Resistencia antibiótica de Escherichia coli y Staphylococcus saprophyticus en la infección urinaria de un hospital público / Antibiotic resistance of Escherichia coli and Staphylococcus saprophyticus in urinary tract infection in a public hospital

La resistencia de antibióticos puede llegar a causar una amplia morbilidad y complicaciones. Objetivo: Determinar el perfil de resistencia antimicrobiana de Escherichia Coli y de Staphylococcus Saprophyticus, en pacientes con infección urinaria hospitalizados en el servicio de Medicina Interna del Hospital Municipal Los Olivos. Métodos: Estudio descriptivo, retrospectivo de corte transversal. Se realizó en el servicio de Medicina Interna del Hospital Municipal los Olivos (HMLO). Participantes: historia clínica de pacientes hospitalizados con infección urinaria en el servicio de Medicina Interna. Intervenciones: Según los criterios de inclusión y exclusión se obtuvieron, 96 historias clínicas (HC) del año 2013. Se utilizó un instrumento de recolección validado. Se realizó el análisis descriptivo con software estadístico STATA versión 25. Resultados: De las 96 HC, la edad promedio fue 55,04 años, los agentes microbianos más frecuentes fueron: la Escherichia coli con 85,3%, Staphylococcus saprophyticus 4.2% y Klebsiella pneumoniae 3,1%. La prevalencia de productores de betalactamasa espectro extendido (BLEE) fue 10,4%. Los antibióticos más resistentes fueron: trimetoprim/sulfametoxazol 89,6%, ampicilina 86%, piperacilina 84,6%, tetraciclina 79,2% y ciprofloxacino 70,8%. Los antibióticos más sensibles fueron: amikacina 100%, imipenem 100%, ertapenem 98%, meropenem 96% y piperacilina/tazobactam 96%. Conclusión: El uropatógeno más frecuente en pacientes con ITU hospitalizados fue la E. coli. Los antibióticos que presentaron resistencia a la E. coli fueron: trimetoprim/sulfametoxazol, ampicilina, piperacilina, tetraciclina y ciprofloxacino, y para el S. Saprophyticus fueron: amoxicilina/ ácido clavulánico, trimetoprim/sulfametoxazol, ceftriaxona y ciprofloxacino(AU)

Resistance to antibiotics may actually cause extensive morbidity and complications. Objective: To determine the antimicrobial resistance profile of Escherichia coli and Staphylococcus saprophyticus, in patients with urinary infection hospitalized in the Internal Medicine service of the Los Olivos Municipal Hospital. Methods: Descriptive, retrospective cross-sectional study. It was carried out in the Internal Medicine service of the Los Olivos Municipal Hospital (HMLO). Participants: clinical history of hospitalized patients with urinary infection in the Internal Medicine service. Interventions: According to the inclusion and exclusion criteria, 96 clinical records (HC) from 2013 were obtained. A validated collection instrument was used. Descriptive analysis was performed with STATA version 25 statistical software. Results: Of the 96 CHs, the average age was 55.04 years, the most frequent microbial agents were: Escherichia Coli with 85.3%, Staphylococcus saprophyticus 4.2% and Klebsiella pneumoniae 3.1%. The prevalence of extended spectrum beta-lactamase producers (ESBL) was 10.4%. The most resistant antibiotics were trimethoprim / sulfamethoxazole 89.6 %, ampicillin 86 %, piperacillin 84.6 %, tetracycline 79.2 % and ciprofloxacin 70.8 %. The most sensitive antibiotics were: amikacin 100%, imipenem 100%, ertapenem 98%, meropenem 96% and piperacillin / tazobactam 96%. Conclusion: The most common uropathogen in hospitalized UTI patients was E. coli. The antibiotics that showed resistance to E. coli were: trimethoprim/sulfamethoxazole, ampicillin, piperacillin, tetracycline, and ciprofloxacin, and for S. saprophyticus they were: amoxicillin/clavulanic acid, trimethoprim / sulfamethoxazole, ceftriaxone and ciprofloxacin(AU)

Infecciones urinarias por Streptococcus agalactiae y Staphylococcus saprophyticus y embarazo / Urinary tract infections due to Streptococcus agalactiae and Staphylococcus saprophyticus and pregnancy / Infecções urinárias por Streptococcus agalactiae y Staphylococcus saprophyticus e gravidez

