Impact of infections and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae on graft and patient survival in a kidney transplantation program in Mexico.

INTRODUCTION: Immunosuppressive treatments have improved graft and patient survival rates, but can increase the incidence of post-transplant infections. OBJECTIVES: To analyze data from kidney transplant patients and describe the pathogens responsible for the infections they experience. METHODS: Longitudinal, analytical, observational study of 103 patients who underwent kidney transplantation. The follow-up period was 5.07 ± 1.28 years. RESULTS: Overall mortality rate was 10.68% and graft loss rate was 14.56%. Regarding recipient risk of death, the Cox regression model showed a hazard ratio (HR) of 5.66 for positive bacterial cultures and 2.22 for positive extended-spectrum beta-lactamase (ESBL)-producing strains; as for graft loss, HR was 4.59 in those with positive bacterial cultures and 4.25 in those who were positive for ESBL-producing strains. CONCLUSIONS: Significant death risk was found in kidney transplant recipients with positive bacterial cultures and an increased risk of graft loss in those with positive bacterial cultures and in those who were positive for ESBL-producing Enterobacteriaceae isolates. The rate of ESBL-producing Enterobacteriaceae is high, and stricter strategies are therefore necessary to control the use of antibiotics.

INTRODUCCIÓN: Los tratamientos inmunosupresores han mejorado las tasas de supervivencia del injerto y del paciente, pero pueden incrementar las infecciones postrasplante. OBJETIVOS: Analizar los datos de pacientes con trasplante renal y describir las bacterias responsables de las infecciones que presentan. MÉTODOS: Estudio observacional, longitudinal y analítico de 103 pacientes sometidos a trasplante renal. El periodo de seguimiento fue de 5.07 ± 1.28 años. RESULTADOS: La tasa de mortalidad fue de 10.68 % y la de pérdida del injerto de 14.56 %. Respecto al riesgo de muerte del receptor, el modelo de regresión de Cox mostró un cociente de riesgo (HR, hazard ratio) de 5.66 en los pacientes con cultivo bacteriano positivo y de 2.22 en aquellos con cepas productoras de betalactamasas de espectro extendido (BLEE); en cuanto a la pérdida del injerto, el HR fue de 4.59 en quienes tuvieron cultivo bacteriano positivo y de 4.25 en aquellos con cepas productoras de BLEE. CONCLUSIONES: Se encontró riesgo significativo de muerte en receptores de trasplante renal con cultivo bacteriano positivo y mayor riesgo de pérdida del injerto en aquellos con cultivo bacteriano positivo y aislamiento de cepas productoras de BLEE. La tasa de enterobacterias productoras de BLEE es alta, por ello son necesarias estrategias más estrictas para controlar del uso de antibióticos.

Impacto de infecciones y enterobacterias productoras de betalactamasa de espectro extendido en la supervivencia del injerto y del paciente en un programa de trasplante renal en México / Impact of infections and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae on graft and patient survival in a kidney transplantation program in Mexico

Resumen Introducción: Los tratamientos inmunosupresores han mejorado las tasas de supervivencia del injerto y del paciente, pero pueden incrementar las infecciones postrasplante. Objetivos: Analizar los datos de pacientes con trasplante renal y describir las bacterias responsables de las infecciones que presentan. Métodos: Estudio observacional, longitudinal y analítico de 103 pacientes sometidos a trasplante renal. El periodo de seguimiento fue de 5.07 ± 1.28 años. Resultados: La tasa de mortalidad fue de 10.68 % y la de pérdida del injerto de 14.56 %. Respecto al riesgo de muerte del receptor, el modelo de regresión de Cox mostró un cociente de riesgo (HR, hazard ratio) de 5.66 en los pacientes con cultivo bacteriano positivo y de 2.22 en aquellos con cepas productoras de betalactamasas de espectro extendido (BLEE); en cuanto a la pérdida del injerto, el HR fue de 4.59 en quienes tuvieron cultivo bacteriano positivo y de 4.25 en aquellos con cepas productoras de BLEE. Conclusiones: Se encontró riesgo significativo de muerte en receptores de trasplante renal con cultivo bacteriano positivo y mayor riesgo de pérdida del injerto en aquellos con cultivo bacteriano positivo y aislamiento de cepas productoras de BLEE. La tasa de enterobacterias productoras de BLEE es alta, por ello son necesarias estrategias más estrictas para controlar del uso de antibióticos.

