RESUMO
Soil carbon and its fractions are important in understanding the mechanism of soil carbon sequestration. The present study evaluated the impact of seven commercial bamboo species, viz., Bambusa balcooa, B. bambos, B. vulgaris, B. nutans, Dendrocalamus hamiltonii, D. stocksii, and D. strictus, on labile and non-labile carbon fractions. In the 0-15-cm layer, B. nutans had the highest very labile C (7.65 g kg-1) followed by B. vulgaris > B. balcooa > D. stocksii > D. hamiltonii > B. bambos > D. strictus > open. The active carbon pool was significantly low under the control plot (i.e. the open) indicating the positive influence of bamboo in soil C build-up in the top 0-15 cm soil layer. Amongst the different species of bamboo evaluated in this study, D. strictus accumulated the highest active C pool in 0-30-cm soil layer followed by B. vulgaris. Of the total organic C in the 0-30 cm soil depth, majority (55-60%) was contributed by the passive C pool comprising the less labile and the non-labile fraction of SOC. A high value of carbon stratification ratio (> 2) was observed for D. strictus, B. bambos, and D. hamiltonii which proves their potential for restoration of the degraded lands. The majority of bamboo species except for B. balcooa and D. stocksii showed a higher carbon management index than open systems, thereby indicating higher rates of soil C rehabilitation. Of the seven bamboo species, B. vulgaris, D. strictus, and B. nutans can be adopted for cultivation in the northwest Himalayas given their ability to positively impact the SOC and its fractions in both surface and sub-surface soil.
Assuntos
Carbono , Solo , Carbono/análise , Sequestro de Carbono , Monitoramento Ambiental , ÍndiaRESUMO
There are more than 350 real-time polymerase chain reaction (RT-PCR) coronavirus disease-2019 (COVID-19) testing kits commercially available but these kits have not been evaluated for pooled sample testing. Thus, this study was planned to compare and evaluate seven commercially available kits for pooled samples testing. Diagnostic accuracy of (1) TRUPCR SARS-CoV-2 Kit (Black Bio), (2) TaqPath RT-PCR COVID-19 Kit (Thermo Fisher Scientific), (3) Allplex 2019-nCOV Assay (Seegene), (4) Patho detect COVID-19 PCR kit (My Lab), (5) LabGun COVID-19 RT-PCR Kit (Lab Genomics, Korea), (6) Fosun COVID-19 RT-PCR detection kit (Fosun Ltd.), (7) Real-time Fluorescent RT-PCR kit for SARS CoV-2 (BGI) was evaluated on precharacterised 40 positive and 10 negative COVID-19 sample pools. All seven kits detected all sample pools with low Ct values (<30); while testing weak positive pooled samples with high Ct value (>30); the TRUPCR Kit, TaqPath Kit, Allplex Assay, and BGI RT-PCR kit showed 100% sensitivity, specificity, and accuracy. However, the Fosun kit, LabGun Kit, and Patho detect kit could detect only 90%, 85%, and 75% of weakly positive samples, respectively. We conclude that all seven commercially available RT-PCR kits included in this study can be used for routine molecular diagnosis of COVID-19. However, regarding performing pooled sample testing, it might be advisable to use those kits that performed best regarding positive identification in samples' pool, that is TRUPCR SARS-CoV-2 Kit, TaqPath RT-PCR COVID-19 Kit, Allplex 2019-nCOV Assay, and BGI Real-time RT-PCR kit for detecting SARS CoV-2.
Assuntos
Teste para COVID-19/métodos , COVID-19/diagnóstico , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , SARS-CoV-2/isolamento & purificação , COVID-19/epidemiologia , Técnicas de Laboratório Clínico , Humanos , Índia/epidemiologia , Estudos Prospectivos , RNA Viral/análise , RNA Viral/genética , República da Coreia , SARS-CoV-2/genética , Sensibilidade e Especificidade , Organização Mundial da SaúdeRESUMO
Mesenchymal tumors of the gastrointestinal tract which arise from the interstitial cells of Cajal and express C-Kit protein or CD117 on immunohistochemistry are known as gastrointestinal stromal tumors (GISTs). Extraperitoneal GISTs (EGISTs) are rare tumors arising from the mesentery, omentum, or retroperitoneum. We report a case of a 52-year-old male who presented with a huge abdominal lump arising from the right renal capsule that was found to be EGIST on histopathological examination and immunohistochemistry.
