Showing papers by "Martin J. Blaser published in 1982"

A Review of Human Salmonellosis: I. Infective Dose

Abstract: The notion that large inocula of salmonellae are necessary to induce illness in humans is based on the results of studies involving volunteers. However, investigations of outbreaks of salmonellosis suggest that the infective dose was often low. This incongruity was investigated by an examination of factors that could affect the infective dose of Salmonella, a review of nine studies in which salmonellae were administered to volunteers, and a review of 11 outbreaks of salmonellosis for which the infective doses could be calculated. Determination of the minimal infective doses from studies involving volunteers is limited by the strains used for testing, repeated testing of the same subjects, and the use of too few volunteers at the lower dose levels. In six of the 11 outbreaks, the actual doses ingested were calculated to be less than 10(3) organisms; the outbreaks with higher doses involved very high rates of attack and short periods of incubation. Data presented on median incubation periods during 12 typhoid outbreaks suggest that low doses were involved.

30 years of campylobacters: biochemical characteristics and a biotyping proposal for Campylobacter jejuni.

Abstract: Several biochemical test systems were studied for their potential usefulness for the examination of strains of Campylobacter species. Most (81%) of the C. jejuni strains hydrolyzed sodium hippurate, but strains of C. fetus, C. sputorum, and C. fecalis did not. Some (46%) of the C. jejuni strains and all of the C. sputorum subsp. sputorum, C. sputorum subsp. bubulus, and C. fecalis strains hydrolyzed DNA, but the C. fetus and C. sputorum subsp. mucosalis strains did not. Strains of all species of Campylobacter grew on charcoal-yeast extract agar, but 47% of the C. jejuni strains did not. Alkaline phosphatase activity was recorded for some strains of C. jejuni, but all other species were negative for this activity. Aryl sulfatase activity was detected in 7% of the C. jejuni, 15% of the C. fetus subsp. fetus, and all of the C. sputorum subsp. sputorum, C. sputorum subsp. bubulus, and C. fecalis strains, but it was not detected in the C. fetus subsp. venerealis and C. sputorum subsp. mucosalis strains. Most (93%) of the C. jejuni but none of the other Campylobacter strains contained lactobacillic acid when examined for cellular fatty acids. On the basis of results from three of these tests (hippurate hydrolysis, DNA hydrolysis, and growth on charcoal-yeast extract agar), clinical strains of C. jejuni were placed in eight biotypes.

Campylobacter enteritis associated with foodborne transmission

Abstract: During an outbreak of gastrointestinal illness at a boys summer camp in Connecticut in June-July 1980, Campylobacter jejuni was isolated from 16 of 41 ill persons but from none of 63 controls (P less than 0.001). When the indirect fluorescent antibody assay was used, cross-titering serum and isolates from five patients showed all isolates to be identical. Lack of serologic response in culture-negative ill persons suggested that a second etiologic agent may have been involved. Ten convalescent carriers treated with erythromycin had clearance of Campylobacter from their stools within 72 hours. Among 26 camp staff members affected, two clusters of illness were seen, each one week after a birthday party, one party on June 26 and the other on July 2. Eating cake at the parties was significantly associated with illness (p = 0.0002 and p = 0.019, respectively). Eating an edge or corner piece with more icing at one party was associated with illness (p = 0.024). The source of the contamination of the icing was not found. None of 15 ill campers had eaten birthday cake. Although rates of eating salad were not significantly different when ill campers were matched with healthy campers, the relative risk associated with eating salad was 5. Campylobacter was isolated from the hands of an infected staff member who, while ill, prepared salad for the campers.

Campylobacter enteritis in Denver.

Abstract: To determine the relative importance of Campylobacter jejuni as a cause of diarrheal illness in patients coming to three hospitals in Denver, we cultured stool specimens from 2,670 patients over a two-year period. C jejuni was identified in the feces of 124 patients (4.6 percent), Salmonella from 90 (3.4 percent) and Shigella from 77 (2.9 percent). Most Campylobacter isolates were obtained in the summer months and from patients 10 to 29 years old. The illness usually lasted less than two weeks; predominant symptoms were diarrhea (98 percent), abdominal pain (88 percent) and fever (82 percent); patients with severe illness frequently had objective evidence of nonspecific colitis. Occult blood and leukocytes were present in stool specimens of 71 percent and 85 percent, respectively, of the patients tested. The duration and severity of illness led to antibiotic therapy in about half of the patients; erythromycin appeared effective. This study confirms the importance of C jejuni as a cause of enteritis; this microorganism should be sought routinely in fecal specimens from patients with diarrhea.

Comparison of atmospheres of incubation for primary isolation of Campylobacter fetus subsp. jejuni from animal specimens: 5% oxygen versus candle jar.

