Clinical and microbiological characteristics of community-acquired pneumonia associated with Streptococcus pneumoniae in adult patients in Mexico / Características clínicas y microbiológicas de la neumonía adquirida en la comunidad asociada con Streptococcus pneumoniae en pacientes adultos en México

The aim of this study was to assess the risk factors and clinical and microbiological characteristics of community-acquired pneumonia (CAP) in adult patients in Mexico. Streptococcus pneumoniae classified as the causative agent of CAP in adult patients and patients with invasive S. pneumoniae isolates presented to three tertiary teaching hospitals during the 15-year study period were selected. Serotyping and susceptibility testing were performed for all included isolates. Clinical and demographic data were recorded. A total of 96 patients infected with S. pneumoniae (71 with CAP, 25 with invasive disease) were included. The CAP group involved more males (74.6%) than the invasive disease group (p = 0.03). Head trauma was more common in the CAP group (21.1%) than in the invasive disease group (4.0%; p = 0.03). The most prevalent serotype was 19A, followed by serotypes 3 and 23F. After the introduction of the heptavalent conjugated pneumococcal vaccine (PCV7), the prevalence of included serotypes declined significantly; no such change was found after the introduction of the PCV13 vaccine, including in the prevalence of serotype 19A. Susceptibility to all antimicrobials tested except vancomycin declined over the study period. In conclusion, head trauma was the most common comorbidity in the CAP group. The most prevalent serotype was 19A. Decreased susceptibility to most antimicrobials tested was observed.

El objetivo de este estudio fue evaluar los factores de riesgo y las características clínicas y microbiológicas de la neumonía adquirida en la comunidad (NAC) en pacientes adultos en México. Se seleccionaron pacientes adultos con NAC con Streptococcus pneumoniae como agente causal y pacientes con aislamientos invasivos de S. pneumoniae que concurrieron a tres hospitales de enseñanza de tercer nivel durante el período de estudio de 15 anos (2000-2015). Se realizaron pruebas de serotipificación y sensibilidad con todos los aislados incluidos. Se colectaron los datos clínicos y demográficos. Se incluyeron en total 96 pacientes infectados con S. pneumoniae (71 con NAC y 25 con enfermedad invasiva). El grupo con NAC incluía más varones (74,6%) que el grupo de enfermedad invasiva (p = 0,03). El traumatismo craneoencefálico fue más frecuente en el grupo NAC (21,1%) queen el grupo con enfermedad invasiva (4,0%; p = 0,03). El serotipo más frecuente fue 19A, seguido de los serotipos 3 y 23F. Después de la introducción de la vacuna antineumocócica conjugada heptavalente (PCV7), la prevalencia de los serotipos incluidos en aquella disminuyó significativamente; no sucedió lo mismo después de la introducción de la PCV13, incluso en relación con la prevalencia del serotipo 19A. La sensibilidad a todos los antimicrobianos evaluados, excepto la vancomicina, disminuyó durante el período de estudio. En conclusión, el traumatismo craneoencefálico fue la comorbilidad más frecuente en el grupo con NAC. El serotipo más frecuente fue el 19A, y se observó disminución de la sensibilidad a la mayoría de los antimicrobianos probados a lo largo del período considerado.

Clinical and microbiological characteristics of community-acquired pneumonia associated with Streptococcus pneumoniae in adult patients in Mexico.

