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1.

Background

Rhodococcus equi is a recognized cause of disease in humans, especially in individuals who are immunocompromised. Because diphtheroids are regarded as part of normal respiratory flora, the importance of R. equi as a pulmonary pathogen may not be fully appreciated and its prevalence may be underestimated. Most treatment recommendations for R. equi infection were established before antiretroviral drugs became available for human immunodeficiency virus/AIDS therapy, and therapeutic strategies may need to be updated.

Objectives

To review the role of R. equi as a cause of pulmonary infection; to highlight its importance for clinicians and microbiologists; and to challenge current approaches to treatment, whether in immunodeficient or immunocompetent individuals.

Sources

A PubMed search using combinations of the following terms: ‘Rhodococcus (automatically including Corynebacterium) equi’ AND ‘pneumonia’ OR ‘pulmonary’ infection, then cross-checking references in the resulting cases, case series and reviews.

Content

We provide a review that details the challenges in the diagnosis, microbiology and pathogenesis of pulmonary infection caused by R. equi and the options for treatment.

Implications

Ten to 14 days of treatment may be effective for pneumonia due to R. equi. Our review suggests that longer courses of therapy are needed for cavitary lesions and lung masses. However, recommendations for excessively prolonged treatment of all pulmonary infections arose during a time when many cases occurred in individuals with AIDS and before effective antiretroviral therapy was available. We suggest that the rationale for prolonged therapy with multiple antibiotics needs to be re-evaluated.  相似文献   

2.

Objectives

: To compare the discriminatory capacity of the quick sequential organ failure assessment (qSOFA) vs. the systemic inflammatory response syndrome (SIRS) score for predicting 30-day mortality and intensive care unit (ICU) admission in patients with suspicion of infection at an HIV reference centre.

Methods

We performed a prospective cohort study including consecutive adult patients who had suspected infection and who were subsequently admitted to the medical ward. Variables related to qSOFA and SIRS were measured at admission. The performance (area under the receiver operating curve, AUROC) of qSOFA (score ≥2) and SIRS (≥2 criteria) as a predictor of 30-day mortality and ICU admission was evaluated.

Results

One hundred seventy-three patients (mean ± standard deviation age, 42.6 ± 12.4 years) were included in the analysis; 107 (61.8%) were male, and 111 (64.2%) were HIV positive. Respiratory and gastrointestinal infections occurred in 49 (28.3%) and 23 (13.3%), respectively. The 30-day mortality rate was 9 (5.2%) of 173. The prognostic performance of qSOFA was similar compared to SIRS, with an AUROC of 0.68 (95% confidence interval, 0.55–0.81) and 0.69 (95% confidence interval, 0.53–0.86) (p 0.96). Twenty patients (11%) were admitted to the ICU; qSOFA and SIRS had a similar discriminatory capacity for ICU admission (AUROC 0.63 (95% confidence interval, 0.51–0.75) and 0.63 (95% confidence interval, 0.50–0.76)), respectively).

Conclusions

We found a poor prognostic accuracy of the qSOFA to predict 30-day mortality in hospitalized patients suspected of infection in a setting with a high burden of HIV infection.  相似文献   

3.
4.

Objectives

Our objective was to evaluate factors associated with recurrence in patients with 027+ and 027– Clostridium difficile infection (CDI).

Methods

Patients with CDI observed between January and December 2014 in six hospitals were consecutively included in the study. The 027 ribotype was deduced by the presence of tcdB, tcdB, cdt genes and the deletion Δ117 in tcdC (Xpert® C. difficile/Epi). Recurrence was defined as a positive laboratory test result for C. difficile more than 14 days but within 8 weeks after the initial diagnosis date with reappearance of symptoms. To identify factors associated with recurrence in 027+ and 027– CDI, a multivariate analysis was performed in each patient group. Subdistributional hazard ratios (sHRs) and 95% confidence intervals (95%CIs) were calculated.

