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1.

Objective

The aim of this study was to determine the antimicrobial activity of amoxicillin–clavulanic acid against Escherichia coli urinary strains, especially those resistant to amoxicillin, and to analyze the results according to the susceptibility testing methods.

Method

This prospective study was made from April to May 2008, on 301 E. coli strains isolated from urine samples. The susceptibility to antibiotics was studied by agar disk diffusion according to French Society of Microbiology Antibiogram Committee recommendations. MIC were determined with the E-test.

Results

According to the antibiogram, 59.8% of strains were resistant to amoxicillin, 33.2% to amoxicillin–clavulanic acid, 1.7% to cefotaxim, 8.3% to nalidixic acid, 6.6% to ofloxacin, 4.7% to ciprofloxacin, 4.7% to gentamicin and 38.1% to cotrimoxazole. After determining the MIC of E. coli strains resistant to amoxicillin and susceptible to amoxicillin–clavulanic acid, 37.5% (n = 30) remained susceptible, 61.25% (n = 55) were of intermediate susceptibility and only one strain (1.25%) was resistant.Among E. coli strains resistant to amoxicillin and intermediately susceptible to amoxicillin–clavulanic acid, 83.3% (n = 55) remained intermediately susceptible, 13.7% (n = 9) became susceptible and two strains (3%) were resistant.

Conclusion

The susceptibility testing methods, especially for amoxicillin–clavulanic acid, must be standardized to avoid the discrepancies noted between standard antibiograms and an accurate determination of MIC.  相似文献   

2.
3.
Evidence is mounting that microorganisms originating from livestock impact the air quality of the animal houses themselves and the public in the surrounding neighborhoods. The aim of this study was to develop efficient bacterial source tracking capabilities to identify sources of Escherichia coli aerosol pollution caused by pigs. Airborne E. coli were isolated from indoor air, upwind air (10 and 50 m away) and downwind air samples (10, 50, 100, 200 and 400 m away) for five swine houses using six-stage Andersen microbial samplers and Reuter-Centrifugal samplers (RCS). E. coli strains from pig fecal samples were also collected simultaneously. The enterobacterial repetitive intergenic consensus polymerize chain reaction (ERIC-PCR) and the repetitive extragenic palindromic (REP-PCR) approaches were used to study the genetic variability and to determine the strain relationships among E. coli isolated from different sites in each swine house. Results showed that 35.1% (20/57) of the bacterial DNA fingerprints from the fecal isolates matched with the corresponding strains isolated from indoor and downwind air samples (similarity ?90%). E. coli strains from the indoor and downwind air samples were closely related to the E. coli strains isolated from feces, while those isolated from upwind air samples (swine house C) had low similarity (61-69%). Our results suggest that some strains isolated from downwind and indoor air originated in the swine feces. Effective hygienic measures should be taken in animal farms to prevent or minimize the downwind spread of microorganism aerosol.  相似文献   

4.

Objectives

This study aimed to investigate the prevalence of antibiotic resistance in fecal Escherichia coli isolates from healthy persons and patients with diarrhea.

Methods

E. coli isolates (n = 428) were obtained from fecal samples of apparently healthy volunteers and hospitalized patients with diarrhea. Susceptibility patterns of isolates to 16 antimicrobial agents were determined by agar disc diffusion.

Results

Most E. coli isolates exhibited less than 10% resistance against imipenem, cefotetan, aztreonam, cefepime, cefoxitin, amikacin and netilamicin, although greater than 65% were resistant to ampicillin and tetracycline. No significant difference in resistance rates for all tested antibiotics was found between isolates from the healthy-and diarrheal-patient groups, including for multi-drug resistance (p = 0.22). The highest number of resistant antibiotics was 12 antibiotics. No significant differences in antibiotic resistance were found among the sex and age strata for isolates from healthy individuals. However, antibiotic resistance rates to cefoxitin, cefotaxime, amikacin, and netilamicin were significantly higher in the isolates of men than those of women (p < 0.05) in isolates from patients with diarrhea. Furthermore, isolates from patients with diarrhea older than 40-years of age showed higher resistance to cefepime and aztreonam (p < 0.05).

