First nosocomial outbreak of SME-4-producing Serratia marcescens in South America / Primer brote nosocomial por Serratia marcescens productora de SME-4en Sudamérica

Abstract Carbapenemase-producing-Serratia marcescens isolates, although infrequent, are considered important nosocomial pathogens due to their intrinsic resistance to polymyxins, which limits therapeutic options. We describe a nosocomial outbreak of SME-4-producing S. marcescens in Buenos Aires city which, in our knowledge, represents the first one in South America.

Resumen Los aislamientos de origen nosocomial de Serratia marcescens productores de car-bapenemasa, si bien son infrecuentes, son considerados importantes patógenos debido a su resistencia intrínseca a las polimixinas, lo cual limita aún más las opciones terapéuticas. En este trabajo se describe un brote nosocomial causado por S. marcescens portadora de car-bapenemasa de tipo SME-4 en la Ciudad de Buenos Aires, el cual representaría el primero en Sudamérica.

Genotyping Influenza Virus by Next-Generation Deep Sequencing in Clinical Specimens

Rapid and accurate identification of an influenza outbreak is essential for patient care and treatment. We describe a next-generation sequencing (NGS)-based, unbiased deep sequencing method in clinical specimens to investigate an influenza outbreak. Nasopharyngeal swabs from patients were collected for molecular epidemiological analysis. Total RNA was sequenced by using the NGS technology as paired-end 250 bp reads. Total of 7 to 12 million reads were obtained. After mapping to the human reference genome, we analyzed the 3-4% of reads that originated from a non-human source. A BLAST search of the contigs reconstructed de novo revealed high sequence similarity with that of the pandemic H1N1 virus. In the phylogenetic analysis, the HA gene of our samples clustered closely with that of A/Senegal/VR785/2010(H1N1), A/Wisconsin/11/2013(H1N1), and A/Korea/01/2009(H1N1), and the NA gene of our samples clustered closely with A/Wisconsin/11/2013(H1N1). This study suggests that NGS-based unbiased sequencing can be effectively applied to investigate molecular characteristics of nosocomial influenza outbreak by using clinical specimens such as nasopharyngeal swabs.

Brote de infección nosocomial por Serratia marcescens asociado a contaminación intrínseca de clorhexidina acuosa / Outbreak due to Serratia marcescens associated with intrinsic contamination of aqueous chlorhexidine

Serratia marcescens is a widely distributed gram-negative rod, often associated to nosocomial infections. Some outbreaks linked to contaminated antiseptic solutions have been reported. In this study we report a nosocomial outbreak of surgical site infection and catheter insertion site infection due to S. marcescens. 33 patients with positive cultures were studied after an index case was identified. Epidemiological, microbiological and molecular analysis demostrated an intrinsic contamination of alcohol free chlorhexidine solution as causal factor. Positive cultures were associated with 13 clinical infections, 9 colonized patients, 6 pseudobacteremia episodes and 5 patients without documented exposure. Hospital and national recall of contaminated chlorhexidine solution was performed after this study. Intrinsic contamination of antiseptic solutions is an infrequent cause of nosocomial infections with major epidemiological relevance.

Serratia marcescens es un bacilo gramnegativo de amplia distribución, frecuentemente asociado a infecciones nosocomiales. Se han descrito brotes asociados a la contaminación de diversas soluciones antisépticas. Describimos a continuación un brote de infección de sitio operatorio (ISO) y de infección de sitio de inserción de catéter vascular (ISC) por S. marcescens. A raíz de un caso índice se estudió un total de 33 pacientes con cultivo positivo para S. marcescens. El análisis epidemiológico, microbiológico y molecular logró demostrar la contaminación intrínseca de un lote de clorhexidina acuosa, como fuente común de exposición. Las muestras positivas correspondieron a 13 infecciones clínicas, nueve colonizaciones, seis pseudo-bacteriemias y cinco pacientes sin exposición demostrada. Los resultados de este estudio determinaron el retiro del producto de la institución y posteriormente a nivel nacional. La contaminación intrínseca de antisépticos es una causa poco frecuente de brotes de infecciones nosocomiales cuya identificación posee un gran impacto epidemiológico.

