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1.
Five hundred diarrhoeal stool samples from the University of Port Harcourt Teaching Hospital were investigated for enteropathogenic Escherichia coli. Results showed that the organism was endemic in Port Harcourt metropolis and was responsible for about 15% of the incidence of infantile diarrhoea in the community. Detailed analysis revealed that 13 serotypes were involved. It was also observed that babies aged between 0 and 18 months were more susceptible than those aged between 19 and 36 months. Male infants were also shown to be more at risk than females. Antibiotic sensitivity tests showed that the enteropathogenic E. coli isolated were highly resistant to most common antimicrobial drugs but were highly sensitive to genticin and cefotaxime.  相似文献   

2.
The bacteriological quality of some rural water supplies in Port Harcourt was monitored over a 3 month period. The supplies were unsatisfactory as judged by standard plate counts (103/ml) and the presence of presumptive and faecal coliforms and Staphylococcus aureus. The recovery of potentially pathogenic bacteria (e.g. Pseudomonas aeruginosa ) further substantiated the existence of health hazards. The most frequently isolated coliforms were Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoniae. Coliform contamination was greater in well water than in river or stream water samples. An antibiotic sensitivity test revealed that 17.5–27.2% of E. coli strains were resistant to three or more antibiotics. Escherichia coli isolated from well water samples exhibited the greatest degree of multiple resistance. Some strains were resistant to all the six antibiotics tested. The danger of an epidemic of waterborne diseases in the communities as a result of drinking water from these non-potable sources is noted.  相似文献   

3.
The bacteriological quality of some rural water supplies in Port Harcourt was monitored over a 3 month period. The supplies were unsatisfactory as judged by standard plate counts (10(3)/ml) and the presence of presumptive and faecal coliforms and Staphylococcus aureus. The recovery of potentially pathogenic bacteria (e.g. Pseudomonas aeruginosa) further substantiated the existence of health hazards. The most frequently isolated coliforms were Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoniae. Coliform contamination was greater in well water than in river or stream water samples. An antibiotic sensitivity test revealed that 17.5-27.2% of E. coli strains were resistant to three or more antibiotics. Escherichia coli isolated from well water samples exhibited the greatest degree of multiple resistance. Some strains were resistant to all the six antibiotics tested. The danger of an epidemic of waterborne diseases in the communities as a result of drinking water from these non-potable sources is noted.  相似文献   

4.
S D Abbey 《Microbios》1987,49(199):73-77
The Port Harcourt metropolis of Nigeria was screened to establish the prevalence of asymptomatic bacteriuria (ABU) over a 3 year period. An occurrence rate of 15% was detected. The females presented a higher incidence rate (9%) than the males (6%). Previous history of urinary tract infection (UTI) was seen to be contributory to ABU; so also was sexual activity. Of the isolates obtained, Escherichia coli was found to be predominant (45%). An isolation rate of 3.7% was realised for Staphylococcus epidermidis. This emphasizes its role in UTI. The advantages of screening for ABU was examined and it is suggested that individuals should be screened for ABU at least twice a year.  相似文献   

5.
Samples from municipal waste water, the Bonny River estuary and wells in and around Port Harcourt were examined for bacteriological quality over a 9 month period. A total of 157 Pseudomonas spp., 133 Escherichia coli and 282 other coliforms were isolated and tested for the incidence of resistance to 10 antibiotics. All of the Pseudomonas spp. were resistant to at least one of the antibiotics while 96.2% were resistant to two or more. Most (83.5%) of the E. coli and other coliforms (91.8%) were resistant to at least one antibiotic. All strains were susceptible to gentamicin. Minimal inhibitory concentrations of ampicillin and tetracycline for E. coli ranged from 6.25 to 50 and 6.25 to 12.5 micrograms/ml, respectively. Minimal inhibitory concentrations of ampicillin and tetracycline were 1000 and 25 micrograms/ml for the Pseudomonas strains. The high incidence of bacterial resistance to antibiotics is discussed in relation to the widespread use of antibiotics, and possible public health implications.  相似文献   