RESUMO
Traditionally injury care meant definitive repair following surgical exploration. However the outcome is poor because of deranged physiology in severely injured. Damage control surgery (DCS) is abbreviated initial procedure with subsequent correction of physiological imbalance, followed by definite repair. Tactical abbreviated surgical control (TASC) is application of principles of DCS techniques in the tactical environment. TASC is applied because of patient related factors (classic damage control) and limitations due to tactical reasons. Non-patient related factors only seen in tactical setting are, large numbers of patients arriving in short span, mobility of forward medical units, limitation of resources, and hostile environment. TASC involves only phase one of classical DCS. Complete correction of physiological imbalances and definitive surgery is carried out at a better equipped static hospital. TASC has shown to improve survival, extends benefit to greater number and helps to conserve precious resources. However TASC has its own limitations.
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Renal autotransplantation is a safe and effective procedure to reconstruct the urinary tract. The current indications for autotransplantation include renal vascular disease, severe ureteral damage, tumours of the kidney and ureter, complex nephrolithiasis and retroperitoneal fibrosis. We report a rare case where we had to perform renal autotransplantation along with hybrid surgery for aortic aneurysm repair. To our knowledge, this is the first case report of its kind for this specific condition.
Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Transplante de Rim , Adulto , Feminino , Humanos , Transplante de Rim/métodos , Procedimentos Cirúrgicos VascularesRESUMO
Due to extensive root system, connected rhizome bamboos are considered suitable for improving soil properties within a short period, though most of the claims are anecdotal and need to be supported with quantified data. The study evaluates seven bamboo species viz., Bambusa balcooa, Bambusa bambos, Bambusa vulgaris, Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii and Dendrocalamus strictus for their rooting pattern and impact on soil health properties. Coarse and fine root intensity was maximum in B. vulgaris. Coarse root biomass ranged from 0.6 kg m-3 in B. nutans to 2.0 kg m-3 in B. vulgaris and B. bambos. Fine root biomass ranged from 1.1 kg m-3 in B. nutans to 4.5 kg m-3 in D. hamiltonii. Contribution of fine roots in terms of intensity and biomass was much higher than coarse roots. Fine root biomass showed declining trend with increase in soil depth in all the species. During sixth year, the litter fall ranged from 8.1 Mg ha-1 in D. stocksii to 12.4 Mg ha-1 in D. hamiltonii. Among soil physical properties significant improvement were recorded in hydraulic conductivity, water stable aggregates and mean weight diameter. Soil pH, organic carbon and available phosphorus under different species did not reveal any significant changes, while significant reduction was observed in total nitrogen and potassium. Significant positive correlation was observed between WSA and iron content. Soil microbial population and enzyme activities were higher in control plot. Considering root distribution, biomass, soil hydraulic conductivity and water stable aggregates, B. bambos, B. vulgaris and D. hamiltonii are recommended for rehabilitation of degraded lands prone to soil erosion.
Assuntos
Bambusa/crescimento & desenvolvimento , Biomassa , Nitrogênio/análise , Fósforo/análise , Raízes de Plantas/crescimento & desenvolvimento , Solo/química , Água/química , ÍndiaRESUMO
BACKGROUND: Researchers are challenged with identification of possible feed additives with the ability to increase the efficiency of feed utilization. AIMS: The present work aimed at studying growth pattern and carcass traits in broiler fed on dietary enzymes (Enzymex) and probiotic (Yeamark) over a period of six weeks. METHODS: A completely randomized design, including 8 treatments, 3 replications and 15 birds in each experimental unit was applied. Results: The results showed that feed intake decreased significantly (P<0.05) which might be due to the birds fulfilling their nutrient requirements by taking less amount of feed with improved digestibility of energy sources and amino acids. The results of present study also demonstrate the beneficial effects on performance and dressed yield in the treated groups in broiler. CONCLUSION: Enzymes and probiotic are, therefore, suggested to be used as feed additives in broiler rations for higher profitability.