The aim of this study was to assess the risk factors and clinical and microbiological characteristics of community-acquired pneumonia (CAP) in adult patients in Mexico. Streptococcus pneumoniae classified as the causative agent of CAP in adult patients and patients with invasive S. pneumoniae isolates presented to three tertiary teaching hospitals during the 15-year study period were selected. Serotyping and susceptibility testing were performed for all included isolates. Clinical and demographic data were recorded. A total of 96 patients infected with S. pneumoniae (71 with CAP, 25 with invasive disease) were included. The CAP group involved more males (74.6%) than the invasive disease group (p=0.03). Head trauma was more common in the CAP group (21.1%) than in the invasive disease group (4.0%; p=0.03). The most prevalent serotype was 19A, followed by serotypes 3 and 23F. After the introduction of the heptavalent conjugated pneumococcal vaccine (PCV7), the prevalence of included serotypes declined significantly; no such change was found after the introduction of the PCV13 vaccine, including in the prevalence of serotype 19A. Susceptibility to all antimicrobials tested except vancomycin declined over the study period. In conclusion, head trauma was the most common comorbidity in the CAP group. The most prevalent serotype was 19A. Decreased susceptibility to most antimicrobials tested was observed.

MGIT and other methods for diagnosing tuberculosis in a private hospital system with low incidence / MGIT y otros métodos para diagnosticar tuberculosis en un sistema hospitalario privado con baja incidencia

Background: Tuberculosis (TB) is still a threat to public health; in 2014 caused 1.5 million deaths worldwide; in hospitals where the prevalence of TB is low, it is appropriate to evaluate the effectiveness of tests to diagnose it. Methods: We reviewed reports of airway clinical specimens sent for studies of tuberculosis to the microbiology laboratory from Tec Salud System private hospitals (400 beds) in the metropolitan area of ​​Monterrey, NL, from May 2012 to December 2015. In conjunction with Ziehl-Neelsen (ZN) stain, and solid Lowenstein-Jensen medium (LJ), our laboratory resources also include fluorescent LED microscopy (Carl Zeiss Microscopy Products), MGIT 320 (Mycobacteria Growth Indicator Tube liquid culture detection system, Becton Dickinson), and recently incorporated a real-time PCR system the Xpert MTB/RIF test (Cepheid, Sunnyvale, CA). Results: In 731 respiratory specimens from 510 patients, M. tuberculosis was isolated from 78 samples belonging to 50 patients on LJ and MGIT LJ 42 (84%) and MGIT 49, (98%) of the samples. From 41 patients identified, 26 (63.4%) were positive to fluorescein, and 25 (60.9%) with Ziehl-Neelsen stain. Real time PCR (Xpert TB) was positive in 13 out of 17 patient-airway samples (76.4%). Conclusions: Usefulness of liquid culture (MGIT) and solid culture (LJ) is shown; the first can significantly cut incubation times.

Introducción: la tuberculosis (TB) aún es una amenaza para la salud pública; en 2014 causó 1.5 millones de muertes a nivel mundial. En hospitales donde la prevalencia de TB es baja, resulta conveniente evaluar la efectividad de las pruebas para diagnosticarla. Métodos: revisamos los informes de resultados de muestras de vías respiratorias enviadas para estudios de tuberculosis de mayo de 2012 a diciembre de 2015 al laboratorio de Microbiología del Sistema Tec Salud (400 camas) en el área metropolitana de Monterrey. Además de la tinción de Ziehl-Neelsen (ZN) y cultivo sólido de Lowenstein-Jensen (LJ); se realizó fluorescencia LED, cultivo en medio líquido MGIT 320 y más recientemente el Xpert MTB/RIF test. Resultados: se cultivaron en LJ y MGIT 731 muestras de vías respiratorias de 510 pacientes; en las muestras de 50 de ellos se identificó M. tuberculosis, 49 en MGIT (98%) y 42 en LJ (84%). De las muestras correspondientes a 41 pacientes, 26 (63.4%) fueron positivas con fluoresceína, y 25 (60.9%) con ZN. En las muestras de 17 pacientes se hizo PCR en tiempo real (Xpert MTB), 13 fueron positivas (76.4%). Conclusiones: se demuestra la utilidad del cultivo en medio liquido (MGIT) y del LJ en medio sólido; el primero, además de ser más sensible, permite acortar en forma importante los tiempos de incubación.