Distintos autores difieren en la mayor o menor prevalencia de las infecciones urinarias (IU) por Streptococcus agalactiae y Staphylococcus saprophyticus en mujeres embarazadas (ME) y no embarazadas (NE). Se realizó un estudio retrospectivo, comparativo, de cohortes con el objetivo de evaluar la frecuencia de IU por S. agalactiae y S. saprophyticus en ME asintomáticas pertenecientes a centros de atención primaria de la salud del Municipio de La Plata (CAPS) entre 2008 y 2016 y se la comparó con la de NE sintomáticas en edad fértil, no internadas, que asistieron al Hospital "San Roque" (HSR) entre 2014 y 2017. Se procesaron 2.378 orinas de ME que concurrieron a las CAPS. De ese total, 201 fueron positivas (8,5%), el 10,4% de las mismas (n: 21) correspondieron a S. agalactiae y el 10,0% a S. saprophyticus (n: 20). En el 54% se aisló Escherichia coli. El total de urocultivos en la población de NE fue de 2.281 y 526 fueron positivos (23,1%): 7 correspondieron a S. agalactiae (1,3%), 18 a S. saprophyticus (3,4%) y el 78% a E. coli. En conclusión, la frecuencia de aislamiento de S. agalactiae y S. saprophyticus fue significativamente mayor en la población de ME pertenecientes a las CAPS respecto de las NE estudiadas en el HSR.

Several authors differ in the greater or lesser prevalence of urinary tract infections (UTI) due to Streptococcus agalactiae and Staphylococcus saprophyticus in pregnant women (PW) and non-pregnant women (NPW). A retrospective, comparative, cohort study was carried out with the objective of evaluating the frequency of UTI by S. agalactiae and S. saprophyticus in asymptomatic PW from primary care centers of the Municipality of La Plata (PCC) between 2008 and 2016 and comparing it with symptomatic NPW in a fertile age, not hospitalized women, who attended the "San Roque" Hospital (HSR) between 2014 and 2017. A total of 2,378 urine samples from PW assisted at the PCC were processed. Two hundred and one were positive (8.5%); 10.4% of them (n: 21) corresponded to S. agalactiae and 10.0% to S. saprophyticus (n: 20). Escherichia coli was isolated in 54%. The total of urine cultures in the population of NPW of the HSR was 2,281 and 526 were positive (23.1%): 7 corresponded to S. agalactiae (1.3%), 18 to S.saprophyticus (3.4%) and 78% to E. coli. In conclusion, the frequency of isolation of S. agalactiae and S. saprophyticus was significantly higher in the population of PW belonging to the PCC than in the NPW studied in the HSR.

Diferentes autores diferem na maior ou menor prevalência das infecções do trato urinário (ITU) devido a Streptococcus agalactiae e Staphylococcus saprophyticus em mulheres grávidas (MG) e mulheres não grávidas (NG). Realizou-se um estudo retrospectivo e comparativo de coortes com o objetivo de avaliar a frequência de ITU por S.agalactiae e S.saprophyticus em MGs assintomáticas pertencentes a salas de atendimento primário do município de La Plata (CAPS) entre 2008 e 2016 e compará-lo com NG sintomáticas em idade fértil, não hospitalizadas, que frequentaram o Hospital "San Roque" (HSR) entre 2014 e 2017. Foram processadas 2.378 amostras de urina de MG atendidas nas CAPS. Desse total, 201 foram positivos (8,5%), 10,4% das mesmas (n: 21) corresponderam a S. agalactiae e 10,0% a S. saprophyticus (n: 20). Escherichia coli foi isolada em 54%. As culturas de urina total na população de NG foram de 2.281 e 526 foram positivas (23.1%): 7 correspondem a S.agalactiae (1.3%), 18 a S.saprophyticus (3.4%) e 78% para E. coli. Em conclusão, a frequência de isolamento de S. agalactiae e S. saprophyticus foi significativamente maior na população de MG pertencente às CAPS do que as NG estudadas no HSR.

