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1.
J Dairy Sci ; 107(3): 1460-1471, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37944802

ABSTRACT

The objective of this study was to evaluate the effects of partially replacing soybean meal (SBM) with algal sources on in vitro ruminal fermentation. Using 6 fermenters in a 3 × 3 replicated Latin square with 3 periods of 10 d each, we tested 3 treatments: a control diet (CRT) with SBM at 17.8% of the diet dry matter (DM); and 50% SBM biomass replacement with either Chlorella pyrenoidosa (CHL); or Spirulina platensis (SPI). The basal diet was formulated to meet the requirements of a 680-kg Holstein dairy cow producing 45 kg/d of milk with 3.5% fat and 3% protein. All diets had a similar nutritional composition (16.0% CP; 34.9% NDF; 31.0% starch, DM basis) and fermenters were provided with 106 g DM/d split into 2 portions. After 7 d of adaptation, samples were collected for 3 d of each period for analyses of ruminal fermentation at 0, 1, 2, 4, 6, and 8 h after morning feeding for evaluation of the ruminal fermentation kinetics. For the evaluation of the daily production of total metabolites and for the evaluation of nutrient degradability, samples from the effluent containers were collected daily. Statistical analysis was performed with the MIXED procedure of SAS with treatment, time, and their interactions considered as fixed effects; day, square, and fermenter were considered as random effects. Orthogonal contrasts (CRT vs. algae; and CHL vs. SPI) were used to depict the treatment effect, and significance was declared when P ≤ 0.05. Fermenters that received algae-based diets had a greater propionate molar concentration and molar proportion when compared with the fermenters fed CRT diets. In addition, those algae-fed fermenters had lower branched short-chain fatty acids (BSCFA) and isoacids (IA), which are biomarkers of ruminal protein degradation, along with lower ammonia (NH3-N) concentration and greater nonammonia nitrogen (NAN). When contrasting with fermenters fed SPI-diets, fermenters fed based CHL-diets had a lower molar concentration of BSCFA and IA, along with lower NH3-N concentration and flow, and greater NAN, bacterial nitrogen flow, and efficiency of nitrogen utilization. Those results indicate that CHL protein may be more resistant to ruminal degradation, which would increase efficiency of nitrogen utilization. In summary, partially replacing SBM with algae biomass, especially with CHL, is a promising strategy to improve the efficiency of nitrogen utilization, due to the fact that fermenters fed CHL-based diets resulted in a reduction in BSCFA and IA, which are markers of protein degradation, and it would improve the efficiency of nitrogen utilization. However, further validation using in vivo models are required.


Subject(s)
Chlorella , Microalgae , Female , Cattle , Animals , Fermentation , Lactation , Proteolysis , Animal Feed/analysis , Biomass , Chlorella/metabolism , Flour/analysis , Glycine max , Nutrients/analysis , Nitrogen/metabolism
2.
Environ Monit Assess ; 190(6): 320, 2018 May 02.
Article in English | MEDLINE | ID: mdl-29717352

ABSTRACT

The presence of micropollutants that include endocrine-disrupting compounds (EDC) in aquatic environments is currently one of the most relevant aspects of water quality due to their adverse effects on aquatic organisms and human health. From the several categories of EDC, 17ß-estradiol (E2) is a natural hormone, which is prevalent in vertebrates, associated with the female reproductive system and maintenance of the sexual characters. 17α-Ethinylestradiol (EE2) is a synthetic hormone produced from the natural hormone E2 and is an essential component of oral contraceptives. These compounds are susceptible to bioconcentration and have high potential to bioaccumulation. Wastewater treatment plants are the main point source of E2 and EE2 into aquatic environments, but conventional wastewater treatment systems are not specifically designed for steroid removal. To overcome this problem, biological tertiary treatment may be a solution for the removal of emergent pollutants such as E2 and EE2. The main purpose of the present study is to provide a solution based on the optimization of a rotating biological contactor system to remove estrogens, specifically E2 and EE2, and to quantify their removal efficiency on different matrices, namely real wastewater and different synthetic wastewaters. All assays presented viable removal efficiencies for compound E2 with values always above 50%; real wastewater yielded the highest removal efficiencies. EE2 removal had better removal efficiencies with synthetic wastewater as feed solution, with removals above 15%, whereas the removal efficiency with real wastewater was inexistent.