6.
The espA, espB and espD genes from enteropathogenic Escherichia coli were previously shown to be essential for triggering the signal transduction in infected host cells. We have cloned and determined the nucleotide sequences of the espA, espB and espD homologues from an E. coli strain (4221) isolated from a dog which manifested the attaching and effacing lesions in the small intestine. This strain is designated as a dog enteropathogenic E. coli. When comparing predicted amino acid sequences to those of the corresponding proteins from enteropathogenic E. coli O127, enterohemorrhagic E. coli serotype O26, enterohemorrhagic E. coli O157 and rabbit enteropathogenic E. coli, the EspADEPEC protein showed the same level of similarity (75% identity) with EspA of enteropathogenic E. coli O127 and rabbit enteropathogenic E. coli. The EspBDEPEC protein showed the highest similarity with the EspB of enteropathogenic E. coli O127 (99% identity). The EspDDEPEC protein showed 88% identity with the EspDEPEC. We constructed and purified a maltose-binding fusion protein containing the product of the entire espBDEPEC gene of the dog enteropathogenic E. coli strain 4221. Purified maltose-binding protein-EspBDEPEC fusion protein was shown to bind efficiently to HEp-2 cells in a localized fashion as shown by immunofluorescence microscopy. In addition, when the dog enteropathogenic E. coli strain 4221 was grown in tissue culture medium (DMEM) supplemented with serum, a secreted 36-kDa protein was identified by immunoblot analysis using a polyclonal antiserum against the maltose-binding protein-EspBDEPEC fusion protein.  相似文献   

7.
Flesh, gill or head tissues of fresh or smoked potassium sorbate (PS) treated and untreated mullet (Mugil cephalus) were evaluated for microbiological and physicochemical quality. Smoked, PS-treated and untreated mullet were further smoked after 3 days of initial smoking and stored (29±2°C). Overall microbial load was significantly higher in heads than in either flesh or gills. Conversely, with smoking, significant maximum load occurred in the flesh of PS-treated and in untreated mullet but the gills showed the lowest incidence. Coliform and staphylococci decreased markedly following final smoking but lactobacilli and fungi increased considerably following different lag periods. Lower counts occurred in PS-treated samples. The pH initially increased but decreased sharply after the final smoking. Moisture content decreased markedly on smoking and increased slightly during storage with gill tissues being highest.The authors are with the Department of Microbiology, Food and Industrial Division, University of Port Harcourt, PMB 5323, PO Box 148 Port Harcourt, Nigeria.  相似文献   

8.
Samples from municipal waste water, the Bonny River estuary and wells in and around Port Harcourt were examined for bacteriological quality over a 9 month period. A total of 157 Pseudomonas spp., 133 Escherichia coli and 282 other coliforms were isolated and tested for the incidence of resistance to 10 antibiotics. All of the Pseudomonas spp. were resistant to at least one of the antibiotics while 96.2% were resistant to two or more. Most (83.5%) of the E. coli and other coliforms (91.8%) were resistant to at least one antibiotic. All strains were susceptible to gentamicin. Minimal inhibitory concentrations of ampicillin and tetracycline for E. coli ranged from 6.25 to 50 and 6.25 to 12.5 μg/ml, respectively. Minimal inhibitory concentrations of ampicillin and tetracycline were 1000 and 25 μg/ml for the Pseudomonas strains. The high incidence of bacterial resistance to antibiotics is discussed in relation to the widespread use of antibiotics, and possible public health implications.  相似文献   