Correlation of phenotypic tests with the presence of the blaZ gene for detection of beta-lactamase

Abstract Staphylococcus aureus and Staphylococcus saprophyticus are the most common and most important staphylococcal species associated with urinary tract infections. The objective of the present study was to compare and to evaluate the accuracy of four phenotypic methods for the detection of beta-lactamase production in Staphylococcus spp. Seventy-three strains produced a halo with a diameter ≤28 mm (penicillin resistant) and all of them were positive for the blaZ gene. Among the 28 susceptible strain (halo ≥29 mm), 23 carried the blaZ gene and five did not. The zone edge test was the most sensitive (90.3%), followed by MIC determination (85.5%), but the specificity of the former was low (40.0%). The nitrocefin test was the least sensitive (28.9%). However, the nitrocefin test together with the disk diffusion method showed the highest specificity (100%). The present results demonstrated that the zone edge test was the most sensitive phenotypic test for detection of beta-lactamase, although it is still not an ideal test to detect this type of resistance since its specificity was low. However, the inhibition halo diameter of the penicillin disk can be used together with the zone edge test since the same disk is employed in the two tests. Combined analysis of the two tests shows a sensitivity of 90.3% and specificity of 100%, proving better sensitivity, especially for S. saprophyticus. This is a low-cost test of easy application and interpretation that can be used in small and medium-sized laboratories where susceptibility testing is usually performed by the disk diffusion method.

Staphylococcus saprophyticus Bacteremia originating from Urinary Tract Infections: A Case Report and Literature Review

Staphylococcus saprophyticus is a common pathogen of acute urinary tract infection (UTI) in young females. However, S. saprophyticus bacteremia originating from UTI is very rare and has not been reported in Korea. We report a case of S. saprophyticus bacteremia from UTI in a 60-year-old female with a urinary stone treated successfully with intravenous ciprofloxacin, and review the cases of S. saprophyticus bacteremia reported in the literature. Thus, the microorganism may cause invasive infection and should be considered when S. saprophyticus is isolated from blood cultures in patients with UTI.

Infecção urinária comunitária: etiologia segundo idade e sexo / Community-acquired urinary tract infection: age and gender-dependent etiology

INTRODUÇÃO: A escolha do antimicrobiano para tratamento inicial de infecção de trato urinário (ITU) costuma ser empírica e deve considerar a prevalência dos uropatógenos nas diversas faixas etárias e sexo. OBJETIVO: Avaliar a prevalência de uropatógenos em ITU comunitária e sua relação com idade e sexo. MÉTODOS: Estudo transversal conduzido em pronto socorro (PS) de hospital geral, de janeiro a dezembro, 2010, em pacientes menores de 15 anos com suspeita clínica de ITU, que colheram urocultura quantitativa. Definida ITU como urocultura com crescimento de agente único > 100.000 unidades formadoras de colônia (ufc)/mL na coleta por jato médio ou > 50.000 ufc/mL na coleta por sondagem vesical. RESULTADOS: Ocorreram 63.464 atendimentos no PS. Foram obtidas 2.577 uroculturas; destas, 291 foram positivas para ITU (prevalência = 11,3% das suspeitas clínicas e 0,46% dos atendimentos); 212 casos (72,8%) em meninas, mediana de idade = 2,6 anos. O uropatógeno predominante foi E.coli (76,6%), seguido por Proteus mirabilis (10,3%) e Staphylococcus saprophyticus (4,1%). Em lactentes < 3 meses, a prevalência de E.coli foi significativamente menor (50% x 78,4%; OR = 0,276; p = 0,006). Maior prevalência de Staphylococcus saprophyticus ocorreu em pacientes > 10 anos (24,4% x 0,4%; OR = 79,265; p < 0,0001). Proteus mirabilis foi significativamente mais prevalente em meninos (24,0% x 5,2%; OR = 5,786; p < 0,001). CONCLUSÕES: E. coli foi o uropatógeno mais prevalente das ITU comunitárias. Entretanto, na escolha do antimicrobiano empírico inicial, deve-se levar em consideração a prevalência significativa de outros agentes diferentes de E. coli em lactentes < 3 meses, a alta prevalência de Staphylococcus saprophyticus em pacientes > 10 anos e de Proteus mirabilis em meninos.