Subject(s)
Estradiol/analysis , Ethinyl Estradiol/analysis , Waste Disposal, Fluid/methods , Wastewater/chemistry , Water Pollutants, Chemical/analysis , Endocrine Disruptors/analysis , Environmental Monitoring , Estrogens/analysis , Humans
3.
Arq. bras. med. vet. zootec. (Online) ; 70(6): 1699-1702, nov.-dez. 2018. ilus
Article in English | LILACS, VETINDEX | ID: biblio-969636

ABSTRACT

Canine Leproid Granuloma Syndrome (CLGS), also known as canine leprosy, is a cutaneous nodular infectious disease caused by Mycobacterium sp.. Despite being reported worldwide, it is still quite unknown and underdiagnosed. Diagnosis may be achieved by cytopathology or histopathology of skin lesions, but identification of the infectious agent is complex, since bacterial in vitro growth is not possible, relying upon molecular techniques such as PCR to confirm Mycobacterium DNA in the sample. We report a CLGS case in Niteroi, Rio de Janeiro state, Brazil, diagnosed by cytopathology and submitted to molecular identification of the agent. PCR amplification of hsp65 gene was performed and revealed 100% genetic homology to M. murphy strain. This is the first CLGS report with molecular identification in Rio de Janeiro state, and this finding should raise awareness about CLGS as a differential diagnosis among granulomatous skin diseases in this region.(AU)


A síndrome de granuloma leproide canino (SGLC), também conhecida como lepra canina, é uma doença infecciosa cutânea nodular causada por Mycobacterium sp. Apesar de ser relatada mundialmente, ainda é bastante desconhecida e subdiagnosticada. O diagnóstico pode ser conseguido por citopatologia ou histopatologia de lesões cutâneas, mas a identificação do agente infeccioso é complexa, uma vez que o crescimento in vitro bacteriano não é possível, dependendo de técnicas moleculares como a PCR para confirmar o DNA de Mycobacterium na amostra. Relatou-se um caso da SGLC em Niterói, estado do Rio de Janeiro, Brasil, diagnosticado por citopatologia e submetido à identificação molecular do agente. Foi realizada amplificação por PCR do gene hsp65, que revelou 100% de homologia genética com a cepa M. murphy. Este é o primeiro relato da SGLC com identificação molecular no estado do Rio de Janeiro, o que mostra a importância de se acrescentar a SGLC ao diagnóstico diferencial das doenças granulomatosas de pele nessa região.(AU)


Subject(s)
Animals , Dogs , Polymerase Chain Reaction/statistics & numerical data , Mycobacterium/cytology , Mycobacterium/pathogenicity , Mycobacterium Infections , Dogs
4.
J Helminthol ; 89(1): 19-27, 2015 Jan.
Article in English | MEDLINE | ID: mdl-26262593

ABSTRACT

Pontoporia blainvillei (Gervais and d'Orbigny, 1844) is an endangered small cetacean endemic to South America with four Franciscana Management Areas (FMA) recognized as different population stocks. The role of the intestinal parasite Synthesium pontoporiae (Digenea: Brachycladiidae) as a possible biological marker to differentiate P. blainvillei stocks was evaluated using nuclear and mitochondrial DNA markers. Internal transcribed sequence 1 and 2 (ITS1 and ITS2) regions of S. pontoporiae did not show intraspecific variability. The mitochondrial NADH dehydrogenase subunit 3 (ND3) and cytochrome oxidase subunit I (COI) gene sequences suggested lack of population structure in S. pontoporiae and population expansion. The apparent panmixia of S. pontoporiae may be due to the high mobility of one or more of its intermediary hosts. Alternatively, it may be due to the small sample size. This result is incongruent with the previously proposed FMA.