9.
Previous studies on the normal values of serum iron, unsaturated iron binding capacity, total iron binding capacity, serum transferrin, percent transferrin saturation, red cell distribution width, and various platelet indices: Platelet count, mean platelet volume, platelet distribution width, plateletcrit and platelet larger cell ratio in pregnant subjects in Nigeria are relatively scanty. Present study aims to determine the values of these parameters in apparently healthy pregnant subjects residing in Port Harcourt south eastern Nigeria; and help establish normal reference ranges of these parameters for the population under reference. Cross sectional prospective study involving 220 female subjects attending for the first time, the ante-natal clinics of a tertiary health care facility in Port Harcourt. Subjects were divided into 73, 75 and 72 subjects in the first, second and third trimester of pregnancy respectively. Serum iron and unsaturated iron binding capacity, red cell distribution width, platelet count and platelet distribution width were determined by automated methods; total iron binding capacity, serum transferrin concentrations, percent transferrin saturation, mean platelet volume and plateletcrit were calculated using appropriate formulas. The values of serum iron, unsaturated iron binding capacity, total iron binding capacity and serum transferrin concentrations were found to show significant variations between the various trimesters of pregnancy. However, while serum iron showed significant decreases during pregnancy; unsaturated iron binding capacity, total iron binding capacity and serum transferrin concentrations were found to show significant increases during pregnancy amongst our subjects. By contrast the values of red cell distribution width, platelet count, mean platelet volume, platelet distribution width, plateletcrit and platelet larger cell ratio did not show any significant differences at the different trimesters of pregnancy in our subjects. The present study reports, for the first time, normative values for these parameters in apparently healthy pregnant subjects in Port Harcourt south eastern Nigeria. Apparently, increases in unsaturated and total iron binding capacity and serum transferrin values seen amongst our subjects with increasing gestation may perhaps be a mechanism to ensure a fetal adequate iron delivery on account of the decreasing serum iron concentration with gestation in our subjects. The study suggests that values of serum transferrin are perhaps a more useful screening tool for iron deficiency anemia during pregnancy amongst our subjects.  相似文献   

10.
Shiga toxin-producing Escherichia coli (STEC) is an important cause of food-borne illness in humans. Ruminants appear to be more frequently colonized by STEC than are other animals, but the reason(s) for this is unknown. We compared the frequency, magnitude, duration, and transmissibility of colonization of sheep by E. coli O157:H7 to that by other pathotypes of E. coli. Young adult sheep were simultaneously inoculated with a cocktail consisting of two strains of E. coli O157:H7, two strains of enterotoxigenic E. coli (ETEC), and one strain of enteropathogenic E. coli. Both STEC strains and ETEC 2041 were given at either 10(7) or 10(10) CFU/strain/animal. The other strains were given only at 10(10) CFU/strain. We found no consistent differences among pathotypes in the frequency, magnitude, and transmissibility of colonization. However, the STEC strains tended to persist to 2 weeks and 2 months postinoculation more frequently than did the other pathotypes. The tendency for persistence of the STEC strains was apparent following an inoculation dose of either 10(7) or 10(10) CFU. One of the ETEC strains also persisted when inoculated at 10(10) CFU. However, in contrast to the STEC strains, it did not persist when inoculated at 10(7) CFU. These results support the hypothesis that STEC is better adapted to persist in the alimentary tracts of sheep than are other pathotypes of E. coli.  相似文献   

11.
The effect of variation of pH and temperature on the lectinophagocytosis of enteropathogenic Escherichia coli by polymorphonuclear leukocytes and macrophages elicited by thioglycolate medium was evaluated. The phagocytosis of enteropathogenic E. coli is dependent on pH, being maximal at pH 7.0 and reduced at pH 5.5 or 6.0. Mannan and mannose (as representative sugars that bind to phagocyte lectin receptors), are recognized by mannose receptors and reduced the phagocytic index at pH 7.0 (from 41.6 +/- 8.5 to 17.0 +/- 6.1) and at pH 6.0 (from 24.1 +/- 5.1 to 14.5 +/- 5.0), suggesting that mannose receptors, despite their reduced affinity for ligand at pH 6.0, also participate in phagocytosis of enteropathogenic E. coli. The inhibition of phagocytosis by anti-substance A antibody was also examined at pH 7.0 and at pH 6.0, decreasing (from 41.6 +/- 8.5 to 21.1 +/- 3.4) and (from 24.1 +/- 5.1 to 12.0 +/- 3.5), respectively. This antibody reduced the phagocytosis of enteropathogenic E. coli in phagocytic assays at 37 or 41 degrees C. These results suggest that the acidic pH decreased the affinity of mannose receptors to ligands on the surface of E. coli and also affected the binding of lectin from E. coli to N-acetylgalactosamine on phagocytes.  相似文献   