Biofilm production by multiresistant Corynebacterium striatum associated with nosocomial outbreak

Corynebacterium striatum is a potentially pathogenic microorganism that causes nosocomial outbreaks. However, little is known about its virulence factors that may contribute to healthcare-associated infections (HAIs). We investigated the biofilm production on abiotic surfaces of multidrug-resistant (MDR) and multidrug-susceptible (MDS) strains of C. striatum of pulsed-field gel electrophoresis types I-MDR, II-MDR, III-MDS and IV-MDS isolated during a nosocomial outbreak in Rio de Janeiro, Brazil. The results showed that C. striatum was able to adhere to hydrophilic and hydrophobic abiotic surfaces. The C. striatum 1987/I-MDR strain, predominantly isolated from patients undergoing endotracheal intubation procedures, showed the greatest ability to adhere to all surfaces. C. striatum bound fibrinogen to its surface, which contributed to biofilm formation. Scanning electron microscopy showed the production of mature biofilms on polyurethane catheters by all pulsotypes. In conclusion, biofilm production may contribute to the establishment of HAIs caused by C. striatum.

Clonal multidrug-resistant Corynebacterium striatum within a nosocomial environment, Rio de Janeiro, Brazil

Corynebacterium striatum is a potentially pathogenic microorganism with the ability to produce outbreaks of nosocomial infections. Here, we document a nosocomial outbreak caused by multidrug-resistant (MDR) C. striatum in Rio de Janeiro, Brazil. C. striatum identification was confirmed by 16S rRNA and rpoB gene sequencing. Fifteen C. striatum strains were isolated from adults (half of whom were 50 years of age and older). C. striatum was mostly isolated in pure culture from tracheal aspirates of patients undergoing endotracheal intubation procedures. The analysis by pulsed-field gel electrophoresis (PFGE) indicated the presence of four PFGE profiles, including two related clones of MDR strains (PFGE I and II). The data demonstrated the predominance of PFGE type I, comprising 11 MDR isolates that were mostly isolated from intensive care units and surgical wards. A potential causal link between death and MDR C. striatum (PFGE types I and II) infection was observed in five cases.

Outbreak of carbapenem-resistant Klebsiella pneumoniae: two-year epidemiologic follow-up in a tertiary hospital

This study describes a carbapenem-resistant Klebsiella pneumoniae (CRKP) outbreak that occurred from October 2008-December 2010. Polymerase chain reaction assays were performed to detect the blaKPC gene and molecular typing was performed using pulsed-field gel electrophoresis (PFGE). There were 33 CRKP infections; PFGE revealed five genotypes: genotype A in five (15%), B in 18 (55%), C in eight (24%) and two unique profiles. Genotype B was disseminated in all hospital units and belonged to the same clone identified in 11 different hospitals in the state of São Paulo. Sixteen (48%) patients died. Seven isolates (21%) were resistant to polymyxin B and 45% were resistant to tigecycline and amikacin.

Molecular investigation of a fungemia outbreak due to Candida parapsilosis in an intensive care unit

We investigated a nosocomial cluster of four Candida parapsilosis fungemia episodes that occurred in a neurological intensive care unit over a two-week period. The four infected patients had received parenteral nutrition through central lines, and all four had catheter-related candidemia. All of the isolates were susceptible to all of the antifungals tested, including amphotericin B, fluconazole, voriconazole, and caspofungin. They had strictly related fingerprints, based on randomly amplified polymorphic DNA analysis. Additional DNA sequencing data revealed that they were same strain. Although no isolate of Candida parapsilosis was recovered from other clinical, surveillance, or environmental samples, nosocomial spread of this yeast ceased, following the reinforcement of infection-control measures. Candida parapsilosis may require an intravascular foreign body to cause fungemia, but this outbreak shows that it can be transmitted nosocomially and can cause epidemics.

Brote de sarna en un hospital terciario a partir de un caso de sarna costrosa / An outbreak of scabies in a tertiary-care hospital from a crusted scabies case

Realizamos el estudio epidemiológico de un brote de sarna ocurrido en un hospital terciario, a partir de un caso de sarna costrosa, en febrero de 2005. Detectamos diez casos secundarios; ocho en el personal de salud y dos en pacientes hospitalizados, con una tasa de ataque de 4,1 por ciento. A diferencia de otros brotes, el diagnóstico de sarna costrosa se hizo al ingreso del caso primario al hospital. Las causas del brote fueron: adherencia deficiente a las medidas de aislamiento de contacto, permanencia prolongada del caso primario en sala compartida, y retardo en el inicio del tratamiento específico. Las principales medidas de control fueron: alertar a los servicios sobre el brote, realizar vigilancia epidemiológica, coordinación con la Dirección del Hospital y el Departamento de Salud Ocupacional, capacitar al personal de salud en las medidas de control, instaurar medidas de aislamiento y tratar a los casos y sus contactos con permetrina 5 por ciento loción tópica.