INTRODUCTION: Choosing the antimicrobial agent for initial therapy of urinary tract infection (UTI) is usually empirical and should consider the prevalence of uropathogens in different age groups and gender. OBJECTIVE: To establish prevalence rates of uropathogens in community-acquired UTI in relation to age and gender. METHODS: Crosssectional study conducted in the emergency department (ED) of a general hospital, from January to December, 2010, in patients younger than 15 years old who had clinical suspicion of UTI and collected quantitative urine culture. UTI was defined as urine culture with growth of a single agent > 100.000 colony forming units (cfu)/mL in a midstream collection or > 50.000 cfu/mL in urethral catheterization. RESULTS: There were 63.464 visits to ED. 2577 urine cultures were obtained, of whom 291 were positive for UTI (prevalence = 11.3% of clinical suspicion and 0.46% of visits), 212 cases (72.8%) in females, median age = 2.6 years. The predominant uropathogen was E. coli (76.6%), followed by Proteus mirabilis (10.3%) and Staphylococcus saprophyticus (4.1%). Among infants < 3 months, prevalence rates of E. coli were significantly lower (50% vs 78.4%; OR = 0.276; p = 0.006). Higher prevalences of Staphylococcus saprophyticus occurred among patients > 10 years (24.4% vs 0.4%; OR = 79.265; p < 0.0001). Proteus mirabilis was significantly more prevalent in boys than girls (24.0% vs 5.2%; OR = 5.786; p < 0.001). CONCLUSIONS: E. coli was the most prevalent community-acquired uropathogen. Nevertheless, initial empiric antimicrobial treatment of UTI should consider the significant prevalence of other agents different from E. coli in infants < 3 months, the high prevalence of Staphylococcus saprophyticus in patients > 10 years and Proteus mirabilis in males.

Time-based distribution of Staphylococcus saprophyticus pulsed field gel-electrophoresis clusters in community-acquired urinary tract infections

The epidemiology of urinary tract infections (UTI) by Staphylococcus saprophyticus has not been fully characterised and strain typing methods have not been validated for this agent. To evaluate whether epidemiological relationships exist between clusters of pulsed field gel-electrophoresis (PFGE) genotypes of S. saprophyticus from community-acquired UTI, a cross-sectional surveillance study was conducted in the city of Rio de Janeiro, Brazil. In total, 32 (16%) female patients attending two walk-in clinics were culture-positive for S. saprophyticus. Five PFGE clusters were defined and evaluated against epidemiological data. The PFGE clusters were grouped in time, suggesting the existence of community point sources of S. saprophyticus. From these point sources, S. saprophyticus strains may spread among individuals.

Frequency and Clinical Characteristics of Urinary Tract Infections Caused by Staphylococcus saprophyticus / 대한임상미생물학회지

BACKGROUND: Staphylococcus saprophyticus is the second most common cause of urinary tract infections (UTIs) in young women. As little is known about the incidence of UTIs caused by this organism in Korea, we examined its frequency and clinical characteristics. METHODS: We analyzed the frequency of S. saprophyticus among organisms isolated from urine specimens in Wonju Christian Hospital from July 1996 to June 2008 and reviewed clinical characteristics retrospectively. RESULTS: Of 24,277 strains isolated from urine specimens during the past 12 years, 21 (0.09%) were S. saprophyticus. Outpatients were more common in the S. saprophyticus group than in all patients group (12 of 21, 57% vs 5,098 of 24,277, 21%). The incidence of S. saprophyticus in women was the highest in the group of 15 to 34 years of age. Monthly distributions of isolates were almost constant in all patient groups, while 16 of 21 (76%) cases of the S. saprophyticus group occurred in summer and fall (June to November). CONCLUSION: The fequencies of S. saprophyticus among organisms isolated from urine specimens in all patient groups and women were 0.09% and 0.17%, respectively, and are much lower than those in other countries. However, we need further studies to examine the prevalence of S. saprophyticus UTIs in other regions of this country.