Conclusion

High resistance to the antibiotics most frequently prescribed for diarrhea was found in isolates from patients with diarrhea and apparently healthy individuals without any significant difference.  相似文献   

5.
In this paired case-control study of infants with diarrhea in São Paulo, we examined the association between HEp-2–adherent Escherichia coli strains and diarrhea. We tested isolates from stool specimens of infants with diarrhea and matched controls in an HEp-2 cell adherence assay; we then hybridized isolates with DNA probes and identified enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), and diffusely adherent E. coli (DAEC). From 100 patient-control pairs, we isolated 78 HEp-2–adherent strains; of these, 61 strains were single pathogens identified in stools of infants with diarrhea. While typical EPEC was significantly associated with diarrhea (p<0.001), EAEC was more frequently associated with diarrhea in clinical cases (20%) compared with healthy controls (3%) (p<0.001). Atypical EPEC, showing a localized adherence-like pattern, was also more common in patients than controls (p>0.1). DAEC was isolated with equal frequency from patients and controls (p>0.1).  相似文献   

6.
Volunteer challenge with enterotoxigenic Escherichia coli (ETEC) has been used for four decades to elucidate the pathogenesis and immune responses and assess efficacy of various interventions. We performed a systematic review of these studies and a meta-analysis of individual patient-level data (IPD) from a subset of studies using standard methodology.We identified 27 studies of 11 ETEC strains administered to 443 naive subjects at doses from 1 × 106 to 1 × 1010 colony forming units (cfu). Diarrhea attack rates varied by strain, dose and enterotoxin. Similar rates were seen at doses of 5 × 108 to 1 × 1010 cfu with the three most commonly used strains B7A, E24377A, H10407. In IPD analysis, the highest diarrhea attack rates were seen with strains B7A, H10407 and E24377A. The H10407 induced significantly higher stool output than the other strains. Additionally, the rate of output was different across strains.The risk of diarrhea, abdominal cramps, nausea and headaches differed significantly by ETEC strain. An increased risk of nausea, abdominal cramps and headaches was seen for females. Baseline anti-LT IgG titers appeared to be associated with a decrease risk of diarrhea outcomes, a trend not seen with anti-LT IgA or seen consistently with anti-colonization factor antibodies. Neither early antibiotic treatment nor diarrhea duration significantly affected the frequency or magnitude of serologic responses.These studies have served as an invaluable tool in understanding disease course, pathogenicity, innate immune responses and an early assessment of product efficacy. When designing and planning experimental ETEC infection studies in this age of increased ethical scrutiny and growing appreciation of post-infectious sequelae, better understanding of available data is essential.  相似文献   

7.
Prevalence, incidence and seasonal variation of Cryptosporidium and Giardia duodenalis were studied over a 12-month period in 100 children from four pre-schools in Kafue, Zambia. Questionnaire data and a single stool sample were collected monthly from each child. Samples were processed using a commercial kit (Meridian Diagnostics Inc., USA) and oo(cysts) visualised by immunofluorescence microscopy. Cryptosporidium was detected in 30.7% (241/786; 95% CI = 27.5-33.9) while G. duodenalis was detected in 29.0% (228/786; 95% CI = 25.8-32.2). A total of 86% experienced one or more episodes of cryptosporidiosis while 75% had giardiasis. Cumulative incidence per 100 children was 75.4 for Cryptosporidium and 49.0 for G. duodenalis. Both infections were significantly more common in the wet compared to the dry season (34.8%, 162/466 vs. 24.7%, 79/320, P = 0.003 and 35.2%, 164/466 vs. 20.0%, 64/320, P < 0.001, respectively). Thus, risk ratios (RR) were 1.41 (95% CI = 1.13-1.77) and 1.76 (95% CI = 1.38-2.27) for Cryptosporidium and Giardia, respectively. Diarrhoea was significantly associated with cryptosporidiosis (RR = 1.23, 95% CI = 1.03-1.47; P = 0.029) but not with giardiasis (RR = 1.12, 95% CI = 0.91-1.53; P = 0.26). We conclude that gastro-intestinal protozoal infections are highly prevalent among children attending pre-school in peri-urban Zambia highlighting the need for further studies of risk factors.  相似文献   

8.