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Male andropause, male climacteric or viropause is a condition in which men suffer from complex symptomatology due to low androgen level with aging. After the age of 40 years testosterone level starts declining and andropause corresponds to the age at which a pathogenic threshold is reached. This review summarizes the etiology, consequences, screening, diagnosis, monitoring of androgen deficiency in aging male (ADAM). The pros and cons of testosterone replacement therapy (TRT) in elderly male have been discussed. Currently oral, transdermal, transbuccal, intramuscular, and subcutaneous implants are available for clinical use. The choice is made by physicians based on therapeutic indication and patient preferences.
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Two groups of 20 male Sprague-Dawley rats each were given sc 8 mg azoxymethane/kg body weight and fed a normal diet or one high in beef fat. Control groups were not given azoxymethane. Fat-control animals did not excrete more total bile acids than did the normal-control group but did excrete more deoxycholic acid as the result of increased cholic acid degradation. Azoxymethane itself caused an increase in fecal bile acid concentratation but tended to reduce the level of cholic acid degradation. Fatty acid content in the feces increased in the animals on the fat diet but was not affected by azoxymethane. A fat-diet-dependent increase was apparent in total fecal neutral steroids and a carcinogen-dependent increase in cholesterol degradation. Dietary fat and bile steroids altered by gut microflora were important interrelated factors in the intestinal carcinogenic process of this animal model.
Assuntos
Ácidos e Sais Biliares/metabolismo , Gorduras na Dieta , Fezes/análise , Neoplasias Intestinais/metabolismo , Carne , Animais , Azoximetano , Colesterol/metabolismo , Ácidos Cólicos/metabolismo , Cocarcinogênese , Ácido Desoxicólico/metabolismo , Ácidos Graxos/metabolismo , Neoplasias Intestinais/induzido quimicamente , Neoplasias Intestinais/etiologia , Masculino , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/etiologia , Neoplasias Experimentais/metabolismo , RatosRESUMO
Two groups of 20 male Sprague-Dawley rats each were given azoxymethane subcutaneously (8 mg/kg body wt) and fed a normal diet or one high in beef fat. Control groups were not given azoxymethane. The rats on the fat diet consumed less food and gained significantly more weight than the animals on the normal diet. Those given high fat and azoxymethane developed more intestinal tumors than did the dietary controls receiving the carcinogen. Furthermore, they had a greater number of larger tumors and more metastases than did the animals fed normally. No intestinal tumors were observed in control groups not receiving azoxymethane. The results show that the diet high in beef fat enhances the carcinogenic effect of azoxymethane in the rat.
Assuntos
Compostos Azo , Carcinógenos , Gorduras na Dieta , Neoplasias Intestinais/induzido quimicamente , Carne , Animais , Peso Corporal , Ingestão de Alimentos , Masculino , Metástase Neoplásica , Neoplasias Experimentais/induzido quimicamente , Óxidos de Nitrogênio , RatosRESUMO
The effect of the fecal stream on intestinal carcinogenesis with azoxymethane was studied in male rats. Colostomies were performed approximately 2 cm distal to the cecum in 50 Sprague-Dawley rats to produce a 20-cm segment of nonfunctional large bowel; an additional 50 animals were left intact. Each of these groups was divided equally and was fed a normal diet or a diet containing 2% cholestyramine by weight. All animals were given azoxymethan s.c. At the end of 7 months all rats were sacrificed. The animals with colostomies developed significantly fewer tumors in the defunctionalized bowel than did intact animals in the same bowel segment. Cholestyramine appeared to increase the tumor yield in the large bowel of the intact animals but had no effect on the number of tumors in the defunctionalized bowel. Further, the intact animals on both dietary regimens developed a greater number of large tumors in the distal 20 cm of bowel. The results show that the fecal stream alters the carcinogenic activity of azoxymethane in the large bowel of the rat. It also appears that the carcinogen can reach its target tissue by a route other than the fecal stream.