Subject(s)
Cestode Infections/veterinary , Dolphins/parasitology , Genetic Variation , Intestinal Diseases, Parasitic/veterinary , Platyhelminths/genetics , Platyhelminths/isolation & purification , Animals , Argentina , Brazil , Cestode Infections/epidemiology , Cestode Infections/parasitology , Electron Transport Complex IV/genetics , Endangered Species , Helminth Proteins/genetics , Intestinal Diseases, Parasitic/epidemiology , Intestinal Diseases, Parasitic/parasitology , Molecular Sequence Data , NADH Dehydrogenase/genetics , Phylogeny , Platyhelminths/classification , Platyhelminths/enzymology
5.
Braz. j. microbiol ; 43(2)Apr.-June 2012.
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469579

ABSTRACT

Isolation and genetic characterization of an environmental Vibrio cholerae O1 from the Amazon is reported. This strain lacks two major virulence factors - CTX and TCP - but carries other genes related to virulence. Genetic similarity with epidemic strains is evaluated and the importance of V. cholerae surveillance in the Amazon is emphasized.

6.
Braz. j. microbiol ; 43(2): 635-638, Apr.-June 2012. ilus
Article in English | LILACS | ID: lil-644480

ABSTRACT

Isolation and genetic characterization of an environmental Vibrio cholerae O1 from the Amazon is reported. This strain lacks two major virulence factors - CTX and TCP - but carries other genes related to virulence. Genetic similarity with epidemic strains is evaluated and the importance of V. cholerae surveillance in the Amazon is emphasized.


Subject(s)
Ecosystem , In Vitro Techniques , Polymerase Chain Reaction/methods , Surface Waters , Vibrio cholerae/genetics , Vibrio cholerae/isolation & purification , Environmental Microbiology , Virulence/genetics , Water Samples
8.
Braz J Microbiol ; 43(2): 635-8, 2012 Apr.
Article in English | MEDLINE | ID: mdl-24031874

ABSTRACT

Isolation and genetic characterization of an environmental Vibrio cholerae O1 from the Amazon is reported. This strain lacks two major virulence factors - CTX and TCP - but carries other genes related to virulence. Genetic similarity with epidemic strains is evaluated and the importance of V. cholerae surveillance in the Amazon is emphasized.

9.
Braz. j. med. biol. res ; 43(7): 657-662, July 2010. ilus, tab, graf
Article in English | LILACS | ID: lil-550729

ABSTRACT

The objective of the present study was to describe motor behavioral changes in association with histopathological and hematological findings in Wistar rats inoculated intravenously with human T-cell lymphotropic virus type 1 (HTLV-1)-infected MT2 cells. Twenty-five 4-month-old male rats were inoculated with HTLV-1-infected MT2 cells and 13 control rats were inoculated with normal human lymphocytes. The behavior of the rats was observed before and 5, 10, 15, and 20 months after inoculation during a 30-min/rat testing time for 5 consecutive days. During each of 4 periods, a subset of rats was randomly chosen to be sacrificed in order to harvest the spinal cord for histopathological analysis and to obtain blood for serological and molecular studies. Behavioral analyses of the HTLV-1-inoculated rats showed a significant decrease of climbing, walking and freezing, and an increase of scratching, sniffing, biting, licking, and resting/sleeping. Two of the 25 HTLV-1-inoculated rats (8 percent) developed spastic paraparesis as a major behavioral change. The histopathological changes were few and mild, but in some cases there was diffuse lymphocyte infiltration. The minor and major behavioral changes occurred after 10-20 months of evolution. The long-term observation of Wistar rats inoculated with HTLV-1-infected MT2 cells showed major (spastic paraparesis) and minor motor abnormalities in association with the degree of HTLV-1-induced myelopathy.