Aspectos epidemiológicos, clínicos y bacteriológicos en infeccion urinaria por Staphylococcus saprophyticus / Epidemiological, clinical and bacteriological findings in urinary infections by Staphylococcus saprophyticus

Las infecciones urinarias ocasionadas por Staphylococcus saprophyticus se describen en un grupo muy particular de pacientes. Frecuentemente, éstas son diagnosticadas en mujeres jóvenes no hospitalizadas, con clínica de cistitis, pielonefritis y en oportunidades relacionadas al embarazo. Se presenta en esta revisión los hallazgos clínicos, epidemiológicos y bacteriológicos de esta infección en 131 pacientes en el Hospital Universitario de Caracas, entre enero de 1998 hasta diciembre de 2004. Se encontraron algunas características poco frecuentes, tales como aislamiento en niños y pacientes hospitalizados de ambos sexos. Se presume que esto podría deberse a las características inherentes a la población estudiada.

Urinary infections caused by Staphylococcus saprophyticus have been described in a very particular group of patients. Frequently, these infections are diagnosed in young women off hospital presenting symptoms of cystitis, pyelonephritis. Occasionally, pregnancy was involved. This revision comprises clinical, epidemiological, and bacteriological findings regarding this infection in 131 patients at the Hospital Universitario de Caracas between January 1998 and December 2004. Some of these finding were less frecuenty. For example, isolates were found in children and hospitalized patients from both sexes. It is presumed that these could be attributed to the inherent characteristics of the population under study.

Staphylococcus saprophyticus como patógeno urinario / Staphylococcus saprophyticus as urinary pathogen

Dentro de los estafilococos coagulasa negativo, Staphylococcus saprophyticus (Ssa) es un importante agente causal de infecciones agudas del tracto urinario (UTI) en mujeres en edad sexual activa y está considerado como el segundo agente más frecuente de UTI en esta población, después de Escherichia coli. El objetivo de este trabajo fue determinar la frecuencia con que se aíslan Ssa de mujeres en edad sexual activa y evaluar la sensibilidad de las cepas aisladas. Desde junio del 2001 a junio del 2003 fueron recolectadas cepas de estafilococos coagulasa negativo aisladas de urocultivos provenientes de mujeres en edad comprendida entre 15 y 50 años que concurrieron al Laboratorio San Roque. La identificación presuntiva se realizó mediante pruebas de sensibilidad al disco de novobiocina (5µg) y la confirmación mediante la producción de ácidos a partir de xilosa, manosa, arabinosa y sacarosa. La sensibilidad fue determinada según normas estandarizadas de la NCCLS. De 610 urocultivos positivos se aislaron 50 cepas de Ssa, obteniéndose una prevalencia de 8,2%. Todas las cepas fueron sensibles a gentamicina, norfloxacina, oxacilina, cefalotina, nitrofurantoina y vancomicina, 98% resultaron sensibles a la penicilina y a trimetoprima­sulfametoxazol. Todas las cepas novobiocina resistentes fueron confirmados como Ssa por las pruebas de azucares. Los resultados de frecuencia y sensibilidad del Ssa, coinciden con lo reportado en numerosos trabajos. La prueba del disco de novobiocina es de mucha utilidad para la identificación de los Ssa debido a que estafilococos novobiocina resistentes distintos de Ssa se encuentran con muy poca frecuencia en muestras clínicas humanas.

Staphylococcus saprophyticus(Ssa), a coagulase negative staphylococcus, causes urinary tract infection and is predominant in sexually active young women. Ssa is the second most frequent pathogen in this population after Escherichia coli. The objective of this study was to determine the frequency of Ssa isolates in sexually active women and to evaluate the sensibility to antimicrobial agents. From June 2001 to June 2003, coagulase negative Staphylococcus strains were isolated from urine culture in women with ages ranging from 15 to 50 years. The presumptive identification was determined by a disc susceptibility to novobiocin (5 mcg). The confirmation was performed by xylose, mannose, arabinose and saccharose fermentation. The sensibility to antimicrobial agents was determined by standardised guidelines of NCCLS. From 610 urine cultures, 50 Ssa strains were isolated and the prevalence was 8.2%. All strains were susceptible to gentamicin, norfloxacin, oxacillin, cephalothin, nitrofurantoin and vancomycin. Ninety eight percent was susceptible to penicillin and trimethoprim­sulphamethoxazole. The results of frequency and sensibility were similar to those reported previously. Novobiocin disc test is very useful to identify Ssa because novobiocin resistant staphylococci different from Ssa are rarely found in human clinic samples.