A novel family of intrinsic chloramphenicol acetyltransferase CATC in Vibrio parahaemolyticus: Naturally occurring variants reveal diverse resistance levels against chloramphenicol

2019 ◽  
Vol 54 (1) ◽  
pp. 75-79 ◽  
Author(s):  
Gang Zhang ◽  
Kaiwen Sun ◽  
Guomin Ai ◽  
Jianjuan Li ◽  
Na Tang ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Chloramphenicol Acetyltransferase ◽  
Naturally Occurring

scholarly journals Comparative Survival and the Cold-Induced Gene Expression of Pathogenic and Nonpathogenic Vibrio Parahaemolyticus from Tropical Eastern Oysters during Cold Storage

2020 ◽  
Vol 17 (6) ◽  
pp. 1836
Author(s):  
Francisco Alarcón Elvira ◽  
Violeta T. Pardío Sedas ◽  
David Martínez Herrera ◽  
Rodolfo Quintana Castro ◽  
Rosa María Oliart Ros ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Vibrio Parahaemolyticus ◽  
Cold Shock ◽  
Gene Expressions ◽  
Reverse Transcription Pcr ◽  
Naturally Occurring ◽  
Gene Response ◽  
Eastern Oysters ◽  
Kinetics Of

Expression of the regulatory stress rpoS gene controls the transcription of cspA genes, which are involved in survival and adaptation to low temperatures. The purpose of this study was to assess the growth kinetics of naturally occurring V. parahaemolyticus in shellstock oysters and in vitro and the cold-shock-induced expression of the rpoS and cspA gene response in vitro during postharvest refrigeration. Naturally contaminated eastern oysters (Crassostrea virginica) and pathogenic (Vp-tdh) and nonpathogenic (Vp-tlh) isolates were stored at 7 ± 1 °C for 168 h and 216 h, respectively. The regulatory stress (rpos) and cold-shock (cspA) gene expressions were determined by reverse transcription PCR. At 24 h, the (Vp-tdh) strain grew faster (p < 0.05) than the (Vp-tlh) strain in oysters (λ = 0.33, 0.39, respectively) and in vitro (λ = 0.89, 37.65, respectively), indicating a better adaptation to cold shock for the (Vp-tdh) strain in live oysters and in vitro. At 24 h, the (Vp-tdh) strain rpoS and cspA gene expressions were upregulated by 1.9 and 2.3-fold, respectively, but the (Vp-tlh) strain rpoS and cspA gene expressions were repressed and upregulated by −0.024 and 1.9-fold, respectively. The V. parahaemolyticus strains that were isolated from tropical oysters have adaptive expression changes to survive and grow at 7 °C, according to their virulence.

scholarly journals The use of naturally occurring hybrid variants of chloramphenicol acetyltransferase to investigate subunit contacts

1981 ◽  
Vol 193 (2) ◽  
pp. 541-552 ◽  
Author(s):  
L C Packman ◽  
W V Shaw
Keyword(s):  
Chloramphenicol Acetyltransferase ◽  
Alpha Subunit ◽  
Type I ◽  
Chloramphenicol Resistance ◽  
Type Iii ◽  
Naturally Occurring ◽  
Alpha Beta ◽  
Beta 2

1. Hybrids of the tetrameric enzyme chloramphenicol acetyltransferase (EC 2.3.1.28) were formed in vivo in a strain of Escherichia coli which harbours two different plasmids, each of which normally confers chloramphenicol resistance and specifies an easily distinguished enzyme variant (type I or type III) which is composed of identical subunits. Cell-free extracts of the dual-plasmid strain were found to contain five species of active enzyme, two of which were the homomeric enzymes corresponding to the naturally occurring tetramers of the type-I (beta 4) and type-III (alpha 4) enzymes. The other three variants were judged to be the heteromeric hybrid variants (alpha 3 beta, alpha 2 beta 2, alpha beta 3). 2. The alpha 3 beta and alpha 2 beta 2 hybrids of chloramphenicol acetyltransferase were purified to homogeneity by combining the techniques of affinity and ion-exchange chromatography. The alpha beta 3 variant was not recovered and may be unstable in vitro. 3. The unique lysine residues that could not be modified with methyl acetimidate in each of the native homomeric enzymes were also investigated in the heteromeric tetramers. 4. Lysine-136 remains buried in each beta subunit of the parental (type I) enzyme and in each of the hybrid tetramers. Lysine-38 of each alpha subunit is similarly unreactive in the native type-III chloramphenicol acetyltransferase (alpha 4), but in the alpha 2 beta 2 hybird lysine-38 of each alpha subunit is fully exposed to solvent. Another lysine residue, fully reactive in the alpha 4 enzyme, was observed to be inaccessible to modification in the symmetrical hybrid. The results obtained for the alpha 3 beta enzyme suggest that lysine-38 in two subunits and a different lysine group (that identified in the alpha 2 beta 2 enzyme) in the third alpha subunit are buried. 5. A tentative model for the subunit interactions of chloramphenicol acetyltransferase is proposed on the basis of the results described.