12.
The 47 enteropathogenic Escherichia coli strains isolated from the cases of infant diarrhoea were characterized from the point of view of antigenic structures and drug resistance. Six R plasmids were obtained from these strains and were tested for protective activity of E. coli K12 W 1485 against lethal action of sera. Out of three sera tested, the investigated plasmids showed the most evident protective activity upon lethal action of neonatal serum. One of the plasmids appeared even more efficient than R100.1.  相似文献   

13.
We have characterized the LEE pathogenicity islands (PAIs) of two rabbit-specific strains of enteropathogenic E. coli (REPEC), 83/39 (serotype O15:H-) and 84/110-1 (O103:H2), and have compared them to homologous loci from the human enteropathogenic and enterohaemorrhagic E. coli strains, E2348/69 and EDL933, and another REPEC strain, RDEC-1. All five PAIs contain a 34 kb core region that is highly conserved in gene order and nucleotide sequence. However, the LEE of 83/39 is significantly larger (59 540 basepairs) than those of the human strains, which are less than 44 kb, and has inserted into pheU tRNA. The regions flanking the 34 kb core of 83/39 contain homologues of two putative virulence determinants, efa1/lifA and senA. The LEE of 84/110-1 is approximately 85 kb and is located at pheV tRNA. Its core is almost identical to those of 83/39 and RDEC-1, apart from a larger espF gene, but its flanking regions contain trcA, a putative virulence determinant of EPEC. All three REPEC LEE PAIs contain a gene for an integrase, Int-phe. The LEE PAI of 84/110-1 is also flanked by short direct repeats (representing the 3'-end of pheV tRNA), suggesting that it may be unstable. To investigate this possibility, we constructed a LEE::sacB derivative of 84/110-1 and showed that the PAI was capable of spontaneous deletion. We also showed that Int-phe can mediate site-specific integration of foreign DNA at the pheU tRNA locus of E. coli DH1. Together these results indicate possible mechanisms of mobilization and integration of the LEE PAI.  相似文献   

14.
Enteropathogenic Escherichia coli may cause diarrhoea in infancy, but it is not routinely detected and regarded as a major causative agent. The aim of the present study was to estimate the incidence of enteropathogenic E. coli infection and to investigate its epidemiology and pathogenesis from faecal specimens in infants hospitalized for acute gastroenteritis. Between March 2008 and June 2009, faecal samples were collected and examined to recognize diarrhoeal aetiology, especially for E. coli, by cultural identification and multiplex-PCR. E. coli were isolated in 75 of 160 collected samples (46,88%); 10 samples of which (6,3%) had been positively recognised for pathogenic genes. Data showed that the presence of diarrheagenic E. coli infection was 6.3%, but it becomes 5% considering E. coli as a unique agent responsible for diarrhoea. The datum is not statistically meaningful because of the small sample (p>0,05). Bacterial pathogens were also isolated in 60 samples (37,5% of the total collected samples): 15 Salmonella spp., 8 Klebsiella pneumoniae, 9 Klebsiella oxytoca, 11 Citrobacter freundii, 5 Pseudomonas aeruginosa, 2 Serratia spp., 7 Enterobacter cloacae, 1 Shigella spp., 2 Campylobacter spp. Rotavirus was the predominant pathogenic single etiologic agent identified. It was found in 35 samples (21.88% of the overall collected samples), while Adenovirus, serotypes 40 or 41, was isolated in 2 samples (1.3%). Rotavirus infection was found predominantly in winter with respect to autumn. Data provide an interesting epidemiologic survey of enteropathogenic E. coli, which is not usually detected, although it may have potential clinical implications. Abbreviations: CDEC, detaching E. coli; DAEC, diffusely adherent E. coli; EAggEC, enteroaggregative E. coli; EHEC, enterohaemorrhagic E. coli; EIEC, enteroinvasive E. coli; EPEC, enteropathogenic E. coli; ETEC, enterotoxigenic E. coli.  相似文献   