In February 2005 we performed an epidemiological study of an outbreak of scabies in a tertiary-care hospital which started from a crusted scabies case. We detected 10 secondary cases, 8 in healthcare workers and 2 in hospitalized patients. The attack rate was 4.1 percent. In contrast to previously described outbreaks, the crusted scabies case was recognized at admission. The outbreak causes were: lacking adherence to contact precautions, long stay of the primary case in the hospital ward and delay of specific treatment. The main control measures were: alerting the hospital services about the outbreak, performing epidemiologic surveillance, coordinating with the Hospital Direction and the Occupational Health Department, education of healthcare workers in control measures, implementation of isolation measures and treatment of cases and contacts with 5 percent permethrin topical lotion.

Brote de bacteriemia nosocomial y colonización por Serratia marcescens en una Unidad de Cuidado Intensivo Neonatal / Nosocomial bacteremia and gastrointestinal tract colonization outbreak of Serratia marcescens in Neonatal Intensive Care Unit

Introducción. Se presenta la descripción de un brote de bacteriemia y colonización gastrointestinal nosocornial por Serratia marcescens en una Unidad de Cuidado Intensivo Neonatal (UCIN) de un hospital de tercer nivel. Material y métodos. El período epidémico fue considerado del 17 de mayo al 17 de junio de 2006. Se definió como caso a cualquier paciente con cultivo positivo para S. marcescens durante el período epidémico, ya que no se había identificado ningún cultivo positivo para esta bacteria en 6 meses de período pre-epidémico. Para identificar factores de riesgo de desarrollo de infección/colonización por S. mareescens, se compararon los casos con pacientes controles, definidos como aquéllos expuestos durante el período del brote sin aislamiento de esta bacteria. Todos los aislamientos de microorganismos fueron genotipificados por restricción con endonucleasa y electroforesis en gel por campos pulsados (PFGE). Resultados. Durante el período epidémico se identificaron 7 pacientes con cultivos positivos para S. marcescens y 12 controles. El paciente índice tuvo hemocultivo positivo y cuadro clínico de bacteriemia nosocomial, seguido por un caso de ventriculitis con cultivo positivo para S. marcescens en líquido cefalorraquídeo. Los otros 5 casos tuvieron aislamiento de S. marcescens en coprocultivos. Los cultivos de soluciones intravenosas y superficies inanimadas fueron negativos. El análisis univariado demostró que los pacientes con infección/colonización por S. marcescens tuvieron una estancia hospitalaria más prolongada (52 vs 27.9 días, P < 0.05), mayor frecuencia de alimentación enteral y presencia de sonda orogástrica al compararse con los controles. El patrón de PFGE fue idéntico en todos los aislamientos de S. mareescens. El reforzamiento de precauciones de contacto, incluyendo lavado de manos, además de cierre temporal de la UCIN, controló el problema de brote. Conclusión. El análisis epidemiológico complementado con técnicas de epidemiología molecular en este estudio aporta evidencia de un brote de 2 casos de bacteriemia nosocomial por transmisión cruzada de S. marcescens a través de un reservorio gastrointestinal. Estos hallazgos confirman la importancia que tienen las medidas de precauciones de contacto como el lavado de manos en el manejo de pacientes de la UCIN para prevenir infecciones nosocomiales y control de brotes.

Introduction. We investigated an outbreak of Serratia marcescens bloodstream infection (BSI)/colonization in patients from a Neonatal Intensive Care Unit (NICU) in a tertiary care pediatric Hospital. Material and methods. May 17 through June 17, 2006 was considered as the study period. A case was defined as any patient with S. marcescens-positive culture in the NICU during the outbreak period because no S. marcescens was identified in this area within 6 month of pre-epidemic period. To identify risk factors we compared patients with S. marcescens positive-cultures with controls exposed to the cases during the outbreak period without positive cultures. Genotyping of all S. marcescens isolates were evaluated by restriction endonuclease and pulsed-field gel electrophoresis (PFGE). Results. Seven S. marcescens positive cultures were identified; the index case had a positive blood culture with diagnosis of BSI, followed by a patient with CSF positive culture with diagnosis of ventriculitis and BSI. The remaining 5 cases had concurrent S. marcescens isolates from stool cultures (colonization). Environmental cultures (water, IV solutions and inanimate surfaces) were negative for these bacteria. According to univariate analysis, patients with S. marcescens stayed in the NICU longer than controls (52 vs 27.9 days, P < 0.05), they were more likely to have an orogastric tube in place and to receive enteral nutrition. All the S. marcescens had an identical pattern of PFGE analysis. Contact precaution, including hand washing, was reinforced in addition to temporary closing of the NICU in order to control the outbreak. Conclusions. This outbreak of S. marcescens was studied using epidemiological analysis and molecular biology techniques, confirming cross-transmission between cases associated to a possible gastrointestinal reservoir. Our findings underscore the importance of hand hygiene and other contact precaution methods in hospital settings, such as NICU.