Subject(s)
Animals , Humans , Male , Rats , Human T-lymphotropic virus 1/physiology , Paraparesis, Tropical Spastic/virology , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Human T-lymphotropic virus 1/genetics , Polymerase Chain Reaction , Paraparesis, Tropical Spastic/blood , Paraparesis, Tropical Spastic/pathology , Time Factors , Viral Load
10.
Braz J Med Biol Res ; 43(7): 657-62, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20521016

ABSTRACT

The objective of the present study was to describe motor behavioral changes in association with histopathological and hematological findings in Wistar rats inoculated intravenously with human T-cell lymphotropic virus type 1 (HTLV-1)-infected MT2 cells. Twenty-five 4-month-old male rats were inoculated with HTLV-1-infected MT2 cells and 13 control rats were inoculated with normal human lymphocytes. The behavior of the rats was observed before and 5, 10, 15, and 20 months after inoculation during a 30-min/rat testing time for 5 consecutive days. During each of 4 periods, a subset of rats was randomly chosen to be sacrificed in order to harvest the spinal cord for histopathological analysis and to obtain blood for serological and molecular studies. Behavioral analyses of the HTLV-1-inoculated rats showed a significant decrease of climbing, walking and freezing, and an increase of scratching, sniffing, biting, licking, and resting/sleeping. Two of the 25 HTLV-1-inoculated rats (8%) developed spastic paraparesis as a major behavioral change. The histopathological changes were few and mild, but in some cases there was diffuse lymphocyte infiltration. The minor and major behavioral changes occurred after 10-20 months of evolution. The long-term observation of Wistar rats inoculated with HTLV-1-infected MT2 cells showed major (spastic paraparesis) and minor motor abnormalities in association with the degree of HTLV-1-induced myelopathy.


Subject(s)
Human T-lymphotropic virus 1/physiology , Paraparesis, Tropical Spastic/virology , Animals , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Human T-lymphotropic virus 1/genetics , Humans , Male , Paraparesis, Tropical Spastic/blood , Paraparesis, Tropical Spastic/pathology , Polymerase Chain Reaction , Rats , Time Factors , Viral Load
12.
Lett Appl Microbiol ; 45(4): 426-31, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17897387

ABSTRACT

AIM: Rapid characterization of variable region (VR)1 variants of the porA gene among invasive strains is crucial for outbreak management and epidemiology studies. Recent sequence analysis studies in Brazil showed that the VR1 P1.7 and P1.19 variants are highly prevalent, accounting for 68%, of the total number of VR1 variants characterized. The aim of this work is to develop a rapid polymerase chain reaction (PCR)-based method for genosubtyping Neisseria meningitidis by detection of porA variable regions P1.7 and P1.19. METHODS AND RESULTS: PCR primers for the detection of porA VR1 P1.7 and P1.19 were designed and tested using 198 clinical N. meningitidis isolates that had been previously evaluated by porA sequencing. All 50 strains with VR1 P1.7 and all 65 strains with VR1 P1.19 were positively identified by the respective VR-specific PCR and no false-positive reactions occurred. CONCLUSIONS: VR-specific PCR amplification accurately identified VR P1.7 and P1.19 strains. SIGNIFICANCE AND IMPACT OF THE STUDY: To overcome the disadvantages of serosubtyping and sequencing for typing the porA VR1 segment of N. meningitidis, we developed a PCR-based method to rapidly and accurately detect VR1 P1.7 and P1.19 variants. This approach is highly specific and sensitive; moreover it may allow for genotype determination of culture-negative samples.


Subject(s)
Meningococcal Infections/microbiology , Neisseria meningitidis/isolation & purification , Polymerase Chain Reaction , Porins/isolation & purification , Bacterial Typing Techniques , Brazil , DNA Primers , Humans , Meningococcal Infections/diagnosis , Neisseria meningitidis/genetics , Neisseria meningitidis/immunology , Porins/genetics , Porins/immunology
13.
Epidemiol Infect ; 135(4): 604-9, 2007 May.
Article in English | MEDLINE | ID: mdl-16959051