Results

Overall, 238 patients with 027+ CDI and 267 with 027– CDI were analysed. On multivariate analysis metronidazole monotherapy (sHR 2.380, 95%CI 1.549–3.60, p <0.001) and immunosuppressive treatment (sHR 3.116, 95%CI 1.906–5.090, p <0.001) were factors associated with recurrence in patients with 027+ CDI. In this patient group, metronidazole monotherapy was independently associated with recurrence in both mild/moderate (sHR 1.894, 95%CI 1.051–3.410, p 0.033) and severe CDI (sHR 2.476, 95%CI 1.281–4.790, p 0.007). Conversely, non-severe disease (sHR 3.704, 95%CI 1.437–9.524, p 0.007) and absence of chronic renal failure (sHR 16.129, 95%CI 2.155–125.000, p 0.007) were associated with recurrence in 027– CDI.

Conclusions

Compared to vancomycin, metronidazole monotherapy appears less effective in curing CDI without relapse in the 027+ patient group, independently of disease severity.  相似文献   

5.

Objectives

To analyse genomic sequence data of referred Streptococcus pyogenes isolates and those pertaining to selected elderly/nursing care or maternity clusters from 2010 to 2015 to ascertain genomic differences between epidemiologically related isolates and unrelated isolates from outbreaks of disease.

Methods

The genomic sequences of 134 S. pyogenes isolates from 21 clusters of infection in elderly care or maternity settings from 2010 to 2015 were analysed using bioinformatics to ascertain genomic phylogeny, single nucleotide polymorphism (SNP) differences and statistical outliers from epidemiologically defined outbreaks. Analysis was undertaken within clusters and compared with sporadic isolates from geographically distinct outbreaks of S. pyogenes infection.

Results

Genomic sequence analysis of 21 outbreaks of S. pyogenes infection ranged in size from a single patient (with colonized healthcare worker link) to 18 patient cases of group A streptococcus (GAS) infection in a single setting. Seventeen healthcare workers were identified in 8 of 21 outbreaks with the associated outbreak strain, with multiple staff in 2 of 21 outbreaks. Genomic sequences from epidemiologically linked isolates from patients, staff and healthcare environmental settings were highly conserved, differing by 0–1 SNP in some cases and mirrored geographical data. Four of 21 outbreaks had environmental contamination with the outbreak strain, indistinguishable or of limited SNP difference to the patient isolates. Genomic SNP analysis enabled exclusion of ten isolates from epidemiological outbreaks.

Conclusions

Genomic discrimination can be applied to assist outbreak investigation. It enabled confirmation or exclusion of GAS cases from epidemiologically defined outbreaks. Colonization of healthcare workers and environmental contamination with the outbreak strain was demonstrated for several outbreaks.  相似文献   

6.

Objectives

Prediction of embolic events (EEs) in infective endocarditis (IE) could inform clinical decisions, such as surgical timing. We conducted a systematic review to more precisely define associations between risk factors and EEs.

Methods

We searched two bibliographic databases (1994–2018) for observational studies that reported EEs in IE patients and considered clinical, microbiological or echocardiographic risk factors. Studies that did not use Duke criteria or only investigated a subset of IE patients were excluded. Study quality was assessed using the Newcastle–Ottawa scale. A pooled risk ratio (RR) for each risk factor was estimated using random-effects models; statistical heterogeneity was estimated using I2.

Results

Of 3862 unique citations, 47 cohort studies (11 215 IE cases) were included; 54 risk factors were analysed in at least two studies, with nine studies reporting other individual factors. Most studies were of high methodological quality. Major predictors of EEs were intravenous drug use (RR 1.69, 95% CI 1.32–2.17; I2 = 46%), Staphylococcus aureus infection (RR 1.64, 95% CI 1.45–1.86, I2 = 32%), mitral valve vegetation (RR 1.24, 95% CI 1.11–1.37, I2 = 30%), and vegetation size >10 mm (RR 1.87, 95% CI 1.57–2.21, I2 = 48%). EE risk was also higher with human immunodeficiency virus, chronic liver disease, elevated C-reactive protein, Staphylococcus spp. infection, vegetation presence, and multiple, mobile or prosthetic mechanical valve vegetation, and lower with Streptococcus spp. infection. Most findings were unchanged in sensitivity analyses that removed studies with pulmonary EEs from the outcome.

Conclusions

Given the serious consequences of embolism, surgical evaluation may be considered in patients with these risk factors.  相似文献   

7.