Outbreak of Nosocomial Urinary Tract Infections caused by Candida spp / 병원감염관리

BACKGROUND: Urinary tract is the most common site of nosocomial infections, accounting for 35% of all nosocomial infections. About 80-90% of these urinary tract infections are associated with urethral catheter insertion. Recently, we experienced an outbreak of nosocomial UTI (urinary tract infection) caused by Candida spp. in the surgical ICU (SICU) and we investigated the cause of UTI outbreak. METHODS: We collected data from clinical records and observed the current methods of care of urethral catheters in the SlCU. During the outbreak, we investigated the current procedures and maintenance care of urethral catheter insertion and educated the staff on the correct methods of the catheter insertion and care. We performed surveillance cultures of unused new urine bags, RESULTS: Between May 2000 and June 2000, 17 Candida spp. strains were isolated from urines of 17 patients hospitalized in the SICU of National Health Insurance Corporation Ilsan Hospital. All infections were attributed to the care of urethral catheter insertion and contaminated bags. We identified that routine bladder irrigation and emptying urine to a common urinal have been done incorrectly during the outbreak period. Rodotorula spp. was isolated from 4 urine bags (50% contamination rate) out of 8 unused new urine bags by surveillance cultures. CONCLUSION: The causes of the UTI outbreak caused by Candida spp. was terminated by outbreak investigation and change of contaminated urine bag.

Outbreak of Nosocomial Urinary Tract Infections caused by Multidrug-Resistant Pseudomonas aeruginosa / 병원감염관리

BACKGROUND: Nosocomial urinary tract infection (UTI) accounts for 35% of the nosocomial infection and 80-90% of them are associated with urethral catheters. Recently, we experienced an outbreak of nosocomial UTI caused by multidrug-resistant Pseudomonas aeruginosa in neurosurgical intensive care unit (NSICU). METHODS: We investigated clinical records of the patients and observed the methods of care of urethral catheters in NSICU. Identification of P. aeruginose was done by API NE (API system; bioMerieux, France) and antibiotic susceptibility tests were done by disk diffusion method. Random Amplification of Polymorphic DNA (RAPD) assay was used as a genotyping method. RESULTS: Between November 1997 and January 1998, 11 P. aeruginosa strains were isolated from the urine of 11 patients hospitalized in NSICU of Kangnam St. Mary's Hospital. Routine regular bladder irrigation, and emptying urine with common urinal had been done falsely. Antibiogram of the isolates showed resistance to multiple antibiotics including imipenem, gentamicin. amikacin, piperacillin, ciprofloxacin, ceftazidime, and cefoperazone/sulbactam. RAPD of the outbreak strains showed clonal relatedness, which was different from those of other clinical strains, We instructed all the health care workers to stop bladder Irrigation, and to use the separate urinals for each patient. Thereafter, no further case of P. aeruginosa UTI has occurred. CONCLUSION: An outbreak of UTI, caused by a single clone of P. aeruginosa, was confirmed by RAPD and was eradicated after correction of false practice on care-of urinary catheter.

Molecular Epidemiology of Methicillin-resistant Staphylococcus aureus Outbreak by Plasmid Restriction Analysis / 대한임상미생물학회지