Effect of Ploidy on Vibrio parahaemolyticus and Vibrio vulnificus Levels in Cultured Oysters

2020 ◽  
Vol 83 (11) ◽  
pp. 2014-2017
Author(s):  
JESSICA L. JONES ◽  
KERI A. LYDON ◽  
WILLIAM C. WALTON
Keyword(s):  
Crassostrea Virginica ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Vibrio Vulnificus ◽  
High Quality ◽  
Colony Hybridization ◽  
Naturally Occurring ◽  
Rapid Growth Rate ◽  
Vibrio Spp ◽  
Half Sibling

ABSTRACT Vibrio parahaemolyticus and Vibrio vulnificus are naturally occurring human pathogenic bacteria commonly found in estuarine environments where oysters are cultured. The use of triploid oysters has increased due to their rapid growth rate and because they maintain a high quality throughout the year. Previous work suggested levels of Vibrio spp. may be lower in triploid oysters than diploid oysters. Therefore, this study aimed to determine whether there is a difference in the abundances of V. parahaemolyticus and V. vulnificus between half-sibling diploid and triploid American oysters (Crassostrea virginica). In four trials, 100 individual oysters (either iced or temperature abused) were analyzed for V. parahaemolyticus and V. vulnificus by using direct plating followed by colony hybridization. Mean levels of V. parahaemolyticus in iced and abused diploid oysters were 3.55 and 4.21 log CFU/g, respectively. Mean levels in iced and abused triploid oysters were 3.49 and 4.27 log CFU/g, respectively. Mean levels of V. vulnificus in iced and abused diploid oysters were 3.53 and 4.56 log CFU/g, respectively. Mean levels in iced and abused triploid oysters were 3.54 and 4.55 log CFU/g, respectively. The differences in Vibrio spp. abundances between diploid and triploid oysters was not significant (P &gt; 0.05). However, the differences across treatments were significant (P &lt; 0.05), with the exception of V. parahaemolyticus levels in trial 3 (P = 0.83). Variation between individual oysters was also observed, with 12 of 808 measurements being outside of the 95th percentile. This phenomenon of occasional statistical outliers (“hot” or “cold” oysters) has been previously described and supports the appropriateness of composite sampling to account for inherent animal variability. In summary, the data indicate that abundances of V. parahaemolyticus and V. vulnificus are not dependent on the ploidy of cultured oysters but vary with the type of handling. HIGHLIGHTS

Experimental pathogenicity of Vibrio parahaemolyticus for the schistosome-bearing snail Biomphalaria glabrata

1980 ◽  
Vol 26 (4) ◽  
pp. 503-506 ◽  
Author(s):  
Hugh W. Ducklow ◽  
Hector M. Tarraza Jr. ◽  
Ralph Mitchell
Keyword(s):  
Puerto Rican ◽  
Vibrio Parahaemolyticus ◽  
Trichloroacetic Acid ◽  
Sublethal Effects ◽  
Lethal Dose ◽  
Biomphalaria Glabrata ◽  
Wild Populations ◽  
Naturally Occurring ◽  
Experimental Pathogenicity ◽  
Significant Mortality

The bacterium Vibrio parahaemolyticus was found to be pathogenic for the schistosome intermediate host Biomphalaria glabrata (Say). When administered topically, a nonenteritis- associated strain of the bacterium had an LD50 (median lethal dose) of 6.8 × 107 cells per snail. A 5% trichloroacetic acid (TCA) extract from V. parahaemolyticus was found to kill B. glabrata. Sublethal effects of V. parahaemolyticus include shell deterioration and increased heart rate. Both albino aquarium populations and naturally occurring Puerto Rican wild populations of B. glabrata are susceptible to V. parahaemolyticus. This bacterium provides a useful model for the study of pathogens and biological control of schistosome vector snails, since it causes significant mortality and is recognized as a pathogen of other invertebrates.

