Is Clostridioides difficile toxins detection necessary when the glutamate dehydrogenase enzyme is detected?

INTRODUCTION: Clostridioides difficile causes diarrhea and pseudomembranous colitis. Its diagnosis is made with glutamate dehydrogenase (GDH) or toxins A and B detection and is confirmed with nucleic acid amplification tests. OBJECTIVE: To define if GDH determination is redundant to that of toxins. METHODS: Retrospective, observational study in diarrheal stools of patients with suspected Clostridioides difficile infection. Toxins and GDH were determined by immunochromatography. Bayesian simulation was performed with likelihood ratios; a p-value < 0.05 was regarded as significant. RESULTS: 329 GDH and toxin A and B results were analyzed. Clostridioides difficile infection prevalence was 18.2 %. Sensitivity and specificity of the GDH test were 0.90 and 0.89, respectively. Positive likelihood ratio was 8.9, and negative was 0.11. CONCLUSIONS: A negative GDH result considerably reduces the probability of infection but does not rule it out. Clostridioides difficile toxins detection may be necessary in institutions where nucleic acid amplification is not affordable or accessible.

INTRODUCCIÓN: Clostridioides difficile causa diarrea y colitis pseudomembranosa. Su diagnóstico se realiza con la detección de glutamato-deshidrogenasa (GDH) o las toxinas A y B y se confirma con pruebas de amplificación de ácidos nucleicos. OBJETIVO: Definir si la determinación de GDH es redundante a la de las toxinas. MÉTODOS: Estudio observacional retrospectivo de muestras fecales de pacientes con sospecha de infección por Clostridioides difficile. Las toxinas y GDH se determinaron mediante inmunocromatografía. Se realizó una simulación bayesiana con los cocientes de probabilidad; se consideró significativo un valor de p < 0.05. RESULTADOS: Se analizaron 329 resultados de GDH y toxinas A y B. Se encontró una prevalencia de infección de Clostridioides difficile de 18.2 %. La sensibilidad y especificidad de la prueba de GDH fue de 0.90 y 0.89, respectivamente. El cociente de probabilidad positivo fue de 8.9 y el negativo, de 0.11. CONCLUSIONES: Un resultado negativo de GDH disminuye considerablemente la probabilidad de infección, pero no la descarta. La detección de toxinas de Clostridioides difficile puede ser necesaria en instituciones donde la amplificación de ácidos nucleicos no es económica o accesible.

¿La detección de toxinas de Clostridioides difficile es necesaria cuando se detecta la enzima glutamato deshidrogenasa? / Is Clostridioides difficile toxins detection necessary when the glutamate dehydrogenase enzyme is detected?

Resumen Introducción: Clostridioides difficile causa diarrea y colitis pseudomembranosa. Su diagnóstico se realiza con la detección de glutamato-deshidrogenasa (GDH) o las toxinas A y B y se confirma con pruebas de amplificación de ácidos nucleicos. Objetivo: Definir si la determinación de GDH es redundante a la de las toxinas. Métodos: Estudio observacional retrospectivo de muestras fecales de pacientes con sospecha de infección por Clostridioides difficile. Las toxinas y GDH se determinaron mediante inmunocromatografía. Se realizó una simulación bayesiana con los cocientes de probabilidad; se consideró significativo un valor de p < 0.05. Resultados: Se analizaron 329 resultados de GDH y toxinas A y B. Se encontró una prevalencia de infección de Clostridioides difficile de 18.2 %. La sensibilidad y especificidad de la prueba de GDH fue de 0.90 y 0.89, respectivamente. El cociente de probabilidad positivo fue de 8.9 y el negativo, de 0.11. Conclusiones: Un resultado negativo de GDH disminuye considerablemente la probabilidad de infección, pero no la descarta. La detección de toxinas de Clostridioides difficile puede ser necesaria en instituciones donde la amplificación de ácidos nucleicos no es económica o accesible.

