Résumé
A BACTERIOLOGICAL STUDY OF URINARY TRACT INFECTION INVOLVING CULTURAL ANALYSIS Original Research Paper Estibeiro AS* Associate Professor, Department of Microbiology, Goa Medical College, Bambolim Goa, 403202 *Corresponding Author Background: Urinary Tract Infections are a common occurrence in the community and hospital and are associated with profound morbidity and decreased productivity at work. Timely diagnosis of UTI by cultural analysis is imperative in order to identify the offending agent and to initiate appropriate antimicrobial therapy. Objectives: The present study aimed at evaluating the bacteriological pro?le of UTI employing semiquantitative culture and to determine the antibiogram pattern of the bacteria isolated. The study was conducted on 200 urine samples, collected Methods: from clinically suspected cases of UTI. Semiquantitative analysis was done and antimicrobial sensitivity testing undertaken, as per CLSI guidelines. Signi?cant bacteriuria was observed in 66.5% cases. Gram negative bacilli were Results: predominant pathogens (71.3%), amongst which, Escherichia coli and Klebsiella pneumoniae were the main agents (37.2% and 24.5 % respectively). Gram positive organisms accounted for 28.7% of the total; Enterococcus species being the predominant isolate type (78.04%; 32 out of 41 gram positive pathogens). Overall, Escherichia coli predominated (26.6%), followed by Enterococcus species (22.4%). Gram negative bacilli showed good sensitivity to Imipenem and Aminoglycosides. Gram positive cocci were all sensitive to Vancomycin and Linezolid. A large number of cases were 50 years and above (51%), followed by age groups 21-30 years (17.5%) and 31 to 40 years (16.5%). The Male: Female ratio was 1.2:1, males accounting for 53.5% of the total. Early cultural analysis of UTI cases with identi?cation of the etiological agent and its Conclusion: antibiogram pattern will help in early treatment and use of appropriate antibiotics. This will reduce the use of empirical treatment, morbidity and chronicity
Résumé
OBJETIVO: Determinar o número de unidades formadoras de colônias que melhor correlaciona com a infecção relacionada a cateter em recém-nascidos. MÉTODOS: Este foi um estudo prospectivo de culturas semiquantitativas de pontas de cateteres de recém-nascidos da unidade neonatal da Faculdade de Medicina de Botucatu. Os microrganismos isolados de cateteres e hemoculturas periféricas foram identificados e submetidos ao teste de sensibilidade a drogas. O ponto de corte ótimo foi determinado pela curva receiver operating characteristic (ROC). RESULTADOS: Foram estudados 85 cateteres de 63 recém-nascidos. A espécie Staphylococcus epidermidis foi prevalente (75 por cento) nos cateteres. Dos 11 episódios de infecção diagnosticados, oito (72,7 por cento) foram associados aos estafilococos coagulase-negativa, dos quais seis pertenciam à espécie S. epidermidis. Pela curva ROC, o ponto de corte ótimo para o diagnóstico de infecção relacionada a cateter foi 122 unidades formadoras de colônias. CONCLUSÃO: O ponto de corte 122 unidades formadoras de colônias melhor se correlacionou com o diagnóstico de infecção relacionada a cateter em recém-nascidos.
OBJECTIVE: To determine the number of colony-forming units (CFU) that best correlates with catheter-related infections (CRI) in newborns. METHODS: This was a prospective study of semiquantitative cultures of catheter tips obtained from newborns in the neonatal unit at Faculdade de Medicina de Botucatu, state of São Paulo, Brazil. The microorganisms isolated from catheter and peripheral blood cultures were identified and submitted to a drug susceptibility test. The optimal cutoff point was determined by the receiver operating characteristic (ROC) curve. RESULTS: A total of 85 catheters obtained from 63 newborns were studied. Staphylococcus epidermidis was the predominant species in the catheters (75 percent). Eight of 11 (72.7 percent) CRI episodes were associated with coagulase-negative staphylococci, six of which were of the S. epidermidis type. ROC curve analysis indicated that the optimal cutoff point for the diagnosis of CRI was 122 CFU. CONCLUSION: The cutoff point of 122 CFU correlated best with the diagnosis of CRI in newborns.