Populations of Vibrio parahaemolyticus in Retail Oysters from Florida Using Two Methods

2001 ◽  
Vol 64 (5) ◽  
pp. 682-686 ◽  
Author(s):  
ROBIN K. ELLISON ◽  
ERIKA MALNATI ◽  
ANGELO DePAOLA ◽  
JOHN BOWERS ◽  
GARY E. RODRICK
Keyword(s):  
Alkaline Phosphatase ◽  
Vibrio Parahaemolyticus ◽  
Geometric Mean ◽  
Environmental Distribution ◽  
Direct Plating ◽  
Naturally Occurring ◽  
Biochemical Identification ◽  
Stressed Cells ◽  
Species Specific ◽  
Identification Techniques

Vibrio parahaemolyticusis a naturally occurring estuarine bacterium that is often associated with gastroenteritisin humans following consumption of raw molluscan shellfish. A number of studies have investigated the environmental distribution of V. parahaemolyticus, but little is known about the levels of this organism during distribution of oysters or at the point of consumption. Duplicate samples of shellstock oysters were collected monthly (September 1997 to May 1998) from the same four restaurants and three wholesale seafood markets in the Gainesville, Fla. area and analyzed for total V. parahaemolyticus densities using two methods: a standard MPN method (BAM-MPN) and a new direct plating procedure (direct-VPAP). Both methods employed an alkaline phosphatase-labeled DNA probe (VPAP) targeting the species-specific thermolabile hemolysin (tlh) gene to confirm suspect colonies as V. parahaemolyticus. The highest monthly geometric mean V. parahaemolyticus density was observed in October of 1997 (~3,000/g) with similarly high values during September and November of 1997. From December 1997 to May 1998 mean densities were generally less than 100/g, falling to ~10/g in February and March. A strong correlation (r = 0.78) between the direct-VPAP and BAM-MPN methods for determining V. parahaemolyticus densities in market-level oysters was observed. The direct-VPAP method was more rapid and precise while the BAM-MPN was more sensitive and may better recover stressed cells. The utilization of the VPAP probe for identification of V. parahaemolyticus sharply reduced the labor for either method compared to biochemical identification techniques used in earlier V. parahaemolyticus surveys.

Growth and Survival of Vibrio parahaemolyticus in Postharvest American Oysters

2002 ◽  
Vol 65 (6) ◽  
pp. 970-974 ◽  
Author(s):  
J. A. GOOCH ◽  
A. DePAOLA ◽  
J. BOWERS ◽  
D. L. MARSHALL
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Geometric Mean ◽  
Fold Increase ◽  
Mobile Bay ◽  
Postharvest Storage ◽  
Growth And Survival ◽  
Naturally Occurring ◽  
Hemolysin Gene ◽  
Plating Method ◽  
Species Specific

Oysters at the retail stage of distribution generally contain greater densities of Vibrio parahaemolyticus than do oysters at harvest. The objective of this study was to determine the effects of postharvest storage at 26 and 3°C on the growth and survival of naturally occurring V. parahaemolyticus in shellstock American oysters (Crassostrea virginica). Oysters were collected monthly from May 1998 through April 1999 from Mobile Bay, Alabama, and their V. parahaemolyticus densities were determined after 0, 5, 10, and 24 h of postharvest storage at 26°C. After 24 h of storage at 26°C, oysters were transferred to a refrigerator at 3°C and analyzed 14 to 17 days later. V. parahaemolyticus numbers were determined by a direct plating method involving an alkaline-phosphatase-labeled DNA probe that targets the species-specific thermolabile hemolysin gene (tlh-AP) to identify suspect isolates. From April to December, when water temperatures at harvest were &gt;20°C, the geometric mean harvest density of V. parahaemolyticus was 130 CFU/g. When water temperatures were &lt;20°C, the geometric mean harvest density was 15 CFU/g. After harvest, V. parahaemolyticus multiplied rapidly in live oysters held at 26°C, showing a 50-fold increase (1.7 log CFU/g) at 10 h and a 790-fold increase (2.9 log CFU/g) at 24 h (April through December). Average V. parahaemolyticus numbers showed a sixfold decrease (0.8 log CFU/g) after approximately 14 days of refrigeration. These results indicate that V. parahaemolyticus can grow rapidly in unrefrigerated oysters.