Abstract: An atmosphere with reduced oxygen tension is required for the primary isolation of Campylobacter fetus subsp. jejuni. Therefore, we compared use of the conventional atmosphere of 5% oxygen and 8% carbon dioxide with use of a candle jar (17% oxygen and 3% carbon dioxide) for primary isolation of C. fetus subsp. jejuni from 263 positive canine, cattle, and turkey fecal or cecal specimens. At an incubation temperature of 42 degrees C, the atmosphere with 5% oxygen resulted in more Campylobacter colonies per plate (P less than 0.005) and consistently larger Campylobacter colonies (P less than 0.005) than did the candle jar, whereas the growth of interfering flora was similar. Overall, 96% of the 263 specimens were positive for C. fetus subsp. jejuni with 5% oxygen, and 90% were positive with the candle jar (P less than 0.02). More striking differences in isolation rates were seen when both the temperature and the atmosphere were varied: 5% oxygen at 42 degrees C enabled recovery of 93% of the isolates from 70 positive specimens, versus 46% recovery with the candle jar at 37 degrees C. Results with 5% oxygen at 37 degrees C were intermediate. The addition of FBP supplement (0.25% each of ferrous sulfate, sodium metabisulfite, and sodium pyruvate) to Campy-BAP selective medium made no improvement over unsupplemented medium at 42 degrees C (whether in 5% oxygen or in the candle jar), but there was significant improvement over unsupplemented medium when both media were incubated at 37 degrees in the candle jar.

Diversity of Serotypes in Outbreaks of Enteritis Due to Campylobacter jejuni

Abstract: 2/New Mexico/1979 41 1 1 Raw milk Isolate of the same serotype from cow feces supports milkborne transmission 3/Minnesota/1981 26 8 23/36 Raw milk Point-source exposure 4/Colorado/1981 2 2 1 Raw milk Asymptomatic excretors 5/Vermont/1978 3,000 2 13/16 Water Serologic responses of infected persons also 2 23/36 indicated that two epidemic strains were present 6/Connecticut/1980 1,300 1 4 Water Outbreak occurred over two-month period 1 4/21 1 22

Campylobacter Enteritis Associated With a Healthy Cat

Abstract: IN THE short time since Campylobacter jejuni has become recognized as a significant enteric pathogen of humans, information on the epidemiology of infection has been increasing rapidly. 1 Although direct contact with infected animals or consumption of contaminated water or foods of animal origin are generally suspected as being the important modes of transmission, in only the minority of cases can this be documented. Recent work has implicated contact with infected household pets as one avenue of transmission. 2-4 The pets involved in such cases were puppies and kittens with diarrhea who were shedding C jejuni . We now report a case of Campylobacter enteritis that occurred in association with infection in an apparently healthy adult cat. Report of a Case On Oct 15, 1980, nausea, vomiting, and severe abdominal cramps developed in a 23-year-old woman, and she began having up to five bloody bowel movements per day. On Oct 19,

Salmonellosis at rural and urban clinics in bangladesh epidemiologic and clinical characteristics

Abstract: The authors studied the frequency of diarrheal illness associated with non-typhi Salmonella at two clinics in Bangladesh for the years 1977-1979. Non-typhi salmonellae were isolated from 0.29% of fecal specimens or rectal swabs in an urban area and 0.26% of similar specimens in a rural area; the frequency of isolations peaked in the summer months. Isolations of Shigella and Vibrio cholerae were much more common than Salmonella. Only two of 50 Salmonella isolates were resistant to more than one antibiotic. None of 13 isolates tested produced an enterotoxin. S. java and S. virchow accounted for 64% of all the isolates. Patients with diarrheal illness associated with isolation of Salmonella frequency had vomiting (88%), watery diarrhea (78%), abdominal pain (61%), and fever (39%), but the clinical features of the illnesses and the socioeconomic backgrounds of the patients could not be distinguished from those of matched controls who were attending the same clinic. The infrequency of Salmonella infection in an area where several other bacterial and viral enteric diseases are hyperendemic requires further investigation.

Campylobacter Enteritis Presenting with Convulsions

Abstract: A 14-month old boy presented to the hospital having had a convulsion. Initial work-up was essentially negative except for the presence of a temperature of 40 C. On the second hospital day, the patient began to have diarrhea and Campylobacter jejuni was isolated. This case illustrates that Campylobacter infection may be associated with febrile convulsions, and that these may precede the diarrheal phase of the illness.

Comparison of CampyPak II with standard 5% oxygen and candle jars for growth of Campylobacter jejuni from human feces.

Abstract: To determine optimal temperature and atmospheric conditions for isolating Campylobacter jejuni from fecal specimens of humans, we studied six laboratory isolates and 19 fecal specimens that were known to contain C. jejuni. We compared incubations in 5% oxygen, the CampyPak II (BBL Microbiology Systems, Cockeysville, Md.) with 6 plates per jar (CP-6) and 12 plates per jar (CP-12), and candle jars at 37 and 42 degrees C. At both temperatures, the colony sizes for the laboratory strains were larger in the 5% O2 and the CP-6 than under the other two conditions. For the primary isolations, CP-12 failed to detect one and two campylobacters at 42 and 37 degrees C, respectively, whereas the candle jar failed to detect one at 42 degrees C and four at 37 degrees C. Colony size was again larger in the 5% O2 and the CP-6. For all four atmospheric conditions tested, colonies were significantly larger at 42 degrees C than at 37 degrees C. These studies showed that incubation at 42 degrees C in either 5% O2 or the CampyPak II with six plates per jar was optimal for primary isolation of C. jejuni from fecal specimens of humans. The candle jars incubated at 42 degrees C appeared to be satisfactory for primary isolation of C. jejuni from human feces, but incubation at 37 degrees C was not acceptable.