Background

In Switzerland, the heptavalent (PCV7) and 13-valent pneumococcal conjugate vaccine (PCV13) were recommended for all infants aged <2 years in 2007 and 2011, respectively. Due to herd effects, a protective impact on the invasive pneumococcal disease (IPD) rates in adults had been expected.

Methods

Within this study, data from the nationwide mandatory surveillance was analyzed for all adult patients ≥16 years with IPD of known serotype/serogroup during 2003–2012. Trend (for IPD cases from 2003 to 2012) and logistic regression analyses (2007–2010) were performed to identify changes in serotype distribution and to identify the association of serotypes with age, clinical manifestations, comorbidities and case fatality, respectively.

Findings

The proportion of PCV7 serotypes among all IPD cases (n = 7678) significantly declined in adults from 44.7% (2003) before to 16.7% (2012) after the recommendation of PCV7 (P < 0.001). In contrast, the proportion of non-PCV7 serogroup/serotypes increased for non-PCV13 but also PCV13 serotypes (not included in PCV7) at the same time. Serotype distribution varied significantly across ages, clinical manifestations and comorbidities. Serotype was furthermore associated with case fatality (P = 0.001). In a multivariable logistic regression model, analyzing single serotypes showed that case-fatality was increased for the serotypes 3 (P = 0.008), 19A (P = 0.03) and 19F (P = 0.005), compared to serotype 1 and 7F.

Conclusion

There was a significant decline in PCV7 serotypes among adults with IPD in Switzerland after introduction of childhood vaccination with PCV7. Pneumococcal serotypes were associated with case fatality, age, clinical manifestation and comorbidities of IPD in adults. These results may prove useful for future vaccine recommendations for adults in Switzerland.  相似文献   

9.
It is well-known that metabolism of benzene is required for the induction of toxicity and consequent health problems. Therefore, genetic variation in benzene (BZ) metabolism genes can influence health outcomes. However, large population studies are needed to provide more evidence for such relationship. We have conducted a large population investigation (385 BZ-exposed shoe workers and 197 matched healthy controls) on the association between inheritance of certain BZ metabolizing genes and the expression of micronuclei (MN). The latter was based on the cytokinesis-blocked MN assay. We analyzed the polymorphisms of GSTM1, GSTT1, GSTP1 (rs1695), CYP2E1 (rs3813867), CYP2E1 (rs2031920), CYP2E1 (rs6413432), mEH exon 3 (rs1051740), mEH exon 4 (rs2234922). Univariate Poisson regression analysis demonstrated that the BZ-exposed workers had significantly increased MN frequency compared with the controls (FR = 1.84, 95% CI: 1.56–2.18; P < 0.001), and showed a cumulative exposure dose–response relationship. The CYP2E1 rs3813867 mutant allele (CC + GC) (FR 1.15, 95% CI 1.02–1.29; P = 0.020) and rs2031920 variant allele (CT + TT) (FR = 1.23, 95% CI: 1.09–1.37, P < 0.01) was associated with higher MN frequency significantly compared with the wild genotype separately. Furthermore, the MN frequency in rs2031920 variant allele (CT + TT) (FR = 1.17, 95% CI: 1.04–1.31, P < 0.01) was also higher than the wild genotype when the age, gender and cumulative exposure dose was adjusted in Poisson regression. In addition, the CYP2E1, however, GSTM1null, GSTT1null, GSTP1 rs1695, rs6413432, rs1051740 and rs2234922 polymorphisms showed no association with MN frequency. Our results indicate that two promoter polymorphisms in the CYP2E1 gene, especially the rs2031920 variant allele, were involved with the BZ-induction of MN and may contribute to risk of cancer among exposed workers.  相似文献   

10.

Objectives

We had for objective to measure the incidence and the clonal diversity of Escherichia coli and Klebsiella pneumoniae producing extended-spectrum β-lactamases (ESBL) in order to assess the role of patient stay in amplification of the phenomenon, in our teaching hospital.

Material and methods

We measured the quarterly incidence rates of E. coli and K. pneumoniae producing or not producing ESBL in clinical samples between 1999 and 2010. The incidence of ESBL-producing isolates was season-adjusted. We determined the pulsotype of and identified the ESBL in all non-redundant strains isolated between 2009 and 2010.