Abstract Introduction: Clostridioides difficile causes diarrhea and pseudomembranous colitis. Its diagnosis is made with glutamate dehydrogenase (GDH) or toxins A and B detection and is confirmed with nucleic acid amplification tests. Objective: To define if GDH determination is redundant to that of toxins. Methods: Retrospective, observational study in diarrheal stools of patients with suspected Clostridioides difficile infection. Toxins and GDH were determined by immunochromatography. Bayesian simulation was performed with likelihood ratios; a p-value < 0.05 was regarded as significant. Results: 329 GDH and toxin A and B results were analyzed. Clostridioides difficile infection prevalence was 18.2 %. Sensitivity and specificity of the GDH test were 0.90 and 0.89, respectively. Positive likelihood ratio was 8.9, and negative was 0.11. Conclusions: A negative GDH result considerably reduces the probability of infection but does not rule it out. Clostridioides difficile toxins detection may be necessary in institutions where nucleic acid amplification is not affordable or accessible.

Vancomycin-resistant Enterococcus faecium sensitivity to isopropyl alcohol before and after implementing alcohol hand rubbing in a hospital.

A recent study reported enterococci that developed alcohol tolerance. We measured minimum inhibitory concentrations (MICs) of isopropyl alcohol against 55 vancomycin-resistant Enterococcus faecium. We did not find an increase in MICs when comparing the periods before and after the use of alcohol for hand hygiene in a hospital, and we did not find a single isolate with a MIC higher than 11.5%. We consider alcohol to still be an effective measure for hand antisepsis.

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.

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.

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.

Salvaging diabetic foot through debridement, pressure alleviation, metabolic control, and antibiotics.

There is a fatalist perception of diabetic foot because the argument of "small-vessel disease" prevails. This is the report of a cohort study of patients facing a formal recommendation for major foot amputation to assess how many can be saved with a conventional treatment, defined as debridement, pressure alleviation, metabolic control, and antibiotics. The primary efficacy measurement was the salvage of the limb at the follow-up visit between 25 and 35 days after the first consultation. The secondary efficacy measurement was the subsequent epithelization of the ulcerative lesions, following patients for up to 270 days. The cohort consisted of 105 type 2 diabetic patients; 87 (83%) had severe lesions. A total of 71 patients (68%) required hospitalization. By the intention-to-treat analysis, 89 patients (85%) avoided major amputation. A total of 88 patients were evaluated for complete epithelization, reaching median success by day 120. Overall, 51 patients (49%) underwent minor amputations. It was concluded that there is a high rate of unnecessary major foot amputations, because a diabetic foot can be salvaged across the continuum of severity when patients receive care in a multidisciplinary wound clinic.

Povidone-iodine against sodium hypochlorite as skin antiseptics in volunteers.

BACKGROUND: This study was conducted to compare the antiseptic efficacy of sodium hypochlorite of electrochemical production with that of povidone-iodine in human voluntaries. METHODS: Three areas of 25 cm(2) each were selected from the forearms; 1 was designated as control to determine the baseline bacterial count; and 2 more were selected to swab 10% povidone-iodine or 10% sodium hypochlorite. Every volunteer was studied on 3 separated occasions. Quantitative skin cultures were performed on agar plates containing a neutralizer. RESULTS: Forty-eight healthy subjects were enrolled for a total of 144 determinations for every antiseptic and control. The bacterial counts from the control areas showed a median of 1500 colony-forming units (CFU)/cm(2). For the areas treated with sodium hypochlorite, the median was 192 CFU/cm(2). For the areas treated with povidone-iodine, the median was 231 CFU/cm(2). When the colony counts for the areas treated with antiseptics were compared with those of the controls, the difference was significant (Kruskal-Wallis test (H) = 55.7, P < .001). The difference in counts between the areas treated with antiseptics was not significant (difference in z values <1960). CONCLUSION: The present study did not find differences in antiseptic action between 10% povidone iodine and 10% sodium hypochlorite.

[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.