Background

The clinical features and outcomes of cytomegalovirus (CMV) diseases in patients with systemic lupus erythematosus (SLE) are unknown. We analyzed such data from a medical center in Taiwan.

Methods

We retrospectively reviewed the medical records of patients with SLE who were diagnosed with CMV diseases between 2006 and 2016 in Taipei Veterans General Hospital Taiwan. Clinical and laboratory parameters and treatment outcomes were analyzed.

Results

The study enrolled 56 eligible patients with CMV diseases and separated them into survival (n = 24) and mortality (n = 32) groups. All cases showed a significantly high incidence of pneumonitis (71.43%). The patients in the mortality group had a higher SLE disease activity index (SLEDAI)-2000 (p = 0.009), more cases of recent methylprednisolone pulse therapy (p = 0.013) and pancytopenia (p = 0.001), stronger evidence of CMV infection demonstrated by polymerase chain reaction (PCR) in blood (p < 0.001) and bronchoalveolar lavage (p = 0.021), and more concurrent infections (bacteremia p = 0.026; fungemia p < 0.001).

Conclusions

Recent pulse therapy, pancytopenia, and concurrent infections constituted risk factors for mortality in patients with SLE and CMV infection. Among mortality patients, PCR rather than serological tests (IgM antibodies) helped to arrive at an earlier diagnosis.  相似文献   

8.

Objectives

To determine MIC distributions for Mycobacterium chimaera, Mycobacterium intracellulare, Mycobacterium colombiense and Mycobacterium avium, and to derive tentative epidemiological cut-off (ECOFF) values.

Methods

A total of 683 bacterial isolates (M. chimaera, n = 203; M. intracellulare, n = 77; M. colombiense, n = 68; M. avium, n = 335) from 627 patients were tested by broth microdilution according to CLSI protocol M24-A2 on Sensititre RAPMYCOI plates. MICs were interpreted based on CLSI breakpoints for clarithromycin, and tentative breakpoints for amikacin, moxifloxacin and linezolid. Tentative ECOFFs were determined by visual approximation and the ECOFFinder algorithm.

Results

Modal MIC, MIC50 and MIC90 values were within ± one dilution step from the respective aggregated data set for 47/48 (97.9%), 48/48 (100%) and 48/48 (100%) species–drug combinations. Clarithromycin wild-type populations were mostly classified as susceptible (MIC90 4–8 mg/L; S ≤8 mg/L). Rifabutin MICs were lower than those of rifampicin. Tentative moxifloxacin, linezolid and amikacin breakpoints split wild-type populations. No ECOFFs could be set for rifampicin, ethambutol, ciprofloxacin, isoniazid, trimethoprim/sulfamethoxazole and doxycycline because of truncation of MIC distributions. Agreement between the visually determined and the modelled 97.5% ECOFFs was 90.9%. All 99.0% ECOFFs were one titre step higher than by visual approximation.

Conclusions

Drug susceptibility patterns of M. chimaera are comparable to those of closely related species. Except for clarithromycin, breakpoints for Mycobacterium avium-intracellulare complex should be re-evaluated. Statistical determination of the 99.0% ECOFF may be superior to visual approximation.  相似文献   

9.

Background/Purpose

To investigate the clinical characteristics and pathogens of community-onset bacteremia among human immunodeficiency virus (HIV)-infected adults as well as to establish the clinical predictors of the major microorganisms.

Methods

An observational cohort study was conducted retrospectively between January 2007 and December 2012. Demographic characteristics and pathogens determined from chart records were analyzed.

Results

Of the 121 eligible HIV adults with bacteremia, there was a male predominance (106 patients, 87.6%); elderly individuals (age ≥ 65 years) accounted for only 2.5% of the study population (3 patients). Of the total microorganisms isolated (n = 123), Staphylococcus aureus (55, 44.7%) and Salmonella enterica (17, 13.8%) were the common pathogens. In a multivariate analysis, the leading two significant predictors of S. aureus infection were infective endocarditis (odds ratio, 11.49; p = 0.001) and transmission risk with injection drug users (IDUs; odds ratio, 6.22; p = 0.001). In addition, transmission risk with men who have sex with men (MSM; odds ratio, 37.49; p = 0.001) was the leading clinical predictor of S. enterica infection. In further analyses, a strong linear-by-linear correlation between S. aureus infection and IDU (γ = 0.94, p = 0.02) as well as between S. enterica infection and MSM (γ = 0.96, p = 0.01) was evidenced.