Assuntos
Compostos Azo/toxicidade , Carcinógenos , Neoplasias do Colo/induzido quimicamente , Fezes , Animais , Resina de Colestiramina/farmacologia , Colostomia , Masculino , Neoplasias Experimentais/induzido quimicamente , RatosRESUMO
Rodent and human mammary tumor systems were investigated to relate the steroid alcohol and estrogen sulfotransferase activities to the hormoanl dependency of the tumor as determined by estrogen receptor content. Unlike the normal mammary gland or the hyperplastic alveolar nodule, rodent mammary neoplasms displayed significant levels of these two sulfotransferases. In the hormone-independent mouse tumors produced from out-growth lines D1, D2, and D8, high dehydroepiandrosterone sulfotransferase activity was characteristic of the rapidity with which hyperplastic alveolar nodules developed into a neoplasms (V-max = 52.8 versus 1.8 fmoles/min/mg protein) while estrone sulfotransferase activity was either not detectable or low (V-max = 5.5 fmoles). After oophorectomy of mice bearing slowly developing tumors, both sulfotransferases in the nonregressing neoplasms showed marked increases in activity (V-max dehydroepiandrosterone = 30.0 fmoles; V-max estrone = 18.5 fmoles). Strain differences not the estrogen receptor content of hormone-dependent rat mammary tumors. In Wistar-Lewis rats the steroid alcohol sulfotransferase activity was at least 35 times higher than in the Sprague-Dawley strain. As was observed in the mouse mammary tumor, Sprague-Dawley rat neoplasms that grew in the absence of ovarian hormones contained significantly greater levels of the steroid alcohol sulfotransferase. Possible correlaion between presence of the steroid alcohol sulfotransferase and the estrogen receptor protein was observed in a limited number of human breast carcinomas.
Assuntos
Neoplasias da Mama/enzimologia , Neoplasias Mamárias Experimentais/enzimologia , Receptores de Superfície Celular , Sulfurtransferases/metabolismo , Álcoois , Animais , Castração , Embrião de Galinha , Desidroepiandrosterona , Estrogênios , Estrona , Feminino , Humanos , Cinética , Ovário , Lesões Pré-Cancerosas/enzimologia , Ratos , Ratos Endogâmicos LewRESUMO
OBJECTIVES: To examine eight strains of Vibrio cholerae O1 isolated in 2003 and 2005 from Puri, India, for antibiotic susceptibility, presence of virulence and regulatory genes, cholera toxin (CT) production, CTX arrangement and genomic profiles. MATERIALS AND METHODS: Bacterial strains were tested for antibiotic susceptibility using disc diffusion assay. Polymerase chain reaction determined the presence of antibiotic resistance, virulence and regulatory genes. To determine the type of cholera toxin subunit B (ctxB), nucleotide sequencing was performed. Southern hybridisation determined the number and arrangement of CTXΦ. Ribotyping and pulsed-field gel electrophoresis (PFGE) were used to determine the genomic profile of isolates. RESULTS: All the eight strains, except one strain, showed resistant to nalidixic acid, sulphamethoxazole, streptomycin and trimethoprim and possessed the sullI, strB, dfrA1 and int SXT genes. All the strains carried the toxin-co-regulated pilus pathogenicity island, the CTX genetic element, the repeat in toxin and produced CT. Restriction fragment length polymorphism (RFLP) analysis showed that V. cholerae O1 possess a single copy of the CTX element flanked by tandemly arranged RS element. Nucleotide sequencing of the ctxB gene showed the presence of classical ctxB. RFLP analysis of conserved rRNA gene showed two ribotype patterns. PFGE analysis also showed at least three PFGE patterns, irrespective of year of isolations, indicating the genomic relatedness among them. CONCLUSION: Overall, these data suggest that classical ctxB-positive V. cholerae O1 El Tor strains that appeared in 2003 continue to cause infection in 2005 in Puri, India, and belong to identical ribotype(s) and/or pulsotype(s). There is need to continuous monitor the emergence of variant of El Tor because it will improve our understanding of the evolution of new clones of variant of V. cholerae.