Sensitivity of Vibrio Species in Phosphate-Buffered Saline and in Oysters to High-Pressure Processing

2003 ◽  
Vol 66 (12) ◽  
pp. 2276-2282 ◽  
Author(s):  
DAVID W. COOK
Keyword(s):  
High Pressure ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
High Pressure Processing ◽  
Decimal Reduction Time ◽  
Log Reduction ◽  
Naturally Occurring ◽  
Multiple Strains ◽  
Phosphate Buffered Saline ◽  
Vibrio Spp

Multiple strains of Vibrio vulnificus, Vibrio parahaemolyticus, and Vibrio cholerae non-O1 were tested in phosphate-buffered saline for their sensitivity to high-pressure processing (HPP). Variability in sensitivity among strains was observed for all species; this variability decreased at higher pressures. V. vulnificus was the species that was most sensitive to treatment at 200 MPa (decimal reduction time [D] = 26 s), and V. cholerae was the species that was most resistant to treatment at 200 MPa (D = 149 s). The O3:K6 serotype of V. parahaemolyticus was more resistant to pressure than other serotypes of V. parahaemolyticus were. The results of studies involving V. vulnificus naturally occurring in oysters revealed that a pressure treatment of 250 MPa for 120 s achieved a &gt;5-log reduction in the levels of this bacterium. V. parahaemolyticus serotype O3:K6 in oysters required a pressure of 300 MPa for 180 s for a comparable 5-log reduction. When properly applied, HPP can be effective in improving the safety of shellfish with respect to Vibrio spp.

scholarly journals Infaunal Burrows Are Enrichment Zones for Vibrio parahaemolyticus

2011 ◽  
Vol 77 (11) ◽  
pp. 3703-3714 ◽  
Author(s):  
Megan D. Gamble ◽  
Charles R. Lovell
Keyword(s):  
Pore Water ◽  
Vibrio Parahaemolyticus ◽  
Fiddler Crab ◽  
Carbon Substrate ◽  
Uca Pugilator ◽  
Content Type ◽  
The North ◽  
Physiological Diversity ◽  
Naturally Occurring ◽  
Creek Water

ABSTRACTVibrio parahaemolyticus, a species that includes strains known to be pathogenic in humans, and otherVibrionaceaeare common, naturally occurring bacteria in coastal environments. Understanding the ecology and transport of these organisms within estuarine systems is fundamental to predicting outbreaks of pathogenic strains. Infaunal burrows serve as conduits for increased transport of tidal waters andV. parahaemolyticuscells by providing large open channels from the sediment to salt marsh tidal creeks. An extensive seasonal study was conducted at the North Inlet Estuary in Georgetown, SC, to quantifyVibrionaceaeand specificallyV. parahaemolyticusbacteria in tidal water, fiddler crab (Uca pugilator,Uca pugnax) burrow water, and interstitial pore water. Numbers ofV. parahaemolyticusbacteria were significantly higher within burrow waters (4,875 CFU ml−1) than in creek water (193 CFU ml−1) and interstitial pore water (128 CFU ml−1), demonstrating that infaunal burrows are sites ofV. parahaemolyticusenrichment. A strong seasonal trend of increased abundances ofVibrionaceaeandV. parahaemolyticusorganisms during the warmer months of May through September was observed. Multilocus sequence typing (MLST) analysis of isolates presumed to beV. parahaemolyticusfrom creek water, pore water, and burrow water identified substantial strain-level genetic variability amongV. parahaemolyticusbacteria. Analysis of carbon substrate utilization capabilities of organisms presumed to beV. parahaemolyticusalso indicated physiological diversity within this clade, which helps to explain the broad distribution of these strains within the estuary. These burrows are “hot spots” ofVibrionaceaeandV. parahaemolyticuscell numbers and strain diversity and represent an important microhabitat.

Pathology of Bone Cells in Pigs with Experimental Turbinate Osteoporosis (Atrophic Rhinitis)

1971 ◽  
Vol 29 ◽  
pp. 304-305
Author(s):  
A. W. Fetter ◽  
C. C. Capen
Keyword(s):  
Mucous Membrane ◽  
Bone Cells ◽  
Atrophic Rhinitis ◽  
Infectious Agents ◽  
Metabolic Disturbances ◽  
Progressive Reduction ◽  
Naturally Occurring ◽  
Fundamental Cause ◽  
Osteocytic Osteolysis ◽  
Uncertain Etiology

Atrophic rhinitis in swine is a disease of uncertain etiology in which infectious agents, hereditary predisposition, and metabolic disturbances have been reported to be of primary etiologic importance. It shares many similarities, both clinically and pathologically, with ozena in man. The disease is characterized by deformity and reduction in volume of the nasal turbinates. The fundamental cause for the localized lesion of bone in the nasal turbinates has not been established. Reduced osteogenesis, increased resorption related to inflammation of the nasal mucous membrane, and excessive resorption due to osteocytic osteolysis stimulated by hyperparathyroidism have been suggested as possible pathogenetic mechanisms.The objectives of this investigation were to evaluate ultrastructurally bone cells in the nasal turbinates of pigs with experimentally induced atrophic rhinitis, and to compare these findings to those in control pigs of the same age and pigs with the naturally occurring disease, in order to define the fundamental lesion responsible for the progressive reduction in volume of the osseous core.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

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