ABSTRACT

Previous serological studies on the Arara do Laranjal Indian group revealed extensive HTLV-2 infections. A collection of 97 new samples from the Arara were found repeatedly negative using three different commercial enzyme immunoassays. Eight samples that exhibited optical density readings close to the cut-off value were re-evaluated using Western blot (GeneLab 2.4, Singapore) assay. One sample was found to be non-reactive, five exhibited indeterminate patterns, one was classified as HTLV, and one was confirmed as HTLV-2. Peripheral blood mononuclear cell DNA of the eight samples were subjected to nested PCR and restriction fragment length polymorphism (RFLP) analysis of the pX and env regions, and nucleotide sequencing of the 5'-LTR region. All produced amplification products of pX, but env could be amplified in only one sample with the commonly used primers. RFLP analysis of the pX region using TaqI confirmed HTLV-2 infection. Nucleotide sequencing of the 5'-LTR region was performed in three samples (HTLV-2, HTLV and indeterminate based on Western blot pattern). Phylogenetic analysis of a 449-nt fragment using the Neighbour-Joining method clearly demonstrated that the three samples clustered within the HTLV-2c molecular subtype. The present study confirms the wide dissemination of the HTLV-2c subtype among linguistically and culturally distinct Amazonian Indian groups, and emphasizes the unique occurrence of infection by this subtype in Brazil. Moreover, it emphasizes the limitation of employing the present serological screening assays in blood banks, epidemiological studies, and the importance of molecular assays in the confirmatory procedures for the primary detection of HTLV-2 infections.


Subject(s)
HTLV-I Infections/immunology , HTLV-II Antibodies/blood , Human T-lymphotropic virus 2/isolation & purification , Phylogeny , Brazil/epidemiology , Immunoenzyme Techniques , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , RNA Viruses/isolation & purification , Sensitivity and Specificity
14.
J Med Virol ; 76(3): 386-90, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15902707

ABSTRACT

In the North of Argentina, an endemic area for HTLV-1, intrafamilial transmission of this virus has been observed. The HTLV-1 status in 13 family members of a seropositive blood donor from the central region of Argentina (non-endemic area) was investigated. According to serological and molecular assays, four members of this family (the blood donor, the husband, a son, and a daughter-in-law) proved to be HTLV-1 positive. LTR, tax, and env sequences from the provirus infecting the family members were identical. This strongly suggests the intrafamilial transmission of the virus. This study demonstrated intrafamilial transmission of HTLV-1 in a non-endemic area of Argentina.


Subject(s)
HTLV-I Infections/transmission , Human T-lymphotropic virus 1/genetics , Adult , Aged , Antibodies, Viral/blood , Argentina , DNA, Viral/chemistry , DNA, Viral/genetics , DNA, Viral/isolation & purification , Family Health , Female , Fluorescent Antibody Technique, Indirect , Gene Products, tax/genetics , Genes, env , Genes, pX , HTLV-I Infections/virology , Human T-lymphotropic virus 1/classification , Human T-lymphotropic virus 1/immunology , Human T-lymphotropic virus 1/isolation & purification , Humans , Immunoblotting , Male , Middle Aged , Molecular Sequence Data , Pedigree , Phylogeny , Proviruses/genetics , Sequence Analysis, DNA , Terminal Repeat Sequences
15.
Virus Genes ; 22(2): 181-6, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11324755

ABSTRACT

In Nigeria, the most populous country in Africa, the characterization of HIV-1 strains has been limited. In this study we evaluated the genetic diversity of the protease coding region, one of the anti-retroviral therapy target, and investigated the presence of mutations related to resistance to HIV protease inhibitors. We analyzed samples collected during 1996 and all patients were anti-retroviral drug naïves. Ten samples were evaluated by sequencing of the protease gene. The majority, 80%, were classified as subtype A and the two others were unclassified-divergent strains, something in between A and G subtypes. The gag region from these outliners were sequenced and the phylogenetic analysis classified them as subtype G. The protease amino acid consensus sequence of the Nigerian subtype A are in complete agreement with the consensus A differing from the USA subtype B consensus in 10 positions (L10V, I13V, K14R, I15V, K20I, M36I, R41K, P63L, H69K and L89M). The secondary substitutions associated with protease inhibitor resistance were observed in all Nigerian sequences at the positions L10V, M36I and L89M. The majority of sequence variation was concentrated in the interval between aminoacids 70-90 where the protease substrate binding region is located.