Assuntos
Antibacterianos/farmacologia , Toxina da Cólera/genética , Cólera/microbiologia , Farmacorresistência Bacteriana , Variação Genética , Vibrio cholerae O1/classificação , Vibrio cholerae O1/genética , Bacteriófagos/genética , Southern Blotting , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eletroforese em Gel de Campo Pulsado , Genótipo , Humanos , Índia , Epidemiologia Molecular , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Ribotipagem , Análise de Sequência de DNA , Vibrio cholerae O1/isolamento & purificação , Fatores de Virulência/genéticaRESUMO
Our laboratory has designed a specific nested-PCR (N-PCR) assay, based on the hupB gene of Mycobacterium tuberculosis (Rv2986c) and Mycobacterium bovis (Mb3010c) as a method to differentiate these closely related species. The present paper deciphers the utility of this assay for identification of pathogenic Mycobacteria in clinical samples. Extra-pulmonary clinical samples obtained from cattle and humans were investigated. Pre-dominance of M. tuberculosis (15.7%) and M. bovis (26.8%) was seen in humans and cattle, respectively. However, more importantly, both mycobacterial pathogens (mixed infection) were identified in a number of samples. In humans 8.7% of the samples and 35.7% in cattle were classified as mixed infection. The detection of mixed infection with the mycobacterial pathogenic duo in humans and bovines denotes the prospect of potential transmission of these pathogens from humans to cattle (zoonosis) and vice versa (reverse zoonosis).
Assuntos
Tuberculose Bovina/transmissão , Tuberculose/microbiologia , Zoonoses , Animais , Proteínas de Bactérias , Técnicas de Tipagem Bacteriana , Bovinos , DNA Bacteriano/análise , Histonas/genética , Humanos , Índia , Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Tuberculose/diagnóstico , Tuberculose Bovina/diagnósticoRESUMO
A simple reversed-phase liquid chromatographic method is developed for the simultaneous quantitation of the anticancerous drugs vincristine, vinblastine, and their precursors catharanthine and vindoline using a Merck Chromolith Performance reversed-phase high-performance liquid chromatography column. A better resolution is obtained in comparison with available particulate-type C18 columns. The column provides good reproducibility and peak symmetry. Chromatography is carried isocratically with a mobile phase of acetonitrile-0.1M phosphate buffer containing 0.5% glacial acetic acid (21:79, v/v; pH 3.5) at a flow rate of 1.2 mL/min and UV detection at 254 nm. Parameters such as linearity, limits of quantitation (LOQ) and detection (LOD), precision, accuracy, recovery, and robustness are studied. The method is selective and linear for alkaloid concentration in the range 0.25 microg-25 microg/mL. The LOQ and LOD are 25, 46, 56, and 32 microg/mL and 8, 14, 18, and 10 microg/mL, respectively. The results of accuracy studies are good. Values for coefficient of variation are 2.50, 1.82, 1.33, and 1.13, respectively. The percent recovery of the alkaloids was found to be 96%, 97%, 98%, and 98%, respectively. Peak purity and homogeneity of these compounds in plant extract is studied using a photodiode-array detector. This simple and rapid method of analysis is applied for the determination of these alkaloids in a large number of leaf extracts of Catharanthus roseus..