15.
Antibacterial and bactericidal activities of Japanese green tea   总被引:2,自引:0,他引:2  
We found that extracts of Japanese green tea leaves inhibited the growth of various bacteria causing diarrheal diseases. All tea samples tested showed antibacterial activity against Staphylococcus aureus, S. epidermidis, Vibrio cholerae O1, V. cholerae non O1. V. parahaemolyticus, V. mimicus, Campylobacter jejuni and Plesiomonas shigelloides. None of the tea samples had any effect on the growth of V. fluvialis, Aeromonas sobria, A. hydrophila, Pseudomonas aeruginosa, Salmonella enteritidis, enteroinvasive Escherichia coli, enterohemorrhagic E. coli, enteropathogenic E. coli, enterotoxigenic E. coli, Enterobacter cloacae or Yersinia enterocolitica. Salmonella and Shigella showed susceptibilities different depending on the kind of Japanese green tea. Japanese green tea showed also bactericidal activity over S. aureus, V. parahaemolyticus and even enteropathogenic E. coli which was not sensitive when tested by cup method. The bactericidal activity was shown even at the drinking concentration in daily life.  相似文献   

16.
The consequence of harvesting young leaves of cassava as vegetable on the vulnerability of the crop to cassava mosaic disease (CMD) and on storage root yield was investigated using 30 cassava genotypes planted in IITA fields located in the humid forest (Port Harcourt?:?Onne), forest-savannah transition (Ibadan), southern guinea savannah (Mokwa) and northern guinea savannah (Zaria) agroecologies in Nigeria. Tender apical leaves and shoots of the cassava genotypes were removed from forty plants per cassava genotype with the same number of plants considered as control. Whitefly infestation, disease incidence (DI) and symptom severity (ISS) of the disease were assessed at monthly interval for six months and also at the ninth month after planting (MAP). Yield reduction due to this treatment was calculated as percentage harvest index (HI). Whitefly population fluctuated throughout the period of observation at all locations with higher population obtained generally for treated plants compared to control plants. Sprouting leaves of some treated genotypes were observed with severe mosaic symptoms, while corresponding control showed no mosaic symptoms. Contrarily, no remarkable difference was observed in Zaria between the mean ISS of treated and control cassava genotypes. There was a highly significant difference (P?<?0.01) in DI and ISS among cassava genotypes across all locations. Also, there was a highly significant interaction (P?<?0.01) in symptom severity between location (loc) and genotype, genotype and treatment (trt), loc and trt. Interaction between loc, genotypes and trt with regard to DI was highly significant at 2, 3 and 4 MAP, while with ISS, the interaction was highly significant all through the counting period. There was a positive relationship between DI and ISS on plants of genotypes 96/1039 and ISU. The percentage HI (27.4) of treated plants of genotype 95/0166 in Ibadan was remarkably lower than the value obtained for corresponding control (41.9) plants. Also, sharp distinction in% HI of treated (39.5) and control (43.8) ISU was observed in Onne with their respective ISS values as 3.7 and 3.2. Therefore, harvesting tender apical leaves and shoots of cassava as vegetables should be discouraged as it increases the severity of CMD infection in the regenerating shoots of cassava with attendant storage root yield reduction.  相似文献   

17.
Escherichia coli, including the closely related genus Shigella, is a highly diverse species in terms of genome structure. Comparative genomic hybridization (CGH) microarray analysis was used to compare the gene content of E. coli K-12 with the gene contents of pathogenic strains. Missing genes in a pathogen were detected on a microarray slide spotted with 4,071 open reading frames (ORFs) of W3110, a commonly used wild-type K-12 strain. For 22 strains subjected to the CGH microarray analyses 1,424 ORFs were found to be absent in at least one strain. The common backbone of the E. coli genome was estimated to contain about 2,800 ORFs. The mosaic distribution of absent regions indicated that the genomes of pathogenic strains were highly diversified because of insertions and deletions. Prophages, cell envelope genes, transporter genes, and regulator genes in the K-12 genome often were not present in pathogens. The gene contents of the strains tested were recognized as a matrix for a neighbor-joining analysis. The phylogenic tree obtained was consistent with the results of previous studies. However, unique relationships between enteroinvasive strains and Shigella, uropathogenic, and some enteropathogenic strains were suggested by the results of this study. The data demonstrated that the CGH microarray technique is useful not only for genomic comparisons but also for phylogenic analysis of E. coli at the strain level.  相似文献   