Conclusion

Focusing on the two key pathogens in HIV-infected adults with community-onset bacteremia, IDU was one of independent predictors associated with S. aureus infection, whereas MSM was the leading risk factor of S. enterica infection. Although the proposed predictive model of these pathogens has been not established, a scoring system involving the transmission risk of HIV may be of use for the early identification of these patients for clinicians.  相似文献   

10.

Background/purpose

The clinical manifestations of scrub typhus, murine typhus and acute Q fever in the elderly are not clear.

Methods

We conducted a retrospective study to identify the characteristics of the elderly aged ≥65 years with a comparison group aged 18–64 years among patients with scrub typhus, murine typhus, or acute Q fever who were serologically confirmed at three hospitals in Taiwan during 2002–2011.

Results

Among 441 cases, including 187 cases of scrub typhus, 166 acute Q fever, and 88 murine typhus, 68 (15.4%) cases were elderly patients. The elderly had a higher severe complication rate (10.3% vs. 3.5%, p = 0.022), but did not have a significantly higher mortality rate (1.47% vs. 0.54%, p = 0.396). Compared with those without severe complications, we found the elderly (p = 0.022), dyspnea (p = 0.006), less relative bradycardia (p = 0.004), less febrile illness (p = 0.004), prolonged prothrombin time (PT) (p = 0.002), higher levels of initial C-reactive protein (p = 0.039), blood leukocyte counts (p = 0.01), and lower platelet counts (p = 0.012) are significantly associated with severe complications. Only prolonged prothrombin time was associated with severe complications in multivariate analysis (p = 0.018, CI 95% 0.01–0.66). Among clinical symptoms and laboratory data, multivariate analysis revealed chills was less frequently occurred in the elderly (p = 0.012, 95% confidence interval [CI]: 1.33–9.99).

Conclusion

The elderly cases with scrub typhus, murine typhus, or acute Q fever would be more likely to have severe complications, for which prothrombin time prolongation is an important predictor for severe complications.  相似文献   

11.

Background

Concerns about non-typeable Haemophilus influenzae (NTHi) in otitis media (OM) have grown after the introduction of pneumococcal conjugate vaccine (PCV). We aim to better understand the clinical role of NTHi in pediatric OM.

Methods

Middle ear fluid samples from children <18 years with OM were obtained from 2010 to 2015. For culture-positive episodes (Streptococcus pneumoniae, H. influenzae, Moraxella catarrhalis, and Streptococcus pyogenes), patients' demographic and clinical information were reviewed and analyzed.

Results

A total of 783 episodes were included with 31.8% of isolates as positive. S. pneumoniae was recovered in 69.4%, NTHi in 24.6%, M. catarrhalis in 5.6%, and S. pyogenes in 4.0% of culture-positive episodes. The proportion of pneumococcal OM has declined since 2012 (P for trend <0.005), but NTHi OM rose simultaneously (P for trend = 0.009). Factors associated with increased risk of NTHi infection included less spontaneous otorrhea (OR 0.15, 95% CI 0.06–0.39, P < 0.001), absence of fever (OR 0.30, 95% CI 0.14–0.66, P = 0.003), concurrent sinusitis (OR 2.91, 95% CI 1.36–6.20, P = 0.006), previous ventilation tube insertion (OR 12.02, 95% CI 3.15–45.92, P < 0.001) and recurrent OM (OR 3.43, 95% CI 1.01–11.71, P = 0.049). The susceptibility of NTHi to amoxicillin/clavulanate was 82.0%.

Conclusions

NTHi OM has trended upward in the post-PCV era. Concurrent sinusitis, previous ventilation tube insertion, and recurrent OM were associated with NTHi OM implicated a correlation between NTHi and complex OM. In consideration of NTHi infection, we suggest amoxicillin/clavulanate as the first-line therapy for OM among Taiwanese children.  相似文献   

12.