[Role of anaerobic blood culture in the simultaneous blood culture taking for the diagnosis of bacteremia]. / Papel del hemocultivo anaeróbico en la toma simultánea de hemocultivos para el diagnóstico de bacteriemia.

BACKGROUND: Harboring a high mortality, the incidence of sepsis is increasing; thus detection, identification and susceptibility tests of the involved microorganisms become urgent. METHODS: We reviewed the records from January 2013 until July 2014 of a total of 4110 blood culture bottles taken from adult patients in a private tertiary hospital. RESULTS: Growth of microorganisms was observed in 559 bottles (12.6%). We emphasize that 2648 blood cultures (60%) were taken in two paired aerobic and anaerobic bottles drawn at the same time (1324 pairs); from these, growth was observed in 182 inoculated bottles drawn from two different sites at the same time from 135 patients (13.7%). In 86 pairs of bottles with samples from 54 patients (40%), growth occurred only in the aerobic blood culture bottles. Also, growth of microorganisms was observed only in anaerobic bottles in 24 pairs (13.19%), corresponding to 21 patients (15.5%, p<0.05%). In blood cultures from 32 out of 60 patients with growth in both media (53%), microbial growth was detected first in the anaerobic bottle. CONCLUSIONS: The usefulness of blood cultures for anaerobes for the identification of obligate anaerobic bacteremia which rarely occur is low (2.2% of patients with bacteremia); however, in 15.55% of the patients the risk of completely overlook bacteremia was present, and in 53% of patients with positive cultures, bacteremia was established earlier, and thus permitted earlier and accurate decision making.

Introducción: la frecuencia de la septicemia va en aumento y su mortalidad es alta; por lo tanto, su detección, la identificación del microorganismo causal y su susceptibilidad son perentorias. Metodos: se revisaron los registros de 4110 botellas de cultivo de sangre obtenida de enero de 2013 a julio de 2014 de pacientes adultos en un hospital privado de tercer nivel. Resultados: se observó crecimiento de microorganismos en 559 cultivos (12.6 %). En 2648 hemocultivos (60 %) inoculados en pares de frascos uno con medio aeróbico y el otro anaeróbico (1324 sets), se detectó crecimiento en 182 frascos a los que les fueron inoculadas las muestras tomadas al mismo tiempo a 135 pacientes (13.7 %). En 86 pares de frascos con las muestras de 54 pacientes (40 %), el crecimiento solamente se dio en el frasco aeróbico (47.5 %); en 24 pares de frascos (13.19 %) tomados a 21 pacientes (15.5 %, p < 0.05), solamente hubo crecimiento en el frasco anaeróbico. En los hemocultivos de 32 de 60 pacientes con crecimiento en ambos frascos (53 %), el crecimiento se detectó primero en el frasco anaeróbico. Conclusiones: los hemocultivos anaeróbicos tienen una utilidad baja para la detección de bacteriemias por anaerobios estrictos; no obstante, en el 15.55 % de los pacientes estuvo presente el riesgo de pasar por alto la presencia de bacteriemia, y en 53 % de los pacientes con hemocultivos positivos, el diagnóstico de bacteriemia pudo establecerse de manera más temprana, lo que permitió anticipar con mejor precisión la toma de decisiones.

[Necrotizing fasciitis, myositis, arthritis, and streptococcal toxic shock syndrome caused by group G Streptococcus. Report of one case]. / Fascitis necrotizante, miositis y síndrome de choque tóxico secundario a estreptococo del grupo G. Reporte de un caso.

