraj G, Baveja S

Bioline International

Indian J Dermatol Venereol Leprol November-December 2003 Vol 69 Issue 6375CMYK375CommentaryCutaneous bacterial infections: Changing trends in bacterial resistanceGita Nataraj, Sujata BavejaDepar tment of Microbiology, Se th G. S. Medical College & K. E. M. Hospital, Mumbai, India.Address for correspondence: Dr. Gita Nataraj, Department of Microbiology, Seth G. S. Medical College & K. E. M. Hospital, Parel, Mumbai -400012, India. E-mail: nataraj_gita@hotmail.comHow to cite this article: Nataraj G, Baveja S. Cutaneous bacterial infections: Changing trends in bacterial resistance. Indian J DermatolVenereol Leprol 2003;69:375-6.Paper Received: November, 2003. Paper Accepted: December, 2003. Source of Support: Nil.Normal skin is colonized with resident bacterial flora,usually Staphylococcus epidermidis, other coagulase-negative Staphylococci, Corynebacteria and Propionibac-terium acnes. These bacteria form a protective layer andprevent the adhesion and multiplication of potentialpathogens.Cutaneous infections arise whenever there is a breakin the continuity of the skin or as a part of systemicinfection. The spectrum of bacteria associated withprimary cutaneous infections has remained the sameover the years though the frequency of their associa-tion has changed. Staphylococcus aureus, Streptococci,Corynebacterium spp, Erysipelothrix, Enterobacteriaeceae,Pseudomonas and anaerobes have been implicated in avariety of cutaneous infections with polymicrobial in-fections also being reported. The aerobic Gram-posi-tive cocci accounted for more than 60% of cutaneousinfections in the 70’s. Though Staphylococcus aureuscontinues to be the predominant pathogen, Enterobac-teriaeceae, Pseudomonas and Enterococci are being in-creasingly reported.1,2 This spectrum is seen even in HIV-infected patients and intravenous drug users.3-5Infections caused by antibiotic resistant strains havebecome a global problem. The increasing prevalenceof multi-drug resistant organisms with few or notreatment options such as methicillin resistantStaphylococcus aureus (MRSA), vancomycin resistantenterococci (VRE) and the extended spectrum beta-lactamase (ESBL) producing Gram-negative bacilli bothin hospitalized patients and, to a lesser extent, in thecommunity are a serious cause for concern. This trendin antibiotic resistant strains is true for infection atany site of the body.In order of frequency, Staphylococcus aureus accountsfor 30-50% of skin and soft tissue infections, followedby the Enterobacteriaeceae, non-fermenters, Streptococci(beta-hemolytic Group A and others) and anaerobes.6,7On an average more than 90% of Staphylococcus aureuselaborate penicillinases or beta-lactamases (a trendseen even in community acquired strains) and 20-30%of Staphylococcus aureus are methicillin resistant.8 Theprevalence of MRSA in India is also on the rise and thereare reports of detecting MRSA in community-acquiredinfections though the prevalence is much lesser.9,10MRSA strains also demonstrate a high degree ofresistance to other antibiotics especially beta-lactams,erythromycin and aminoglycosides. This changing trendcalls for changes in empirical therapy based on currentsusceptibility patterns. Beta-lactams or erythromycincannot be considered as the standard treatment optionstoday, especially in hospitalized patients. Acombination of beta-lactam/beta-lactamase inhibitor(amoxycillin/clavulanic acid, ampicillin/sulbactum) willelicit a better response. Vancomycin is considered asthe drug of choice for the treatment of infection dueIndian J Dermatol Venereol Leprol November-December 2003 Vol 69 Issue 6 376376 CMYKto MRSA but not for carriage or colonization.8 Favorableoutcomes have also been reported with the use ofteichoplanin and linezolid (an oxyzolidinone). Localeradication is usually achieved with mupirocin,bacitracin or chlorhexidine.Though there are no reports of penicillin resistantStreptococcus pyogenes,  these organisms aredemonstrating increasing tolerance to this antibiotic.ESBLs are beta-lactamases that hydrolyze extended-spectrum cephalosporins with an oxyimino side chain.These cephalosporins include cefotaxime, ceftriaxone,and ceftazidime, as well as the oxyimino-monobactamaztreonam.11 Between 10% and 60% ofenterobacteriaeceae associated with skin and softtissue infections have been reported as