Objective

In the EPaNIC RCT (N=4640), postponing the administration of parenteral nutrition (PN) to beyond 1 week in the intensive care unit (ICU) (late-PN) reduced the number of ICU-acquired infections and the costs for antimicrobial drugs compared with initiation of PN within 24–48 hours of admission (early-PN). In a secondary analysis, we hypothesize that late-PN reduces the odds to acquire an invasive fungal infection (IFI) in the ICU.

Methods

The impact of late-PN (N=2328) versus early-PN (N=2312) on acquired IFI and on the likelihood to acquire an IFI over time was assessed in univariable and multivariable analyses. Subsequently, we performed multivariable analyses to assess the effect of the mean total daily administered calories from admission until day 3, day 5, and day 7 on the likelihood over time of acquiring an IFI.

Results

Fewer late-PN patients acquired an IFI compared with early-PN patients (77/2328 versus 112/2312) (p 0.008). After adjusting for risk factors, the odds to acquire an IFI and the likelihood of acquiring an IFI at any time were lower in late-PN (adjusted odds ratio 0.66, 95% CI 0.48–0.90, p 0.009; adjusted hazard ratio (HRadj) 0.70, 95% CI 0.52–0.93, p 0.02). Larger caloric amounts from admission until day 7 were associated with a higher likelihood to acquire an IFI over time (HRadj 1.09, 95% CI 1.02–1.16, p 0.009).

Conclusion

Postponing PN to beyond 1 week and smaller caloric amounts until day 7 in the ICU reduced ICU-acquired IFIs and the likelihood to develop an IFI over time.  相似文献   

13.

Objectives

We have noticed that patients colonized with methicillin-susceptible Staphylococcus aureus (MSSA) rarely get methicillin-resistant S. aureus (MRSA) infections. The purpose of this study was to compare the odds of a Staphylococcus aureus (SA) infection being an MRSA infection in MSSA carriers, MRSA carriers and non-carriers of SA.

Methods

Hospitalizations of adult patients at the Cleveland Clinic Health System from 2008 to 2015 were screened to identify those where the patient was tested for SA colonization. The first such hospitalization was identified. Among these 90 891 patients, those who had an SA infection during the hospitalization were included. SA carrier status (MRSA, MSSA, or non-carrier), was defined based on the first nasal SA test result. The association of carrier status and MRSA infection was examined.

Results

The mean (±standard deviation (SD)) age of the 1999 included patients was 61 (17) years, and 1160 (58%) were male. Thirty percent, 26%, and 44%, were MRSA carriers, MSSA carriers and non-carriers, respectively. Of the 601 SA infections in MRSA carriers (reference group), 552 (92%) were MRSA infections compared with 42 (8%) of 516 in MSSA carriers (odds ratio (OR) 0.008, 95% confidence interval (CI) 0.005–0.012, p <0.0001) and 430 (49%) of 882 in non-carriers (OR 0.072, 95% CI 0.051–0.100, p <0.0001), after controlling for age, sex, hospital length of stay and calendar year.

Conclusion

Among patients with SA infection, the odds of the infection being an MRSA infection are 125-times lower in an MSSA carrier than in an MRSA carrier.  相似文献   

14.

Objectives

Rapid detection of macrolide resistance–associated mutations in Mycoplasma pneumoniae is crucial for effective antimicrobial treatment. We evaluated the Lightmix Mycoplasma macrolide assay for the detection of point mutations at nucleotide positions 2063 and 2064 in the 23S ribosomal RNA (rRNA) gene of M. pneumoniae that confer macrolide resistance.

Methods

Samples from 3438 patients with a respiratory tract infection were analysed by M. pneumoniae real-time PCR, and 208 (6%) of them were tested positive. In this retrospective study, 163 M. pneumoniae real-time PCR–positive samples were analysed by the Lightmix assay, and results were compared to targeted 23S rRNA sequencing.

Results

Macrolide-resistant M. pneumoniae were found in 15 (9%) of 163 retrospectively analysed samples. The Lightmix assay showed a sensitivity of 100% (95% confidence interval, 78.2–100) and a specificity of 100% (95% confidence interval, 97.5–100) as the detected M. pneumoniae genotype (148 wild type and 15 non–wild type) was confirmed by 23S rRNA sequencing in all samples.