Abstract Introduction: Immunosuppressive treatments have improved graft and patient survival rates, but can increase the incidence of post-transplant infections. Objectives: To analyze data from kidney transplant patients and describe the pathogens responsible for the infections they experience. Methods: Longitudinal, analytical, observational study of 103 patients who underwent kidney transplantation. The follow-up period was 5.07 ± 1.28 years. Results: Overall mortality rate was 10.68% and graft loss rate was 14.56%. Regarding recipient risk of death, the Cox regression model showed a hazard ratio (HR) of 5.66 for positive bacterial cultures and 2.22 for positive extended-spectrum beta-lactamase (ESBL)-producing strains; as for graft loss, HR was 4.59 in those with positive bacterial cultures and 4.25 in those who were positive for ESBL-producing strains Conclusions: Significant death risk was found in kidney transplant recipients with positive bacterial cultures and an increased risk of graft loss in those with positive bacterial cultures and in those who were positive for ESBL-producing Enterobacteriaceae isolates. The rate of ESBL-producing Enterobacteriaceae is high, and stricter strategies are therefore necessary to control the use of antibiotics.

Does chlorhexidine mouthwash reduce the rate of oral colonization bygram-negative bacteria in patients with chemotherapy? Aplacebo-controlled trial.

The presence of gram-negative bacteria in the oral cavity is an undesirable occurrence in patients undergoing chemotherapy. Our aim was to investigate the antibacterial effect of 0.12% chlorhexidine mouthwash in chemotherapypatients with a randomized, double-blind, placebo-controlled trial. There were no significant differences between oral colonization rates; there may be local factors that interfere with chlorhexidine activity.

Isopropyl alcohol is as efficient as chlorhexidine to prevent contamination of blood cultures.

BACKGROUND: False-positive blood cultures can lead to unnecessary risks and misuse of antibiotics; to reduce rates of false-positives, it would be useful to determine whether use of an antiseptic with a prolonged effect is required. METHODS: Clinical study of efficacy (blinded and randomized) to compare the rate of blood culture contamination when skin antisepsis was performed with 70% isopropyl alcohol or 2% chlorhexidine gluconate in 70% isopropyl alcohol in 2 hospitals. Patients aged 16 years or older with suspected bloodstream infection who were allocated in the emergency room, internal medicine ward, or intensive care unit were included. RESULTS: Five of 563 (0.9%) blood cultures from the isopropyl arm and 10 of 539 (1.9%) from the chlorhexidine arm were contaminated. No significant differences were observed among the rate of contamination (χ2=1.27; P = .3) or the relative risk of contamination (relative risk = 2.09; 95% confidence interval, 0.72-6.07; P = .2). CONCLUSIONS: The rates of blood contamination were not different when isopropyl alcohol and chlorhexidine were compared. Isopropyl alcohol could be used for skin antisepsis before blood collection.

Decontamination of stethoscope membranes with chlorhexidine: Should it be recommended?