Results

The incidence for 1000 hospitalization days increased from 0.00 to 0.44 for ESBL-producing E. coli, from 0.012 to 0.24 for ESBL-producing K. pneumoniae, from 1999 to 2010. Fifty-three different clones of E. coli were identified among the 61 genotyped isolates. The 28 K. pneumoniae isolates genotyped clustered into 11 different clones, among which one major epidemic clone that included 18 isolates. Respectively 66 and 75% of E. coli and K. pneumoniae isolates produced a CTX-M group 1 ESBL.

Conclusion

The hospital seems to play a different role in the amplification of ESBL according to the producing species (K. pneumoniae or E. coli). ESBL-producing E. coli seem to have a limited cross-transmission within the hospital and seem to be added to non-producers. Conversely, ESBL-producing K. pneumoniae seem to be cross-transmitted within the hospital and to replace non-producers.  相似文献   

11.
Plasmid-based vaccines and therapeutics have been making their way into the clinic in the last years. The existence of cost-effective manufacturing processes capable of delivering high amounts of high-quality plasmid DNA (pDNA) is essential to generate enough material for trials and support future commercialization. However, the development of pDNA manufacturing processes is often hampered by difficulties in predicting process scale performance of Escherichia coli cultivation on the basis of results obtained at lab scale. This paper reports on the differences observed in pDNA production when using shake flask and bench-scale bioreactor cultivation of E. coli strains MG1655ΔendAΔrecA and DH5α in complex media with 20 g/L of glucose. MG1655ΔendAΔrecA produced 5-fold more pDNA (9.8 mg/g DCW) in bioreactor than in shake flask (1.9 mg/g DCW) and DH5α produced 4-fold more pDNA (8 mg/g DCW) in bioreactor than in shake flask (2 mg/g DCW). Accumulation of acetate was also significant in shake flasks but not in bioreactors, a fact that was attributed to a lack of control of pH.  相似文献   

12.
Shiga toxin-producing Escherichia coli (STEC) causes worldwide outbreaks of food and waterborne diseases. Rapid identification of causative agents is critical for early intervention in the case of widespread diarrheal epidemics to prevent mortality. In this study, a Molecular-Beacon targeting stx2 gene (highly associated with human illness) was designed to develop a culture-independent real-time PCR assay for detection and quantification of STEC in water samples. The assay could detect lowest 10 genomic equivalent (GE) of the reference strain (E. coli I.T.R.C.-18) per PCR or 100 GE/mL. The presence of 106 CFU/mL of non-pathogenic E. coli DH5α has no impact on sensitivity of the assay. The assay could successfully enumerate STEC in surface water (collected from a sewage impacted river) and potable water samples collected from Lucknow city without prior enrichment. The assay will be useful in pre-emptive monitoring of surface/potable waters to prevent waterborne outbreaks caused by STEC.  相似文献   

13.
Ho PL  Chiu SS  Ang I  Lau YL 《Vaccine》2011,29(17):3270-3275
This study analyzed 828 isolates causing invasive pneumococcal disease (IPD) before (1995-2001, n = 265) and after (2007-2009, n = 563) the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in Hong Kong. In children <5 years, serotype 14 had declined (36-15.7%, P < 0.01) while 19A had increased (0-12.9%, P < 0.01) in the before and after periods, respectively. In children aged <5 years, the proportion of PCV7 serotypes declined from 89.5% to 65.7% (72.8% if included cross protection against 6A) with time but that of PCV13 serotypes remained stable (91.4-93.2%). In elderly ≥65 years, 9V and 23F decreased from 3.8% to 0.3% (P = 0.01) and from 18.9% to 7.4% (P <0.01), respectively while 7F increased significantly from 0% to 4.1% (P = 0.04) over the same periods. Among isolates from aged <5 years, dual penicillin/erythromycin resistance increased from 44.1% to 64.2% (P = 0.01). The types that often had dual penicillin/erythromycin resistance were 6B, 14, 19F, 23F, 6A and 19A. The emergence of serotype 19A was associated with expansion of sequence type 320.  相似文献   