Assuntos
Catharanthus/química , Cromatografia Líquida de Alta Pressão/métodos , Folhas de Planta/química , Vimblastina/análogos & derivados , Vimblastina/análise , Alcaloides de Vinca/análise , Vincristina/análise , Calibragem , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Vibrio cholerae is an autochthonous inhabitant of fresh and brackish water and estuarine system. Investigation of V. cholerae from the River Ganga seems important to find variation in CTX arrangement and genomic diversity. OBJECTIVES: To investigate V. cholerae O1 strains for the presence of virulence and regulatory genes, variation in number and organisation of the pre-CTXΦ and/or CTXΦ, and for the genomic diversity. MATERIALS AND METHODS: Polymerase chain reaction (PCR) was used to detect virulence and regulatory genes, type of rstR and location of CTXΦ on the chromosome. Southern hybridisation was conducted to see the number and arrangement of pre-CTXΦ and CTXΦ. Ribotyping and pulsed-field gel electrophoresis were used to find genetic relatedness. RESULTS: Seven strains gave positive results by PCR for the gene encoding for ctx A, zot, ace, tcp A (El Tor), omp U, and tox R, except one strain that was negative for the ctx A. Three strains were positive for the tcp A (El Tor), omp U and tox R genes. Determination of CTX organisation showed that among the ctx-positive strains, four harboured two copies of CTXETΦ arranged in tandem and two harboured one copy of CTXETΦ, and one ctx-negative strain harboured only one copy of pre-CTXETΦ. Pulsotype and ribotype analysis showed existence of at least three pulsotype and ribotypes indicating diversity in genomic content among them. CONCLUSION: This study thus indicates that multiple clones (ribotypes/pulsotypes) of V. cholerae O1 carrying pre-CTXΦ and/or CTXΦ and ctx-negative strains were present in the water of the River Ganga, Varanasi, India.
Assuntos
Variação Genética , Rios/microbiologia , Vibrio cholerae O1/classificação , Vibrio cholerae O1/isolamento & purificação , Southern Blotting , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Genes Reguladores , Genótipo , Índia , Reação em Cadeia da Polimerase , Prófagos/genética , Ribotipagem , Vibrio cholerae O1/genética , Fatores de Virulência/genéticaRESUMO
Thyroid follicular cell tumors arise in rodents from mutations, perturbations of thyroid and pituitary hormone status with increased stimulation of thyroid cell growth by thyroid-stimulating hormone (TSH), or a combination of the two. The only known human thyroid carcinogen is ionizing radiation. It is not known for certain whether chemicals that affect thyroid cell growth lead to human thyroid cancer. The U.S. Environmental Protection Agency applies the following science policy positions: 1) chemically induced rodent thyroid tumors are presumed to be relevant to humans; 2) when interspecies information is lacking, the default is to assume comparable carcinogenic sensitivity in rodents and humans; 3) adverse rodent noncancer thyroid effects due to chemically induced thyroid-pituitary disruption are presumed to be relevant to humans; 4) linear dose-response considerations are applied to thyroid cancer induced by chemical substances that either do not disrupt thyroid functioning or lack mode of action information; 5) nonlinear thyroid cancer dose-response considerations are applied to chemicals that reduce thyroid hormone levels, increase TSH and thyroid cell division, and are judged to lack mutagenic activity; and 6) nonlinear considerations may be applied in thyroid cancer dose-response assessments on a case-by-case basis for chemicals that disrupt thyroid-pituitary functioning and demonstrate some mutagenic activity. Required data for risk assessment purposes is mode of action information on mutagenicity, increases in follicular cell growth (cell size and number) and thyroid gland weight, thyroid-pituitary hormones, site of action, correlations between doses producing thyroid effects and cancer, and reversibility of effects when dosing ceases.