Subject(s)
Genetic Variation , HIV Infections/virology , HIV Protease Inhibitors/pharmacology , HIV Protease/genetics , HIV-1/genetics , Amino Acid Sequence , Base Sequence , DNA, Viral , Drug Resistance, Microbial , HIV-1/classification , HIV-1/drug effects , Humans , Molecular Sequence Data , Nigeria
16.
Appl Environ Microbiol ; 67(5): 2360-4, 2001 May.
Article in English | MEDLINE | ID: mdl-11319123

ABSTRACT

In this study, we demonstrated that analyzed strains of Vibrio mimicus and Vibrio cholerae could be separated in two groups by using multilocus enzyme electrophoresis (MEE) data from 14 loci. We also showed that the combination of four enzymatic loci enables us to differentiate these two species. Our results showed that the ribosomal intergenic spacer regions PCR-mediated identification system failed, in some cases, to differentiate between V. mimicus and V. cholerae. On the other hand, MEE proved to be a powerful molecular tool for the discrimination of these two species even when atypical strains were analyzed.


Subject(s)
Electrophoresis, Polyacrylamide Gel/methods , Vibrio cholerae/classification , Vibrio/classification , Bacterial Typing Techniques , Cholera/microbiology , Environmental Microbiology , Enzymes/genetics , Humans , Vibrio/genetics , Vibrio/isolation & purification , Vibrio Infections/microbiology , Vibrio cholerae/genetics , Vibrio cholerae/isolation & purification
17.
J Acquir Immune Defic Syndr ; 23(4): 327-31, 2000 Apr 01.
Article in English | MEDLINE | ID: mdl-10836755

ABSTRACT

This paper describes genetic subtypes of HIV-1 found in blood samples from 31 HIV-1-infected people who visited the Counseling and Testing AIDS Center of Instituto de Medicina Tropical in Manaus, Brazil. Manaus, the main city in Brazil's Amazon Basin, is also the closest urban connection for more than 100,000 Indians living in the rain forests of this region. Although to date there is no evidence of increased incidence of HIV-1 infection among the indigenous population, our understanding of both the prevalence and nature of the epidemic in the region as a whole is limited. From the 31 samples analyzed by C2V3 sequencing, we found almost equal proportions of HIV-1 strains belonging to subtype B (n = 16; 51.6%) and subtype F (n = 15; 48.4%), a finding that differs from results from previous studies conducted in urban areas of southeastern Brazil. We also observed the presence of the GWGR amino-acid sequence in the critical tetra-peptide crown of the env V3 loop in the HIV-1 subtype B samples analyzed. Among these samples, we also found 14 mosaic genomes (45.16%) in which different combinations of subtypes B, C, and F were identified between the p24 gag, pro, and env regions. Our data support the hypothesis that the Amazonian HIV-1 infections linked to the urban epidemic in southeastern Brazil. The genetic diversity and the prevalence of mosaic genomes among the isolates in our study confirm an integral role of recombination in the complex Brazilian epidemic.


Subject(s)
Disease Outbreaks , HIV Infections/epidemiology , HIV-1/classification , HIV-1/genetics , Recombination, Genetic , Adult , Brazil/epidemiology , DNA, Viral/analysis , Female , Gene Products, pol/genetics , HIV Core Protein p24/genetics , HIV Envelope Protein gp120/genetics , HIV Infections/virology , HIV Protease/genetics , HIV-1/isolation & purification , Humans , Indians, South American , Male , Middle Aged , Molecular Sequence Data , Peptide Fragments/genetics , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNA
18.
Infect Immun ; 68(3): 1700-5, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10678992

ABSTRACT

A Vibrio cholerae cytotoxin, designated VcVac, was found to cause vacuolation in Vero cells. It was originally detected in the pathogenic O1 Amazonia variant of V. cholerae and later shown to be produced in environmental strains and some El Tor strains. Comparison of VcVac production in various strains suggested that hemolysin was responsible for the vacuolating phenotype. Genetic experiments established a firm correlation between vacuolation and hemolysin production. The mammalian cell vacuolating activity of the V. cholerae hemolysin is a new property of this protein and points to a previously unknown type of interaction between V. cholerae and its host.


