Biomedical subjects

C Abeyta

Publications and source records attributed to C Abeyta.

9 recordsLinked to original sources

PubMed1997

Comparative sensitivity of 13 species of pathogenic bacteria to seven chemical germicides.

BACKGROUND: The relative resistance of diverse human bacterial pathogens to commonly used germicidal agents has not been established. METHODS: We measured by titration the survival of thirteen different bacteria after exposure to glutaraldehyde, formaldehyde, hydrogen peroxide, peracetic acid, cupric ascorbate, sodium hypochlorite, or phenol. RESULTS: Our comparative experiments allowed classification of the organisms' survival into four groups: (a) Pseudomonas aeruginosa and Staphylococcus aureus showed the most resistance, (b) Clostridium perfringens, Salmonella typhimurium, Staphylococcus epidermidis, and Escherichia coli O157:H7 showed intermediate resistance, (c) Listeria monocytogenes, Shigella sonnei, and Vibrio parahaemolyticus survived some treatments with chemical agents only in the presence of protecting protein (serum albumin), and (d) Vibrio cholerae, Vibrio vulnificus, Bacillus cereus, and Yersinia enterocolitica did not survive any of the treatments applied. CONCLUSION: We found species that more frequently survived exposure to germicidal agents were also those most commonly reported in association with hospital infections. Our findings suggest that resistance to disinfectants may be more important than pathogenicity in determining the relative prominence of an organism as an agent responsible for nosocomial infections.

Bacteria↗

PubMed1994

Urea hydrolysis can predict the potential pathogenicity of Vibrio parahaemolyticus strains isolated in the Pacific Northwest.

The ability of some strains of Vibrio parahaemolyticus to hydrolyze urea (uh+) can be used as a marker to predict which strains isolated from molluscan shellfish harvested in the Pacific Northwest are potentially pathogenic. The thermostable direct hemolysin-producing (TDH+) characteristic is a marker that is correlated with potential pathogenicity, and all of the TDH+ strains that we have isolated have been found to be uh+. Most of the uh+ strains belong to somatic antigen groups O3, O4 and O5. TDH+ strains are usually members of groups O4 and O5. The strains most often associated with human illness are members of the uh+, O4 group. The test for urease production is a simple screening test that can be helpful in predicting which strains are potentially pathogenic.

Animals↗

PubMed1990

Incidence of urea-hydrolyzing Vibrio parahaemolyticus in Willapa Bay, Washington.

A high incidence (71.5%) of Vibrio parahaemolyticus was found in samples of water, oysters, and sediment from a Washington State estuary which produces a significant amount of commercial product. Strains of V. parahaemolyticus capable of hydrolyzing urea comprised 58.4% of all V. parahaemolyticus isolates tested. Values for fecal coliforms were within certification criteria for commercial harvest and were not correlated with levels of V. parahaemolyticus.

Animals↗

PubMed1990

Listeria species in a California coast estuarine environment.

Listeria species and L. monocytogenes were found in 81 and 62%, respectively, of fresh or low-salinity waters (37 samples) in tributaries draining into Humboldt-Arcata Bay, Calif., during a winter (January-February) sampling period. The incidence of Listeria species and L. monocytogenes in sediment (46 samples) from the same sites where water was sampled was 30.4 and 17.4%, respectively. One of three bay water samples contained Listeria species (including L. monocytogenes), while of 35 samples of oysters examined, only 1 was found positive for Listeria species (L. innocua). A given species or L. monocytogenes serogroup appeared to predominate in fresh water when domesticated animals (cows, horses) were nearby, whereas greater variety with no species predominance was observed in areas with no direct animal influence.

Animals↗

PubMed1987

Incidence of Vibrio cholerae from estuaries of the United States West Coast.

The incidence of Vibrio cholerae in shellfish, sediment, and waters of California, Oregon, and Washington was determined during the summer of 1984. Samples from 24 distinct estuaries were analyzed qualitatively. V. cholerae non-O1 was found in 23 estuaries and in 44.6% of the 529 samples examined. V. cholerae O1 Inaba was isolated from water samples in Morro Bay, Calif. Vibrio mimicus was found in 2.3% of the samples. Cholera enterotoxin was not found in cell-free filtrates of the 100 isolates tested in the Y-1 mouse adrenal cell assay, but heat-labile cytotoxic activity was observed with 3% of the isolates.

Animals↗

PubMed1987

Virulent strains of Vibrio vulnificus isolated from estuaries of the United States West Coast.

Vibrio vulnificus was isolated from United States West Coast estuaries at a low frequency (5.9%) from 529 samples of water, shellfish, and sediment. Four strains tested with iron-treated mice had 50% lethal dose values ranging from 7.6 to 360 CFU, compared with a 50% lethal dose of 4.9 CFU for a clinical isolate that caused the death of a septicemic patient. The presence of this pathogen may be a hazard to users of marine beaches and consumers of raw shellfish on the West Coast, especially to persons most susceptible to V. vulnificus septicemia. Species-specific antiflagellar serum and a gene probe for cytotoxin-hemolysin production were useful for screening these environmental isolates.

Animals↗

PubMed1983

Comparison of iron milk and official AOAC methods for enumeration of Clostridium perfringens from fresh seafoods.

Fresh seafoods collected from Seattle area markets were evaluated for the presence and numbers of Clostridium perfringens. In a comparison of the official AOAC Shahidi-Ferguson perfringens and the simple iron milk methods, 29 of 287 samples of fresh fish and shellfish were positive for C. perfringens. All 29 positive samples were detected by the iron milk medium; however, only 7 of the 29 were detected by the AOAC methods. A statistical evaluation of the data showed a significant difference between the 2 methods.

Animals↗

PubMedDate not supplied

Enhancement of virulence of two environmental strains of Vibrio vulnificus after passage through mice.

The virulence of two environmental strains of Vibrio vulnificus to iron-loaded adult mice was enhanced by passage through mice. Estimates of 50% lethal dose values (LD50) determined by end point titration were reduced 100- and 1000-fold for the two strains. Passage through mice also selected for the opaque colony type phase variation of V. vulnificus, reported by others to be more virulent to mice than a translucent colony type.

Animals↗

PubMedDate not supplied

Iron milk medium method for recovering Clostridium perfringens from shellfish: collaborative study.

Eleven laboratories participated in a collaborative study analyzing shellfish (oysters, Crassostrea gigas) for the detection and enumeration of Clostridium perfringens by the iron milk medium (IMM) method. The IMM method was compared to AOAC Official Method 976.30. Shellfish were artificially inoculated with C. perfringens cells (vegetative and spores) at low (1 x 10(3) colony forming units [cfu]/g), medium (1 x 10(4) cfu/g), and high (1 x 10(6) cfu/g) levels. Negative controls (zero level) were analyzed by each laboratory. C. perfringens FD-1, the strain involved in a foodborne illness, was used. Blind duplicates of each inoculum level were analyzed, giving a total of 16 samples per laboratory. The selectivity of IMM relies solely on the rapid growth of C. perfringens at 45 degrees C indicated by stormy fermentation reaction within 18 h. C. perfringens is detected and enumerated using the most probable number technique. A statistical evaluation of the data found no significant differences between the estimates from the 2 methods. The IMM method for detection of C. perfringens from shellfish has been adopted first action by AOAC INTERNATIONAL.

Animals↗