18.
A study on the distribution patterns of enteropathogenic bacteria polluting the shoreline in Natal, Rio Grande do Norte, Brazil, was carried out based on 72 samples obtained from three storm sewers and adjoining beach locations, Praia do Meio (PM), Areia Preta (AP) and Ponta Negra (PN). From each location, 12 water samples were taken and analyzed for fecal coliforms (FC) and Escherichia coli. In AP, two (16.7%) of the seawater samples and five (41.7%) of the storm sewer samples yielded values above 1.1 x 107 FC/100 ml, whereas only one (8.3%) of the samples from PM reached this level. There was no correlation (p > 0.05) between rainfall indices and FC values. A total of 64 E. coli isolates were obtained: 37 from the storm sewer samples and 27 from the seawater samples. Of these isolates, four (O143, two O112ac, and O124) were enteroinvasive and two (O111 and O125) were enteropathogenic. Resistance to antibiotics and to heavy metals was also analyzed. Almost 36% of the E. coli strains isolated were resistant to more than one antibiotic. All strains were resistant to zinc and copper at the highest concentration tested (250 microg/ml), and several (23.4%) were resistant to mercury at 50 microg/ml. Our results agreed with previous reports that antibiotic resistance is commonly associated with heavy-metal resistance in pathogens.  相似文献   

19.
Marking behavior, marking-like behavior [3], and changes of the scent glands were observed in aged Mongolian gerbils. In Experiment 1, changes in the marking and marking-like behavior with aging were evaluated in adult male and female Mongolian gerbils of an inbred strain aged 6 to 36 months. The frequency of marking behavior in males was significantly higher than females throughout the observation period except at 36 months of age. On the other hand, frequency of marking-like behavior in males, but not in females decreased with aging, significantly. In Experiment 2, changes of the scent gland in adult males and females aged 6 to 36 months were morphologically evaluated. Macroscopic examination revealed an increase in the size length and width of the glands of males aged 12 months and females aged 6 months. Histologically the glands of all the males and females aged 6 months developed moderately or well. Some of the 12-month-old males and females showed acinar atrophy of the glands, and all the females aged 18 months or more had highly atrophied scent glands. From these results, we concluded that there is no relationship between the changes of marking behavior and those of the scent glands in aged male Mongolian gerbils, and assume that marking behavior in aged animals does not have an important meaning as marking. In Experiment 3, marking and marking-like behavior in castrated adult Mongolian gerbils aged 16 weeks were observed. The result showed that marking behavior, not marking-like behavior was inhibited after castration. From these findings, we consider that generally marking behavior in Mongolian gerbils consists of androgen-dependent marking behavior and androgen-independent marking behavior (marking-like behavior).  相似文献   

20.
A total of 600 isolates of Escherichia coli were isolated, over a 9 month period during 1984, from healthy human adults, raw sewage and the sewage-polluted River Tigris in Nineva. Over 90% of these organisms were E. coli type 1, but only 8.3% could be serogrouped as enteropathogenic E. coli. Resistance of these organisms to 11 antimicrobial drugs was assessed. Over 40% were antibiotic-resistant and of these 77.1% were resistant to more than one antibiotic. The minimal inhibitory concentration of ampicillin for 193 selected strains from the various sources was determined and ranged from less than 0.625-greater than 160 micrograms/ml. The high incidence of antibiotic-resistant E. coli in this locality and the possible implications to human health are discussed.  相似文献   

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