OBJECTIVE: To determine differences in the recontamination of stethoscope membranes after cleaning with chlorhexidine, triclosan, or alcohol. METHODS: Experimental, controlled, blinded trial to determine differences in the bacterial load on stethoscope membranes. Membranes were cultured by direct imprint after disinfection with 70% isopropyl alcohol, 1% triclosan, or 1% chlorhexidine and normal use for 4 hours. As a baseline and an immediate effect control, bacterial load of membranes without disinfection and after 1 minute of disinfection with isopropyl alcohol was determined as well. RESULTS: Three hundred seventy cultures of in-use stethoscopes were taken, 74 from each arm. In the baseline arm the median growth was 10 CFU (interquartile range [IQR], 32-42 CFU); meanwhile, in the isopropyl alcohol immediate-effect arm it was 0 CFU (IQR, 0-0 CFU). In the arms cultured after 4 hours, a median growth of 8 CFU (IQR, 1-28 CFU) in the isopropyl alcohol arm, 4 CFU (IQR, 0-17 CFU) in the triclosan arm, and 0 CFU (IQR, 0-1 CFU) in the chlorhexidine arm were seen. No significant differences were observed between the bacterial load of the chlorhexidine arm (after 4 hours of use) and that of the isopropyl alcohol arm (after 1 minute without use) (Z= 2.41; P > .05). CONCLUSIONS: Chlorhexidine can inhibit recontamination of stethoscope membranes and its use could help avoid cross-infection.

Chlorhexidine avoids skin bacteria recolonization more than triclosan.

BACKGROUND: We do not know whether differences exist between the residual effect of 2% chlorhexidine in 70% isopropyl alcohol when compared with 1% triclosan in 70% isopropyl alcohol. METHODS: Using an analytic, longitudinal, controlled, and comparative experimental trial, with blinded measurements, we recruited healthy, adult volunteers from the University of Guanajuato who completed a stabilization phase of skin microbiota and had no history of skin allergies. Four 25-cm2 areas of the inner surface of the forearms were designated for study: unscrubbed control for establishing baseline bacterial counts, scrubbed control with tridistilled water, scrubbed with chlorhexidine, and scrubbed with triclosan. Quantitative cultures were taken of all the areas at 0, 3, and 24 hours, using agar plates with neutralizing agents. RESULTS: A total of 135 healthy volunteers were tested. At 24 hours, the unscrubbed control counts were 288 CFU/cm2, whereas the scrubbed control counts were 96 CFU/cm2; 24 CFU/cm2 for chlorhexidine and 96 CFU/cm2 for triclosan (Kruskal-Wallis χ2H = 64.27; P <.001). CONCLUSIONS: Chlorhexidine is the best antiseptic option when a prolonged antiseptic effect is needed; for instance, when implanting medical devices or performing surgical procedures.

Antimicrobial activity of copper against organisms in aqueous solution: a case for copper-based water pipelines in hospitals?

BACKGROUND: An association exists between water of poor quality and health care-associated infections. Copper shows microbiocidal action on dry surfaces; it is necessary to evaluate its antimicrobial effect against organisms in aqueous solution. OBJECTIVE: The objective was to determine the in vitro antimicrobial activity of copper against common nosocomial pathogens in aqueous solution. METHODS: Copper and polyvinyl chloride containers were used. Glass was used as control material. Fourteen organisms isolated from hospital-acquired infections, and 3 control strains were tested. Inocula were prepared by direct suspension of colonies in saline solution and water in each container tested. Bacterial counts in colony-forming units (CFU)/mL were determined at the beginning of the experiment; at 30 minutes; and at 1, 2, 24, and 48 hours. RESULTS: Organisms in glass and polyvinyl chloride remained viable until the end of the experiment. Organisms in copper showed a reduction from more than 100,000 CFU/mL to 0 CFU/mL within the first 2 hours of contact (F > 4.29, P < .001). CONCLUSION: Copper containers show microbiocidal action on organisms in aqueous solution. Copper may contribute to the quality of water for human use, particularly in hospitals.

Chlorhexidine is a better antiseptic than povidone iodine and sodium hypochlorite because of its substantive effect.