Assuntos
Adenocarcinoma Folicular/induzido quimicamente , Carcinógenos/efeitos adversos , Glândula Tireoide/efeitos dos fármacos , Neoplasias da Glândula Tireoide/induzido quimicamente , Adenocarcinoma Folicular/fisiopatologia , Animais , Humanos , Ratos , Medição de Risco , Glândula Tireoide/fisiologia , Neoplasias da Glândula Tireoide/fisiopatologiaRESUMO
Fifteen isolates of Aeromonas media (seven from diarrhoeal stools, four from water and four from superficial skin ulcers of catfish) were examined for enterotoxin production. Ten of these isolates (six diarrhoeal, one from water and three from fish) caused accumulation of fluid in the initial rabbit ileal loop (RIL) tests. Isolates from diarrhoeal stools and fish caused relatively more fluid accumulation than those from water. Those strains that caused little or no fluid accumulation in the initial experiments became enterotoxin producers after one passage through RILs, regardless of source, and also showed gradual enhancement of fluid outpouring after each subsequent passage. Inocula of c. 1 x 10(4) viable cells and 0.25 ml of culture filtrate (CF) caused fluid accumulation similar to that of toxigenic Vibrio cholerae 569B. The enterotoxic factor(s) were inactivated when held at 56 degrees C for 20 min or 65 degrees C for 10 min and showed biological activity over a wide range of pH values. These results suggest that strains of A. media, whether from diarrhoeal stools, water or infected fish, are potentially enterotoxigenic and may have the potential to produce a heat-labile and pH-stable diarrhoeagenic factor in the same way as other known heat-labile and pH-stable enterotoxins.
Assuntos
Aeromonas/patogenicidade , Toxinas Bacterianas/toxicidade , Enterotoxinas/toxicidade , Proteínas de Escherichia coli , Animais , Toxinas Bacterianas/análise , Peixes-Gato , Enterotoxinas/análise , Humanos , Concentração de Íons de Hidrogênio , Íleo/efeitos dos fármacos , Íleo/metabolismo , Coelhos , TemperaturaRESUMO
Of 97 isolates of Aeromonas spp. that were examined for haemagglutination (HA) and enterotoxigenicity, 35 were from clinical and 62 from environmental sources; 66 of them were also screened for sensitivity to normal human serum (NHS). HA was caused by 44 isolates (45%); it was unrelated to the source of the strain, but it was caused by a higher proportion of the isolates of A. hydrophila than of A. sobria or A. caviae. Of the haemagglutinating strains, 82% were enterotoxigenic, whereas most of the non-haemagglutinating strains were non-toxigenic when tested initially. All the latter became enterotoxin producers after serial passage through rabbit ileal loops, but without change in HA. Most (64%) of the isolates, including 68% of A. caviae (72% of clinical and 65% of environmental), were resistant to the bactericidal action of NHS. Most (92%) of the serum-sensitive strains were killed by activation of both the classical and alternate pathways of complement, the others only by the alternate pathway. Most (74%) of the serum-resistant strains caused fluid accumulation in the initial tests in ileal loops, regardless of species or source. Haemagglutinating and serum-resistant strains caused significantly more accumulation of fluid (p < 0.05) than non-haemagglutinating and serum-sensitive strains. This study shows partial correlation between HA or serum sensitivity and enterotoxigenicity, but the properties are probably not genetically linked.
Assuntos
Aeromonas/metabolismo , Diarreia/microbiologia , Enterotoxinas/biossíntese , Infecções por Bactérias Gram-Negativas/microbiologia , Hemaglutinação , Adulto , Aeromonas/imunologia , Aeromonas/patogenicidade , Aeromonas hydrophila/imunologia , Aeromonas hydrophila/metabolismo , Aeromonas hydrophila/patogenicidade , Atividade Bactericida do Sangue , Criança , HumanosRESUMO
Of 147 isolates of three species of Aeromonas, 54 were from clinical and 93 from environmental sources. When tested for enterotoxin production, most of the isolates (56%) caused accumulation of fluid in rabbit ileal loops (RILs). Although large proportions of clinical and environmental isolates of A. caviae (55% and 65%, respectively) elicited such a response in RILs, isolates of A. hydrophila and A. sobria produced significantly more fluid (p less than 0.05). Furthermore, the environmental strains of A. hydrophila and A. sobria produced more fluid than the clinical isolates (p less than 0.05). The strains of Aeromonas spp. that caused little or no fluid accumulation in the initial experiments became enterotoxin producers after 1-3 passages through RILs, regardless of their source, and showed gradual enhancement of fluid outpouring after each passage. The present study suggests that all strains of these species of Aeromonas are potentially enterotoxigenic, whether from clinical or environmental sources.