BACKGROUND: Necrotizing fasciitis (NF), myositis, and streptococcal toxic shock syndrome (STSS) associated with group G ß-hemolytic streptococcus (GGS) occasionally coincide. CLINICAL CASE: We describe a case of GGS simultaneously occurring with NF, myositis, arthritis, and STSS in an 83-year-old woman with sequelae of cerebrovascular disease, hospitalized after two days of fever and with a painful swollen left foot. She was hypotensive, her foot had purplish discoloration, which showed blisters spreading to the lower third of the leg, and no crepitus was present. Fluid, vasopressive support, tigecyclin, and clindamycin were used. Debrided tissue and fluid aspirated from the knee joint revealed Gram-positive cocci. The patient developed renal and respiratory failure on the fifth day, requiring support. She underwent amputation above the knee of the left leg, after which her condition improved. She was discharged one month later. CONCLUSION: GGS can cause life-threatening infections such as NF, myositis, and/or STSS. GGS usually afflicts aging patients with comorbid states, and occasionally healthy subjects.

Introducción: ocasionalmente concurren la fascitis necrotizante (FN), con miositis, y síndrome de choque tóxico post-estreptocócico (SSTE) asociados con infección por estreptococo ß-hemolítico del grupo G (EGG). Caso clínico: presentamos un caso de infección en el que concurren simultáneamente FN, miositis, artritis y SSTE en una mujer de 83 años con secuelas de enfermedad cerebrovascular, hospitalizada tras dos días de fiebre y dolor, así como hinchazón del pie izquierdo. Se encontraba hipotensa y el pie mostraba coloración púrpura con flictenas que se extendían hacia el tercio inferior de la pierna; no había crepitación a la presión digital. Se empleó hidratación parenteral, vasopresores, tigeciclina y clindamicina. Tanto el tejido desbridado como el líquido aspirado de la articulación de la rodilla revelaron cocos gram positivos. Al quinto día la paciente desarrolló falla renal y respiratoria que requirieron de apoyo. La paciente fue sometida a amputación supracondílea de la pierna izquierda; después de eso, su condición mejoró. Un mes después fue dada de alta. Conclusiones: el EGG puede causar infecciones potencialmente mortales, como FN, miositis, y/o SSTE. El EGG por lo general afecta a pacientes ancianos con estados comórbidos y ocasionalmente a sujetos sanos.

[Necrotizing fasciitis and group A streptococcal toxic shock syndrome in two patients without risk factors]. / Fascitis necrotizante y choque tóxico en infección por estreptococo grupo A.

Necrotizing fasciitis associated to group A streptococcus (S. pyogenes) infection is a deep-seated infection of the subcutaneous tissue that results in progressive destruction of fascia and fat, with a high mortality rate due to a rapid progression of the illness to shock and multiple organ dysfunction. The challenge is to perform a prompt diagnosis because it is often confused with a minor soft-tissue infection. This infection should be aggressively treated with systemic antimicrobials, surgical debridement, and critical care. We present two cases of necrotizing fasciitis associated to infection with Streptococcus pyogenes patients developed myonecrosis and toxic shock syndrome within the following 24 hours after admission. In addition, we reviewed the pathogenic mechanism, diagnosis and treatment of this syndrome and discuss published treatment recommendations.

[Catheter-associated bloodstream infections. Review of five-year surveillance among hospitalized patients]. / Bacteriemia asociada con catéter venoso central. Revisión de cinco años de vigilancia en pacientes hospitalizados.

BACKGROUND: Catheter related infections (CRI) and bloodstream infection (BSI) associated to central venous catheter (CVC) is cause of frequent hospital-acquired infection (HAI) and a major reason of morbidity and mortality among patients and it is itself an indicator of quality health care. OBJECTIVE: To determine the incidence of CRI and BSI and to identify the hospital areas where they occurred over a five-year period. METHODS: A prospective study from 2004 to 2008 in a population of hospitalized patients who required the use of CVC was made. The HAI team detected the appearance of CRI during a daily routine surveillance. RESULTS: During the period of observation, 176 BSI were detected, accounting for 11 % of all HAI, and represented the third place in frequency. Incidence rate for 1000 catheter-days varied from 2.7 in 2006 to 5.4 in 2008; 57 % of these BSI were detected in the intensive care units. Candida spp. accounted as the more frequently isolated microorganism with predominance of C. parapsilosis. CONCLUSIONS: Our results and the incidence rate found in our study occurred within rates established in other studies.