BACKGROUND: The present study compared both the antiseptic efficacy of sodium hypochlorite against that of chlorhexidine gluconate in isopropyl alcohol and the substantive effect of chlorhexidine, povidone iodine, and sodium hypochlorite. METHODS: This was a 2-step study that included volunteers. In step 1, 4 skin areas were tested for bacteria in colony-forming units (CFU): 2 were controls to determine baseline bacteria or the effect of scrubbing, and 2 were treated with 10% hypochlorite or 2% chlorhexidine in isopropyl alcohol. Every subject was tested 4 times. The second step tested the substantive effect of 10% povidone-iodine and the aforementioned antiseptics. RESULTS: For the first step, 30 volunteers were studied, resulting in 120 determinations for each control and antiseptic. No differences between chlorhexidine gluconate (median 115 CFU/cm(2)) and sodium hypochlorite (median 115 CFU/cm(2)) were found. Both antiseptics were significantly different from rubbing control (317 CFU/cm(2)) and basal control (606 CFU/cm(2)). Only chlorhexidine showed a substantive effect. CONCLUSION: We consider that chlorhexidine gluconate in isopropyl alcohol, sodium hypochlorite, and povidone-iodine is equally effective for procedures that do not require a long action. However, chlorhexidine is desirable for procedures such as catheter insertion, skin preparation for surgery, or handwashing prior to surgery.

Asymptomatic bacteriuria in preadolescent girls.

BACKGROUND: The detection of asymptomatic bacteriuria in preadolescent girls may be important due to its effects on subsequent pregnancies. OBJECTIVE: To describe the prevalence of asymptomatic bacteriuria in preadolescent girls and the value of the nitrite test for screening. MATERIAL AND METHODS: Cross-sectional study in girls aged 9 to 13 years. Bacteriuria was defined as the growth of > 100,000 CFU/mL in 2 consecutive urine specimens. RESULTS: Three hundred and twenty seven girls were included. Asymptomatic bacteriuria was found in 7 girls, so the prevalence was 2.1% (95% CI, 1 to 4.4%). Escherichia coli was the isolated agent in all the cases. Focused interrogatory found history of urinary symptoms in 6 girls. The utility values of the nitrite test were: sensitivity, 1; specificity, 0.9; positive likelihood ratio, 10; and negative predictive value, 1. CONCLUSIONS: The prevalence of asymptomatic bacteriuria in preadolescent girls in this Mexican study is similar to the one reported internationally; it is reasonable to consider its early detection to avoid its effects on future pregnancies. Nitrite test seems to be good for screening.

[Influenza A H1N1 (2009): considerations at the time of declaring the end of the contingency in Mexico]. / La influenza A H1N1 (2009): el recuento al declararse el término de la contingencia en México.

We review important aspects of the pandemic influenza A (H1N1) at the time of declaring the end of the contingency in Mexico. The pre-established surveillance system had to be modified during the course of the epidemic. From the first epidemic weeks, viral monitoring recorded the displacement of other pathogens by the pandemic virus. Patients at high risk for complications were identified together with the need for early treatment with antiviral drugs, thus avoiding the saturation of intensive care beds. The difficulties of surging services for seriously ill patients are described. Preventive measures such as the use of masks and hand hygiene are reviewed, as well as the vaccination drive and the difficulties for its application in health personnel. The review concludes with the need to learn the teachings of the pandemic, describing the necessary elements to prepare against the next one.

[HIV in Mexican blood donors and estimated transfusional risk]. / VIH en donadores mexicanos de sangre y el riesgo calculado de la transfusión.

