Showing papers by "Martin J. Blaser published in 1984"

A Review of Human Salmonellosis: II. Duration of Excretion Following Infection with Nontyphi Salmonella

Abstract: Convalescent excretion is a common sequel to salmonella infection, but in contrast to infections with Salmonella typhi, no clear picture of the natural history of nontyphi Salmonella excretion has emerged. The literature concerning frequency and site of chronic carriage, patterns of excretion, and relationship to bacteriologic methods used for enumeration of organisms was reviewed. An examination of 32 studies including 2,814 patients who were observed after salmonella infection showed that median duration of excretion was approximately five weeks. In univariant analyses, excretion was more prolonged in children less than five years of age, persons with symptomatic infections, persons infected with serotypes other than Salmonella typhimurium, and persons studied after first onset of symptoms. Persistent excretion beyond one year occurred in fewer than 1% of subjects. Despite the large number of convalescent excretors in the community at any one time, the paucity of outbreaks in which such food handlers or hospital personnel are implicated suggests that their role in transmission of salmonella infection is small. Because convalescent excretion is so common and persistent excretion and transmission so uncommon, follow-up fecal cultures after salmonella infections are rarely necessary.

Campylobacter jejuni outer membrane proteins are antigenic for humans.

Abstract: All Campylobacter jejuni strains have a major outer membrane protein (OMP) that migrates between a molecular weight of 41,000 (41K) and 45K and represents more than 50% of protein present, plus several more minor bands. Using 125I-radiolabeled C. jejuni cells in a radioimmunoprecipitation procedure to assess whether the OMPs were antigenic, we studied serum from rabbits immunized with C. jejuni cells, from humans convalescent after C. jejuni infection, and from appropriate controls. In this assay, the major OMP was the major antigen for both homologously and heterologously immunized rabbits and infected humans but not for controls. Minor bands at 29K and 50K were also antigenic. We tested human and animal sera in a Western blot procedure using anti-immunoglobulin A (IgA), anti-IgG, or anti-IgM conjugates. Homologous and heterologous immune rabbit serum, but not control serum, recognized a large number of membrane proteins between 15K and 91K, including the major OMP. Both Campylobacter spp.-infected and healthy humans showed IgA, IgG, and IgM responses to the major OMP, although the response was more pronounced in the former group. Sera from infected humans recognized several minor bands to a significantly greater extent than control sera did. Our data suggest that there is antigenic similarity between the OMPs of different C. jejuni strains and that some of these OMPs recognized by infected animals and humans have vaccinogenic potential. Images

Importance of host factors in human salmonellosis caused by multiresistant strains of Salmonella.

Abstract: Antimicrobial resistance patterns of Salmonella isolates from persons in randomly selected urban and rural counties in the United States were examined along with clinical and epidemiological characteristics of the host. Multiresistant strains, isolated from 66 (12.2%) of 542 persons evaluated, were associated with five of 20 variables in univariate analyses: serotype heidelberg, host of Hispanic origin, host exposure to penicillins within four weeks before stool culture, age greater than or equal to 60 years, and regular antacid use. By multiple linear regression, the first three variables were each significantly associated with infections due to multiresistant Salmonella. One or more of the last three variables, thought to be host factors that may promote disease, were present for persons yielding 38% of multiresistant strains but only 12% of sensitive strains (P less than .001). The relatively large proportion of multiresistant Salmonella among isolates from persons with these risk factors suggests that to cause disease, resistant organisms are more dependent than are sensitive organisms on host characteristics.

Killing of Fabric-Associated Bacteria in Hospital Laundry by Low-Temperature Washing

Abstract: Hospitals using 71.1 C water for laundering consume vast amounts of energy. We studied whether washing at 22 C would result in fabric-associated bacterial counts significantly different from those remaining after the high-temperature wash procedure in general use. Using a standard method to enumerate fabric-associated bacteria, we found that soiled sheets and terry cloth items were contaminated, respectively, with 10(6) and 10(8) cfu/100 cm2 of fabric area, predominantly gram-negative rods (especially Enterobacteriaceae and Pseudomonadaceae). Staphylococcus species were the most common gram-positive organisms. A standard low-temperature washing cycle without laundry chemicals removed 3 log10 of bacteria by agitation, dilution, and drainage. When low-temperature laundry chemicals were used, 3 log10 of bacteria were killed after the bleach was added, and sheets and terry cloth items had postwash colony counts of 10(1)-10(2) cfu/100 cm2. Drying removed an additional 1-2 log10 organisms. Bacterial counts and species from low- and high-temperature washed fabrics were comparable. Low-temperature washing is therefore as effective as high-temperature washing for eliminating pathogenic bacteria from hospital laundry.