14.
目的 基于临床医院开展4种致泻性大肠埃希菌(DEC)人群监测,探讨公共卫生实验室对临床实验室需求的直接技术指导的实践模式。方法 设立哨点医院,以标准化方法筛选和鉴定DEC菌型;构建DEC流行特征基线;对疑似暴发病例开展基于实验室和流行病学调查。结果 2012-2013年选择上海地区4家哨点医院检测7 204份腹泻标本确认的712例DEC感染病例,阳性率为9.9%。其中肠致病性大肠埃希菌(EPEC)感染351例;肠产毒性大肠埃希菌(ETEC)感染292例;肠侵袭性大肠埃希菌(EIEC)感染32例;产志贺样毒素大肠埃希菌(STEC/EHEC)感染6例;DEC混合感染31例。EPEC感染以1~5岁儿童最多见,菌型均为aEPEC;ETEC流行峰值在8月,阳性率>20%,感染病例2012年聚集于1~28日龄和2013年的20~60岁人群(P< 0.05),菌型以耐热肠毒素(ST)型最多(59.6%),其次为不耐热肠毒素(LT)型(27.8%)和ST/LT型(12.6%);2013年儿童感染EIEC病例明显增加(P< 0.01);未监测到EHEC O157 : H7,但确认2例EHEC O26 : H11(eae-hlyA-stx1a)儿童病例;调查确认2012年上海地区15例新生儿ETEC聚集性感染病例与四川省自贡市新生儿病例属于同一克隆(STh-CS21-CFA/I-ClyA-EatA-ST2332- SHNL0005)。结论 上海地区DEC型谱特征已发生改变,ETEC对新生儿院内感染和食源性感染性腹泻构成潜在暴发风险,需加强实验室主动监测。  相似文献   

15.

Introduction

An outbreak of shiga-toxin producing Escherichia coli infections occurred in southwest France in June 2012. The outbreak was investigated to identify the source of infection, and guide control measures.

Methods

Confirmed outbreak cases were patients who developed bloody diarrhoea or haemolytic uremic syndrome (HUS) between 28 May and 6 July 2012, with E. coli O157 isolates showing indistinguishable patterns on pulse field gel electrophoresis (PFGE). A standardized questionnaire was administered to patients to document food consumption and other risk exposures. Their purchase was checked through their supermarket shopper card data.

Results

Six patients (four with HUS and two with bloody diarrhea) were confirmed outbreak cases. Fresh ground beef burgers from one supermarket were the only common food exposure, identified by interviews and shopper card data. The PFGE profile of shiga toxin-producing E. coli O157 isolated from the suspected beef burgers was identical to those from the human cases. The suspected beef burgers were no longer on sale at the time of investigation but three patients confirmed as outbreak cases had deep-frozen some at home.

Conclusion

Shopper card data was particularly useful to obtain precise and reliable information on the traceability of consumed food. Despite the expired use-by date, a recall was issued for the beef burgers. This contributed to preventing other cases among consumers who had deep-frozen the beef burgers.  相似文献   

16.

Objectives

To investigated whether the CTX-M-14 gene could be transferred from a clinical Shigella sonnei strain to commensal Escherichia coli strain in the gastroenteritis microbiome.

Methods

E. coli strains were isolated from 30 stool samples of S. sonnei infected students in a gastroenteritis outbreak in 2004 and were characterized by antibiotic resistance analysis, in vitro conjugation and in vivo transfer of CTX-M-14 gene and molecular assays.

Results

One strain of Escherichia coli that had high levels of resistance to cefotaxime was isolated from a patient infected with S. sonnei. Isoelectric focusing showed that the E. coli and S. sonnei strains produced a β-lactamase with an isoelectric point of 8.1. Moreover, polymerase chain reaction analysis indicated that both strains possessed the same DNA sequences for CTX-M-14. The results of in vitro and in vivo conjugation showed that the efficiency of CTX-M-14 transfer from S. sonnei to E. coli was similar to CTX-M-14 transfer between E. coli strains.

