RESUMEN
Pharyngeal colonization by Streptococcus pneumoniae was evaluated in 103 human immunodeficiency virus (HIV)-infected subjects (<200 CD4 cells/microL, 57; > or = 200 CD4 cells/microL, 46) and 39 non-HIV-infected controls who were participants in a vaccine study. At baseline, 7%, 20%, and 10% of subjects in the <200 and > or = 200 CD4 cell groups and in the control group were colonized with S. pneumoniae: Rates at 6 months were 23%, 22%, and 0%, respectively. Of 34 isolates from HIV-infected subjects, 25 were penicillin-resistant and 19 were resistant to > or = 3 antimicrobials; of 8 isolates from controls, 1 was resistant. Resistance to trimethoprim-sulfamethoxazole was significantly higher among HIV-infected subjects with <200 CD4 cells/microL than in those with more CD4 cells. Polymerase chain reaction DNA analysis with BOX primers demonstrated that 12 HIV-infected subjects were persistently colonized with the same S. pneumoniae strain for > or = 1 month compared with none of the controls. HIV-infected subjects were more likely to be persistent pneumococcal carriers and to carry antibiotic-resistant isolates than were non-HIV-infected subjects.
Asunto(s)
Infecciones por VIH/microbiología , Faringitis/microbiología , Infecciones Estreptocócicas/complicaciones , Streptococcus pneumoniae/patogenicidad , Adulto , Recuento de Linfocito CD4 , Portador Sano , ADN Bacteriano/análisis , Farmacorresistencia Microbiana , Infecciones por VIH/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Faringe/microbiología , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Infecciones Estreptocócicas/microbiologíaRESUMEN
OBJECTIVE: To investigate an outbreak of Burkholderia (formerly Pseudomonas) cepacia respiratory tract colonization and infection in mechanically ventilated patients. DESIGN: A retrospective case-control and bacteriologic study. SETTING: Veterans Affairs medical center. PATIENTS: 42 mechanically ventilated patients who developed respiratory tract colonization or infection with B. cepacia and 135 ventilator-dependent controls who were not colonized and did not develop infections. MEASUREMENTS: Clinical and demographic data; benzalkonium chloride concentrations and pH levels in albuterol sulfate solutions; repetitive-element polymerase chain reaction (PCR)-mediated molecular fingerprinting on eight patient isolates and three environmental B. cepacia isolates that were available for study. RESULTS: 42 patients had B. cepacia respiratory tract colonization or infection. Observation of intensive care unit and respiratory care personnel showed faulty infection control procedures (for example, the same multiple-dose bottle of albuterol was used for many mechanically ventilated patients). More case patients (39 [92.9%]) than controls (95 [70.4%]; P = 0.006) received nebulized albuterol, and case patients (67.5 treatments) received more treatments than controls (18 treatments; P < 0.001). In-use albuterol solutions had pH values that were unstable, and benzalkonium chloride concentrations declined over time to levels capable of supporting bacterial growth. Medication nebulizers and in-use bottles of albuterol harbored B. cepacia. Molecular fingerprints of patient isolates and environmental B. cepacia isolates were identical using repetitive-element PCR. No further isolates of B. cepacia were identified after institution of appropriate infection control procedures. CONCLUSIONS: Multiple-dose medications and reliance on benzalkonium chloride as a medication preservative provide a mechanism for nosocomial spread of microorganisms, particularly if infection control procedures are not carefully followed. Repetitive-element PCR is a useful fingerprinting technique for molecular epidemiologic studies of B. cepacia.
Asunto(s)
Burkholderia cepacia , Infección Hospitalaria/epidemiología , Nebulizadores y Vaporizadores , Infecciones por Pseudomonas/epidemiología , Respiración Artificial/efectos adversos , Infecciones del Sistema Respiratorio/epidemiología , Anciano , Albuterol/administración & dosificación , Burkholderia cepacia/aislamiento & purificación , Estudios de Casos y Controles , Brotes de Enfermedades , Contaminación de Medicamentos , Contaminación de Equipos , Humanos , Persona de Mediana Edad , Infecciones del Sistema Respiratorio/microbiología , Estudios RetrospectivosRESUMEN
Repetitive-element PCR (rep-PCR) with primers based on repetitive extragenic palindromic (REP) and enterobacterial repetitive intergenic consensus (ERIC) repeated DNA sequences was used for genomic finger-printing of Bartonella species. This technique was applied by using either extracted genomic DNA or preparations of whole bacterial cells directly. PCR fingerprints with either the REP-based primers (REP-PCR) or primers based on the ERIC repeat (ERIC-PCR) revealed species-specific band patterns for the various Bartonella isolates. DNA fingerprints obtained from rep-PCR of extracted genomic DNA or from preparations of whole cells yielded comparable patterns. ERIC-PCR banding patterns were less complex than those obtained by REP-PCR but allowed better discrimination between strains within species. By combining results of REP-PCR and ERIC-PCR, five different fingerprint profiles were identified among 17 isolates of Bartonella henselae, but only one profile was identified among the five isolates of Bartonella quintana. Other Bartonella species yielded distinct rep-PCR fingerprints. rep-PCR is a useful technique for identification of Bartonella organisms to the species level and offers the advantage of ease of performance, with only small quantities of cells needed for the whole-cell procedure. This technique also appears to be useful for subtyping B. henselae isolates.
Asunto(s)
Bartonella/genética , Dermatoglifia del ADN/métodos , Reacción en Cadena de la Polimerasa/métodos , Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Animales , Técnicas de Tipificación Bacteriana , Bartonella/clasificación , Bartonella/aislamiento & purificación , Infecciones por Bartonella/microbiología , Gatos , Secuencia de Consenso , Cartilla de ADN , ADN Bacteriano/genética , Estudios de Evaluación como Asunto , Humanos , Secuencias Repetitivas de Ácidos Nucleicos , Especificidad de la EspecieRESUMEN
In 1990, there was a significant increase in the number of lower respiratory tract infections and surgical wound infections in the adult intensive care units of our tertiary care teaching hospital caused by Acinetobacter baumannii compared with the number in 1989. During the 5-month period from April through August 1990, 84 isolates of A. baumannii were recovered from 50 hospitalized patients. Biotyping, comparison of antibiograms, plasmid analysis, and DNA polymorphisms of 20 isolates from 20 different patients, determined by the use of repetitive element PCR with primers aimed at repetitive extragenic palindromic sequences and enterobacterial repetitive intergenic consensus sequences, were used to investigate this apparent outbreak. Biotyping, antibiograms, plasmid analysis, and enterobacterial repetitive intergenic consensus PCR were not useful epidemiologically. Repetitive element PCR-mediated DNA fingerprinting using repetitive extragenic palindromic primers discriminated between epidemic and sporadic strains of A. baumannii and demonstrated four discrete clusters which were unique epidemiologically.