Persistent Campylobacter jejuni Infection in an Immunocompromised Patient

Abstract: Recurrent bacteremia and enteritis due to a specific serotype of Campylobacter jejuni occurred over a 12-month period in a patient on hemodialysis with systemic lupus erythematosus who was also deficient in serum IgA and IgM. A bactericidal defect in the patient's sera for C. jejuni was shown. A role for immunoglobulins in the host response to C. jejuni is suggested, in that the IgA deficiency may have predisposed the patient to chronic gastrointestinal carriage and because the resolution of the bacteremia corresponded with the delayed appearance in the blood of IgG specific for the infecting strain.

Primary Meningococcal Pericarditis: A Disease of Adults Associated with Serogroup C Neisseria meningitidis

Abstract: Pericarditis due to Neisseria meningitidis is usually a consequence of meningeal disease or meningococcemia. This presentation includes a case report of primary meningococcal pericarditis (PMP) and a review of the clinical and epidemiologic features of 15 previously reported cases. All cases have been reported in the past 15 years. Most patients were older teenagers or adults. The median age and age distribution of PMP cases in the United States were significantly greater than that of patients with other meningococcal diseases reported to the Centers for Disease Control (CDC) (P = .005). Similarly, serogroup C N. meningitidis was isolated from 88% of U.S. patients with PMP, compared with isolation from 22% of patients with other meningococcal diseases reported to the CDC (P = .00016). Culture of pericardial fluid usually yielded meningococci, and most patients presented with signs and symptoms typical of purulent pericarditis. A positive pericardial culture was associated with the development of cardiac tamponade (P = .03). With appropriate antibiotic treatment and drainage of pericardial fluid when indicated, all 16 patients survived and experienced few or no sequelae.

Epidemiology of Campylobacter Infections

Abstract: Campylobacter jejuni or Campylobacter coli organisms may exist as commensals in the intestinal tracts of a wide variety of wild and domestic animals. Whether or not Campylobacters are pathogenic in their animal hosts. That some of the organisms associated with animals cause infection and disease in humans is known from data obtained in a few outbreaks in which an animal or animal product was ultimately identified as a source. The sources of Campylobacter organisms found in water are not known but may be due to fecal contamination by wild or domestic animals. Studies of mud from contaminated rivers in Southampton failed to show Campylobacters. However, isolations from both mud and sewage sludge have been made in the US Campylobacter enteritis has been reported in children and young adults who before their illnesses had close contact with infected puppies. Campylobacter enteritis is sometimes associated with bacteremia.

Epidemiologic Analysis of a Cluster of Homicides of Children in Atlanta

Abstract: Between July 1, 1979, and March 15, 1981, there were 22 unsolved homicides and two unsolved disappearances of Atlanta children. Using epidemiologic methods, we attempted to identify factors that had put children at an increased risk of homicide. That all victims in this cluster were black, killed away from home, and that asphyxiation was overrepresented suggests that the cluster was discrete. The cluster was not homogeneous in relation to location of the victim's area of residence or location of the body; however, the median distance of 9.3 miles from home to body suggests that in some cases a motor vehicle was involved. A neighborhood-based study of the male victims and age- and sex-matched controls showed that victims more often ran errands for money (relative risk, 7.9) and were more often alone on the streets or in shopping centers; therefore, they may have been more approachable than other children in the neighborhood. ( JAMA 1984;251:3255-3258)

Comparison of methods for recovery of Escherichia coli and Staphylococcus aureus from seeded laundry fabrics.

Abstract: To assess the effect of laundry procedures on fabric-associated bacteria, a standard method of enumeration is needed. We evaluated six methods for enumeration of Escherichia coli and Staphylococcus aureus seeded (10(2) and 10(5) CFU/100 cm2 of fabric area) onto sterilized hospital sheets and terry . Two methods involved maceration of seeded swatches in broth followed by passage of the broth through a 0.45-micron-pore-size, 47-mm-diameter filter membrane. Three methods involved agitation of seeded swatches in broth with a paint shaker and membrane filtration of the broth to recover eluted bacterial cells, and the final method involved direct enumeration of cells on fabrics by overlaying seeded swatches with agar containing triphenyltetrazolium chloride as an indicator. The most convenient recovery method employed a 90-s agitation followed by serial dilution of broths and membrane filtration. This method provided 44/57% (low seed/high seed) recovery of E. coli from sheets and 133/31% from terry and 34/74% recovery of S. aureus from sheets and 58/57% from terry . Although maceration provided similar recovery of E. coli and S. aureus, it is a less-practical method. The direct enumeration method was ineffective for enumerating gram-positive bacteria. We conclude that either the agitation or maceration method used enumerated the seeded bacteria to within 1 log10 of their expected number and can be used to assess the bactericidal effectiveness of various steps in the laundering process.