Cutaneous zygomycosis in immunocompetent patients in Mexico.

We report three cases of traumatic cutaneous zygomycosis related to soil-contaminated skin lesions occurring after automobile accidents in individuals with no underlying disorders, which showed delayed development and diagnosis in comparison with typical zygomycosis cutaneous lesions.

[Antibiotic resistance of Escherichia coli from community-acquired urinary tract infections. What antimicrobial to use?]. / Resistencia antimicrobiana en la infección urinaria por Escherichia coli adquirida en la comunidad. Cuál antibiótico voy a usar?

OBJECTIVE: Determine antibiotic resistance of community-acquired uropathogen Escherichia coli and infer therapeutic options. MATERIAL AND METHODS: E. coli strains isolated from urine during a one-year period were studied. Identification and susceptibility tests were performed. RESULTS: A total of 652 isolates were included from patients in two institutions, a healthcare clinic 303 (46.5%) and a hospital 349 ( 53.5%). The antimicrobials with higher resistance rates were ampicillin 67.2%, trimethoprim-sulfametoxazole 59.2%, cefazolin 35.6% and ciprofloxacin 24.7%. CONCLUSIONS: Resistance to trimethoprim-sulfamethoxazole and ciprofloxacin used for empiric treatment in community urinary infections is high, and there are few available treatment options.

Resistencia antimicrobiana en la infección urinaria por Escherichia coli adquirida en la comunidad: ¿cuál antibiótico voy a usar? / Antibiotic resistance of Escherichia coli from community-acquired urinary tract infections: what antimicrobial to use?

OBJETIVO: Determinar la resistencia del uropatógeno comunitario más frecuente, Escherichia coli, a diversos antimicrobianos y deducir opciones de manejo empírico. MATERIAL Y MÉTODOS: Del 14 de julio de 2005 al 13 julio de 2006 se estudiaron cepas de Escherichia coli aisladas de urocultivos de pacientes que asistieron a la consulta externa de la Clínica Nova y del Hospital San José, en Monterrey, Nuevo León, México. Se identificó la bacteria y se determinó susceptibilidad a antibióticos mediante método automatizado. Se compararon los resultados entre las dos instituciones y la frecuencia de resistencia a antimicrobianos entre mujeres de entre 15 a 50 años de edad y > 50. RESULTADOS: Se analizaron 652 urocultivos: 303 (46.5 por ciento) de Clínica Nova y 349 (53.5 por ciento) del Hospital San José. Las cepas aisladas fueron resistentes a ampicilina, en 67.2 por ciento; a trimetoprim-sulfametoxazol, en 59.2 por ciento; a cefazolina, en 35.6 por ciento, y a ciprofloxacino, en 24.7 por ciento. CONCLUSIONES: La resistencia a trimetoprim-sulfametoxazol y ciprofloxacino, considerados de elección en el manejo empírico de las infecciones de vías urinarias adquiridas en la comunidad, es alta. Las opciones de manejo son pocas.

OBJECTIVE: Determine antibiotic resistance of community-acquired uropathogen Escherichia coli and infer therapeutic options. MATERIAL AND METHODS: E. coli strains isolated from urine during a one-year period were studied. Identification and susceptibility tests were performed. RESULTS: A total of 652 isolates were included from patients in two institutions, a healthcare clinic 303 (46.5 percent) and a hospital 349 ( 53.5 percent). The antimicrobials with higher resistance rates were ampicillin 67.2 percent, trimethoprim-sulfametoxazole 59.2 percent, cefazolin 35.6 percent and ciprofloxacin 24.7 percent. CONCLUSIONS: Resistance to trimethoprim-sulfamethoxazole and ciprofloxacin used for empiric treatment in community urinary infections is high, and there are few available treatment options.