ESBLproducers.1,2,6,7 Beta-lactamase inhibitors such asclavulanate, sulbactam or tazobactam in vitro inhibitmost ESBLs, but the clinical effectiveness of beta-lactam/beta-lactamase inhibitor combinations cannotbe relied on consistently for therapy. In fact, thetherapy of choice for infections caused by ESBL-producing members of the Enterobacteriaceae  is acarbapenem.11The presence of open skin lesions in hospitalizeddermatology patients predisposes them to colonizationwith resistant organisms, which, if not adequately caredfor, may lead to infection. The time is therefore aptnot only to treat the infection and eradicate thecolonization or carriage but also to educate the patientat the time of discharge about the appropriate use ofantibiotics and proper wound care. This will reducethe chances of dissemination of resistant pathogens inthe community.It is widely acknowledged that the rapidity ofdevelopment of resistance to an agent increases withthe magnitude of its use. Therefore newer agentsshould be used judiciously only on isolation of aresistant pathogen from definite infection and not fortreatment of colonization or contamination.Thus the antimicrobial options for treatment ofcutaneous infections have undergone a sea change. Inchoosing the appropriate antimicrobial therapy, onemust take into account the resistance profile of theinfective agent, the antibacterial profile of theantimicrobial agent and its pharmacokinetic properties.A combination of beta-lactam/beta-lactamase inhibitormay be a better option in community acquiredinfections, whereas in hospitalized patients culturesensitivity reports will be essential to decide on therapy.REFERENCES1. Rennie RP, Jones RN, Mutrick AH. Occurrence and antimicrobialsusceptibility patterns of pathogens isolated from skin andsoft tissue. Diagn Microbiol Infect Dis 2003;45:287-93.2. Mohanty S, Kapil A, Dhawan B, Das BK. Bacteriological andantimicrobial susceptibility profile of soft tissue infectionsfrom Northern India. Indian J Med Sci 2004;58:10-5.3. Manfredi R, Calza L, Chiodo F. Epidemiology and microbiologyof cellulitis and bacterial soft tissue infection during HIVdisease: A 10-year survey. J Cutan Pathol 2002;29:168-72.4. Bar A, Hantschke D, Mirmohammadsadegh A, Hengge UR.Spectrum of bacterial isolates in HIV-positive patients withskin and sof t tissue infections: emergence of methicillin-resistant staphylococci. AIDS 2003;17:1253-6.5. Summanen PH, Talan DA, Strong C, McTeague M, Bennion R,Thompson JE Jr, et al. Bacteriology of skin and soft-tissueinfections: Comparison of infections in intravenous drug usersand individuals with no history of intravenous drug use. ClinInfect Dis 1995;20:S279-82.6. Gales AC, Jones RN, Pfaller MA, Gordon KA, Sader HS. Twoyear assessment of pathogen frequency and antimicrobialresistance pattern among organisms isolated from skin andsoft tissue infections in Latin American hospitals: results fromthe sentry antimicrobial surveillance programme, 1997-98,SENTRY study group. Int J Infect Dis 2000;4:75-84.7. Doern GV, Jones RN, Pfaller MA, Kugler KC, Beach ML. Bacterialpathogens isolated from patients with skin and sof t tissueinfections: frequency of occurrence and antimicrobialsusceptibility pattern from the SENTRY antimicrobialsurveillance programme, (US and Canada 1997), SENTRY studygroup (North America). Diagn Microbiol Infect Dis 1999;34:65-72.8. Simor AE. Containing methicillin-resistant S. aureus.Surveillance, control, and treatment methods. Postgrad Med2001;110:43-8.9. Pulimood TB, Lalitha MK, Jesudason MV, Pandian R, Selwyn J,Jacob T. The spectrum of antimicrobial resistance amongmethicillin resistant Staphylococcus aureus in a tertiary carecenter in India. Indian J Med Res 1996;103:212-5.10. Saxena S, Singh K, Talwar V. Methicillin-resistant Staphylococcusaureus prevalence in community in the east Delhi area. Jpn JInfect Dis 2003;56:54-6.11. Paterson DL, Ko WC, von Gottberg A, Casellas JM, MulazimogluL, Klugman KP, et al. Outcome of cephalosporin treatment forserious infections due to apparently susceptible organismsproducing extended-spectrum beta-lactamases: implicationsfor the clinical microbiology laboratory. J Clin Microbiol2001;39:2206-12.Nataraj G, et al: Cutaneous bacterial infections

Cutaneous bacterial infections: Changing trends in bacterial resistance

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