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major cause of nosocomial infection and a molecular typing is necessary for proper epidemiologic investigations of sources and moles of spread in an outbreak. An nosocomial outbreak of MRSA in a neonatal intensive care unit at Ewha Womans University Mokdong Hospital was suspected. To investigate the clonality of isolates and control the spread of nosocomial outbreak, we performed plasmid restriction analysis of MRSA isolates from patients and medical staffs. METHODS: We studied 7 MRSA strains (umbilicus 4, blood 1, urine 1 and pus 1) from patients in a neonatal intensive care unit and the MRSA strains from nares and hands surveillance cultures of 26 medical staffs (4 medical doctors and 22 nurses). All MRSA strains were tested for antimicrobial susceptibility and plasmic analysis after EcoRI restriction. We analyzed the plasmid patterns of MRSA isolated from patients and compared with those from medical staffs. RESULTS: Ten MRSA strains (from 7 nares and 3 hands) were isolated from surveillance cultures of 26 medical staffs. Seven out of 10 MRSA strains from medical staffs revealed identical pattern of antibiogram which was the same pattern in all 7 MRSA strains from seven patients. Plasmid restriction patterns were classified 6 groups from A to F showing 2-10 bands. Six out of 7 MRSA strains from the patients showed group A(A1 5, A31) and 5 out of 10 MRSA strains from the medical staffs showed group A(A1 1, A21, A32, A41) and remainders showed different plasmid restriction analysis patterns. CONCLUSIONS: These results suggest that plasmid restriction analysis is a rapid, inexpensive, and good discriminating molecular typing of MRSA outbreak and is useful for the epidemiologic investigation of MRSA outbreaks in the clinical laboratory.

Outbreak of Multi-resistant Acinetobecter baumannii in Intensive Care Unit of a Newly Opened Hospital / 병원감염관리

BACKGROUND: A sustained outbreak of multi-resistant Acinetobacter baumannii has been noticed in intensive care unit (ICU) of a newly opened hospital. METHODS: We retrospectively studied 72 patients in the ICU whose specimen grew A. baumannii from March to December 1995. To identify risk factors for infection, a case control study was conducted. Comparing clinical characteristics of 19 infected patients with those of 53 colonized cases. Environmental culture was performed in January 1996 to identify the source of infection. We analyzed antibiotic susceptibility of the isolates, and ribotyping was performed with 52 isolates. RESULTS: Nineteen out of 72 patients developed disease: primary sepsis 2, catheter related infection 2, catheter related infection and pneumonia 2, wound infection 5, wound infection and sepsis 2, pneumonia 6. On comparison of clinical characteristics between the infected and colonized groups, central venous catheterization was a significant risk factor for development of disease by A. baumannii (P<0.05) and duration of lCU stay was a factor independently associated with A. baumannii infection by logistic regression analysis. An epidemiologic investigation failed to identify the source of infection, but we found 2 of 3 sinks in lCU were heavily contaminated by the organism. Antibiogram of the isolates showed a multi-drug resistance including amikacin, which was found to increase gradually during the course of the outbreak. Ribotyping showed 3 major subtypes: 2A (18 isolates) 2B (16) 2B'(13) and other types (5). CONCLUSION: The findings from this study support the reports from many parts of the world that A. baumannii plays an increasingly important role as one of the major nosocomial pathogens.

Outbreak of Multi-resistant Acinetobecter baumannii in Intensive Care Unit of a Newly Opened Hospital / 병원감염관리

BACKGROUND: A sustained outbreak of multi-resistant Acinetobacter baumannii has been noticed in intensive care unit (ICU) of a newly opened hospital. METHODS: We retrospectively studied 72 patients in the ICU whose specimen grew A. baumannii from March to December 1995. To identify risk factors for infection, a case control study was conducted. Comparing clinical characteristics of 19 infected patients with those of 53 colonized cases. Environmental culture was performed in January 1996 to identify the source of infection. We analyzed antibiotic susceptibility of the isolates, and ribotyping was performed with 52 isolates. RESULTS: Nineteen out of 72 patients developed disease: primary sepsis 2, catheter related infection 2, catheter related infection and pneumonia 2, wound infection 5, wound infection and sepsis 2, pneumonia 6. On comparison of clinical characteristics between the infected and colonized groups, central venous catheterization was a significant risk factor for development of disease by A. baumannii (P<0.05) and duration of lCU stay was a factor independently associated with A. baumannii infection by logistic regression analysis. An epidemiologic investigation failed to identify the source of infection, but we found 2 of 3 sinks in lCU were heavily contaminated by the organism. Antibiogram of the isolates showed a multi-drug resistance including amikacin, which was found to increase gradually during the course of the outbreak. Ribotyping showed 3 major subtypes: 2A (18 isolates) 2B (16) 2B'(13) and other types (5). CONCLUSION: The findings from this study support the reports from many parts of the world that A. baumannii plays an increasingly important role as one of the major nosocomial pathogens.