Conclusion

The data suggest that the acquisition of the extended-spectrum β-lactamases gene by pathogenic bacteria in the human intestinal tract to commensal microbiome bacteria can cause serious infectious diseases.  相似文献   

17.
APOBEC3B, a gene involved in innate response, exhibits insertion-deletion polymorphism across world populations. We observed the insertion allele to be nearly fixed in malaria endemic regions of sub-Saharan Africa as well as populations with high malaria incidence in the past. This prompted us to investigate the possible association of the polymorphism with falciparum malaria. We studied the distribution of APOBEC3B, in 25 diverse Indian populations comprising of 500 samples and 176 severe or non-severe Plasmodium falciparum patients and 174 ethnically-matched uninfected individuals from a P. falciparum endemic and a non-endemic region of India. The deletion frequencies ranged from 0% to 43% in the Indian populations. The frequency of the insertion allele strikingly correlated with the endemicity map of P. falciparum malaria in India. A strong association of the deletion allele with susceptibility to falciparum malaria in the endemic region (non-severe vs. control, Odds ratio = 4.96, P value = 9.5E−06; severe vs. control, OR = 4.36, P value = 5.76E−05) was observed. Although the frequency of deletion allele was higher in the non-endemic region, there was a significant association of the homozygous deletion genotype with malaria (OR = 3.17, 95% CI = 1.10-10.32, P value = 0.0177). Our study also presents a case for malaria as a positive selection force for the APOBEC3B insertion and suggests a major role for this gene in innate immunity against malaria.  相似文献   

18.
In May 2011 one of the worldwide largest outbreaks of haemolytic uraemic syndrome (HUS) and bloody diarrhoea caused by Shiga toxin-producing Escherichia coli (STEC) serotype O104:H4 occurred in Germany. One of the most affected federal states was Lower Saxony. We present the investigation of a cluster of STEC and HUS cases within this outbreak by means of a retrospective cohort study. After a 70th birthday celebration which took place on 7th of May 2011 among 72 attendants seven confirmed cases and four probable cases were identified, two of them developed HUS. Median incubation period was 10 days. Only 35 persons (48.6%) definitely answered the question whether they had eaten the sprouts that were used for garnishing the salad. Univariable analysis revealed different food items, depending on the case definition, with Odds Ratio (OR) > 1 indicating an association with STEC infection, but multivariable logistic regression showed no increased risk for STEC infection for any food item and any case definition. Sprouts as the source for the infection had to be assumed based on the results of a tracing back of the delivery ways from the catering company to the sprouts producer who was finally identified as the source of the entire German outbreak. In this large outbreak several case–control studies failed to identify the source of infection.  相似文献   

19.
Enterotoxemia, a disease that affects domestic ruminants, is caused mainly by the epsilon toxin from Clostridium perfringens type D. Its eradication is virtually impossible, control and prophylaxis are based on systematic vaccination of herds with epsilon toxoids that are efficient in inducing protective antibody production. The use of recombinant toxins is one of the most promising of these strategies. This work evaluates the potency of a Cl. perfringens type D epsilon toxoid expressed by Escherichia coli administered to goats, sheep, and cattle. The etx gene was cloned into the pET-11a plasmid of E. coli strain BL21 to produce the recombinant toxin. Rabbits (n = 8), goats, sheep, and cattle (n = 5 for each species) were immunized with 0.2 mg of the insoluble recombinant protein fraction to evaluate vaccine potency of the epsilon toxoid studied. Antibody titers were 40, 14.3, 26, and 13.1 IU/mL in the rabbit, goat, sheep, and cattle serum pools, respectively. The epsilon toxoid produced and tested in this work is adequate for immunization of ruminants against enterotoxemia.  相似文献   

20.
Alberta, Canada introduced the Streptococcus pneumoniae seven valent conjugate vaccine (PCV7) program for children less than 2 years of age in September 2002. We determined the rates of invasive pneumococcal disease in Alberta, Canada 2 years pre- and 4 years post-PCV7 introduction (2000–2006) as well as the rates of antibiotic resistance and serotype distribution in this same time period. Overall, PCV7 serotypes decreased 61% from 2000 to 2006. The greatest decrease in incidence of invasive pneumococcal disease occurred in children less than 2 years of age declining from a high of 96.7/100,000 (2000) to 25.8/100,000 (2006) (P < 0.0001). Non-susceptibility of S. pneumoniae isolates to penicillin dropped significantly from 14% in 2000 to 4.6% in 2006 (P < 0.0001). Non-susceptible erythromycin isolates also decreased from 8.8% (2000) to 5.8% (2006) (= 0.13).  相似文献   

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