OBJECTIVE: To determine the HIV seroprevalence in Mexican blood donors and the residual risk of transfusion. MATERIAL AND METHODS: The seroprevalence was determined in a sample of first-time blood donors at one hospital center in Mexico City, from 2003 to 2007. To estimate the seroprevalence reported in Mexican blood donors, we reviewed recent papers. To determine the positive likelihood ratio (LR+) of the EIA test the specificity was calculated against the western-blot result. To infer the residual risk, the incident infections were assumed to be 1.8 times more frequent for first-time donors. RESULTS: We analyzed 29,318 donors; 66 were reactive to HIV by EIA (225/100,000; 95% Confidence Interval: 171 to 279/100,000), but western-blot confirmed only 5 (prevalence = 17/100,000 donors; 95% CI: 2 to 32/100,000). The maximal residual risk was inferred to be 6.2 per million, or about 6.8 per year. The LR+ of the EIA test was calculated to be 476. The Bayesian analysis estimated that the disease is present in only 7.5% donors with a reactive EIA. Published reports in medical literature do not inform confirmatory tests for Mexican donors. DISCUSSION: The residual risk for HIV had been calculated to be about 100 per million of blood donors. Although we inferred that the risk had been overestimated by not performing confirmatory tests, the results are a call for action as the risk is still several times higher than the one reported in industrialized countries.

[Microbiology of urinary tract infections in ambulatory patients. Therapeutic options in times of high antibiotic resistance]. / Microbiología de las infecciones urinarias en pacientes ambulatorios. Opciones terapéuticas en tiempos de alta resistencia a los antibióticos.

OBJECTIVE: To determine the antibiotic resistance of urinary pathogens in ambulatory patients from Mexico City, in order to infer therapeutic options in environments of high resistance. METHODS: Cross sectional survey performed between July 2006, and January 2007, in patients > or =3 year-old from a private institution. Cultured organisms were identified with a commercial biochemical system. For common antibiotics, susceptibility was performed by broth microdilution with a commercial system; for fosfomycin tromethamine, the disk diffusion test was performed. RESULTS: From 1685 urine specimens, 257 (15.3%) yielded a positive culture; 215 (83.7%) from women and 42 (16.3%) from men. Global resistance was the following: ampicillin, 68.4%; co-amoxiclav, 19.5%; ciprofloxacin, 36.3%; cephalothin, 64.7%; ceftriaxone, 12.2%; cefuroxime, 18.7%; nitrofurantoin, 19%; trimethoprim-sulphamethoxazol, 53.4%; gentamicin, 18.9%; and fosfomycin tromethamine, 0.8%. Escherichia coli was the main pathogen, with 203 (79%) isolations; its specific resistance was similar to the global one, and its production of extended-spectrum beta-lactamases (ESBLs) was 9.4%. CONCLUSIONS: The high resistance rate found is alarming; we have few options for the initial treatment of urinary tract infections in ambulatory patients. To control the problem, health authorities must regulate the indiscriminate use of antibiotics.

[Catalase test (Uriscreen) in the detection of bacteriuria-candiduria in hospitalized adults with Foley catheter]. / Prueba de catalasa (Uriscreen) para la detección de bacteriuria-candiduria en adultos hospitalizados con sonda de Foley.

BACKGROUND: Most urinary pathogens have the catalase enzyme, which has been used recently for detection of bacteriuria-candiduria, by an economic reaction in a tube containing 10% hydrogen peroxide and a catalyzer (Uriscreen). It has not been studied in patients with indwelling urinary catheter. OBJECTIVE: To determine the accuracy of the catalase test (CT) in hospitalized patients with indwelling urinary catheters and to compare it against other rapid tests (nitrites and pyuria detection). METHODS: The gold standard was the culture of urine, with 10(3) colony-forming units/mL as the threshold for significant growth. The nitrite test was determined by dipstick. The pyuria was determined by dipstick and microscopic examination. RESULTS: Of 108 cultures from 57 patients, 62 were positives (57.4%). The values of accuracy of the CT were (%): sensitivity 88.5, specificity 42.6, predictive positive value 66.7, and predictive negative value 74.1. Compared against nitrites detection the CT showed higher sensitivity and specificity. Against pyuria detection, it showed higher sensitivity, but lower specificity. CONCLUSIONS: Our study complements medical literature as it is the first focused in patients with indwelling catheter. The clinical use of the CT is limited and not superior to pyuria detection in this setting. However, because of its high sensitivity and low cost, it could be recommended for ruling out bacteriuria-candiduria in selected patients. A negative CT may prevent the need for expensive cultures.