Sujets)
Humains , Nouveau-né , Infections sur cathéters/microbiologie , Cathétérisme/instrumentation , Numération de colonies microbiennes , Milieux de culture , Infections sur cathéters/diagnostic , Méthodes épidémiologiques , Infections à staphylocoques/microbiologie , Staphylococcus epidermidis/isolement et purificationRésumé
This prospective study evaluated semiquantitative and qualitative catheter-culture methods for diagnosis of catheter-related infection (CRI) in newborns. Catheter tips from newborns admitted to the Neonatal Unit of the University Hospital of the Botucatu Medical School, UNESP were included in the study. Catheter cultures were performed with both semiquantitative and qualitative techniques. For CRI diagnosis, microorganisms isolated from catheter cultures and from peripheral blood cultures were identified and submitted to agent susceptibility test. The gold standard was the certain CRI diagnosis when same microorganism (specie and profile of susceptibility to agents) was isolated from both catheter tips and peripheral blood culture. A total of 85 catheters from 63 newborns were included in the study. The semiquantitative culture method, despite presenting lower sensitivity (90 percent), showed higher specificity (71 percent) when compared to 100 percent of sensitivity and 60 percent of specificity in the qualitative method. The identification of the microorganisms obtained from the catheter cultures showed a prevalence of coagulase-negative staphylococci(CNS) species. The specie Staphylococcus epidermidis (77.5 percent) was the prevalent in the catheters with positive semiquantitative cultures. Among 11 episodes with CRI diagnosis, 8 (72.7 percent) were associated with CNS species, of which 6 were S. epidermidis. Two episodes of CRI by S. aureus and one by Candida parapsilosis were also detected. The semiquantitative catheter-culture method showed advantages for CRI diagnosis in newborns when compared to the conservative qualitative method.
Este estudo prospectivo avaliou os métodos semiquantitativo e qualitativo de cultura de cateter para o diagnóstico de infecção relacionada a cateter (IRC) em recém-nascidos (RN). Foram incluídas pontas de cateteres provenientes de recém-nascidos internados na Unidade Neonatal do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP. Foram utilizadas as técnicas semiquantitativa e qualitativa de cultura de cateter. Para o diagnóstico de IRC, os microrganismos isolados das culturas de cateteres e de hemoculturas periféricas foram identificados e submetidos ao teste de sensibilidade a antimicrobianos. O padrão ouro correspondeu ao diagnóstico de certeza de IRC, com o isolamento do mesmo microrganismo (espécie e perfil de sensibilidade a antimicrobianos) isolado em hemocultura periférica. Foram estudados 85 cateteres provenientes de 63 RN. A cultura semiquantitativa, embora tenha apresentado menor sensibilidade (90 por cento), apresentou uma maior especificidade (71 por cento) em comparação à sensibilidade de 100 por cento e especificidade de 60 por cento encontradas na cultura qualitativa. Através da identificação dos microrganismos obtidos nas culturas de cateteres, observou-se uma predominância de espécies de Estafilococos coagulase-negativa (ECN). A espécie Staphylococcus epidermidis foi a prevalente (77,5 por cento) nos cateteres com culturas semiquantitativas positivas. Dos 11 episódios de IRC diagnosticados, 8 (72,7 por cento) foram associados a espécies de ECN, dos quais 6 eram da espécie S. epidermidis. Também foram detectados dois casos de IRC por S. aureus e um caso por Candida parapsilosis. O método de cultura semiquantitativo cateter apresentou vantagens para o diagnóstico de IRC em RN quando comparado com o método qualitativo tradicional.