Subject(s)
Cytotoxins/toxicity , Escherichia coli Proteins , Hemolysin Proteins/toxicity , Macrolides , Vacuoles/drug effects , Vibrio cholerae/pathogenicity , Animals , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Bacterial Proteins/toxicity , Base Sequence , Chlorocebus aethiops , Hemolysin Proteins/genetics , Hemolysis , Molecular Sequence Data , Temperature , Vero Cells
19.
Infect Immun ; 68(2): 948-52, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10639469

ABSTRACT

A toxigenic non-O1/non-O139 strain of Vibrio cholerae (10259) was found to contain a new variant of the toxin-coregulated pilus (TCP) protein gene (tcpA) as determined by PCR and Southern hybridization experiments. Nucleotide sequence analysis data of the new tcpA gene in strain 10259 (O53) showed it to be about 74 and 72% identical to those of O1 classical and El Tor biotype strains, respectively. The predicted amino acid sequence of the 10259 TcpA protein shared about 81 and 78% identity with the corresponding sequences of classical and El Tor TcpA strains, respectively. An antiserum raised against the TCP of a classical strain, O395, although it recognized the TcpA protein of strain 10259 in an immunoblotting experiment, exhibited considerably less protection against 10259 challenge compared to that observed against the parent strain. Incidentally, the tcpA sequences of two other toxigenic non-O1/non-O139 strains (V2 and S7, both belonging to the serogroup O37) were determined to be almost identical to that of classical tcpA. Further, tcpA of another toxigenic non-O1/non-O139 strain V315-1 (O nontypeable) was closely related to that of El Tor tcpA. Analysis of these results with those already available in the literature suggests that there are at least four major variants of the tcpA gene in V. cholerae which probably evolved in parallel from a common ancestral gene. Existence of highly conserved as well as hypervariable regions within the sequence of the TcpA protein would also predict that such evolution is under the control of considerable selection pressure.


Subject(s)
Bacterial Outer Membrane Proteins/genetics , Fimbriae Proteins , Fimbriae, Bacterial/genetics , Vibrio cholerae/genetics , Amino Acid Sequence , Animals , Bacterial Outer Membrane Proteins/chemistry , Bacterial Outer Membrane Proteins/immunology , Base Sequence , Immune Sera/immunology , Mice , Molecular Sequence Data , Rabbits
20.
FEMS Microbiol Lett ; 171(1): 49-55, 1999 Feb 01.
Article in English | MEDLINE | ID: mdl-9987841

ABSTRACT

Polymerase chain reaction has been used to detect the presence of the virulence associated gene, tcpA and part of the promoter distal region of the toxin-co-regulated pilus cluster in non-O1, non-toxigenic, Vibrio cholerae. The amplified regions were characterised by restriction fragment length polymorphism and heteroduplex motility assay. We describe the nucleotide sequence of the tcpA gene fragment from non-toxigenic vibrios from clinical and environmental sources. The present study shows that there are at least three types of the tcpA gene among V. cholerae and the primers specific for the classical tcpA gene, amplify all biotypes. A sequence similarity in other regions of the toxin-co-regulated pilus cluster is suggested. The evidences for the presence of this cluster among non-toxigenic vibrios is, to our knowledge, reported for the first time. The use of restriction fragment length polymorphism for typing the tcpA and studying the alleles distribution is proposed.


Subject(s)
Alleles , Bacterial Outer Membrane Proteins/genetics , Fimbriae Proteins , Fimbriae, Bacterial/genetics , Genes, Bacterial , Vibrio cholerae/genetics , Base Sequence , Cloning, Molecular , Humans , Molecular Sequence Data , Polymorphism, Restriction Fragment Length , Sequence Alignment , Vibrio cholerae/chemistry , Vibrio cholerae/pathogenicity , Virulence/genetics
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