Conclusions

The Lightmix assay is an easy-to-use and accurate molecular test that allows rapid determination of macrolide resistance in M. pneumoniae.  相似文献   

15.

Background

The vaginal microbiota may modulate susceptibility to human papillomavirus (HPV), Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium infections. Persistent infection with a carcinogenic HPV is a prerequisite for cervical cancer, and C. trachomatis, N. gonorrheae and M. genitalium genital infections are all associated with pelvic inflammatory disease and subsequent infertility issues.

Objectives

To evaluate the association between these infections and the vaginal microbiota.

Data sources

The search was conducted on Medline and the Web of Science for articles published between 2000 and 2016.

Study eligibility criteria

Inclusion criteria included a measure of association for vaginal microbiota and one of the considered STIs, female population, cohort, cross-sectional and interventional designs, and the use of PCR methods for pathogen detection.

Methods

The vaginal microbiota was dichotomized into high-Lactobacillus vaginal microbiota (HL-VMB) and low-Lactobacillus vaginal microbiota (LL-VMB), using either Nugent score, Amsel's criteria, presence of clue cells or gene sequencing. A random effects model assuming heterogeneity among the studies was used for each STI considered.

Results

The search yielded 1054 articles, of which 39 met the inclusion criteria. Measures of association with LL-VMB ranged from 0.6 (95% CI 0.3–1.2) to 2.8 (95% CI 0.3–28.0), 0.7 (95% CI 0.4–1.2) to 5.2 (95% CI 1.9–14.8), 0.8 (95% CI 0.5–1.4) to 3.8 (95% CI 0.4–36.2) and 0.4 (95% CI 0.1–1.5) to 6.1 (95% CI 2.0–18.5) for HPV, C. trachomatis, N. gonorrhoeae and M. genitalium infections, respectively.

Conclusions

Although no clear trend for N. gonorrhoeae and M. genitalium infections could be detected, our results support a protective role of HL-VMB for HPV and C. trachomatis. Overall, these findings advocate for the use of high-resolution characterization methods for the vaginal microbiota and the need for longitudinal studies to lay the foundation for its integration in prevention and treatment strategies.  相似文献   

16.

Objectives

To investigate the incidence, risk factors, clinical course and outcomes of pregnancy-related group A streptococcus (GAS) infection.

Methods

A retrospective 13-year cohort study of culture-proven pregnancy-related GAS infection was performed at two university hospitals serving heterogeneous, multicultural, urban and rural populations.

Results

Of 124 women diagnosed with pregnancy-related GAS infection, 115 (93%) were in the puerperium, an incidence of 0.8 cases per 1000 live births (95% confidence interval, 0.7–0.9). A multivariate analysis showed primiparity and cesarean delivery to be independent protective factors against puerperal GAS infection (adjusted odds ratios (95% confidence interval), 0.60 (0.38, 0.97) and 0.44 (0.23, 0.81), respectively). Of the nine remaining patients, eight were diagnosed after first trimester abortions and one had an infected ectopic pregnancy. Among the entire cohort (n = 124), the predominant manifestations were fever and abdominal tenderness. Twenty-eight patients (23%) had severe GAS infections. All were treated with β-lactams, and most (n = 104, 84%) received clindamycin. Only four (3%) required surgical intervention; the rest fully recovered with conservative medical treatment including antibiotics. No recurrences, maternal deaths or neonatal complications were noted.

Conclusions

Pregnancy-related GAS infection is not rare; it lacks specific signs and still carries significant morbidity. Primiparity, a presumable surrogate for diminished exposure to children and thus less GAS carriage, and cesarean delivery in which perioperative antibiotic prophylaxis was uniformly provided, appear as protective factors against puerperal GAS infection. This hints to the importance of community-acquired GAS and may support shifting efforts from infection-control–oriented nosocomial investigations to screening and prevention–driven policies.  相似文献   

17.

Objectives

The mcr-1 gene is the first reported plasmid-mediated colistin resistance gene. It has caused worldwide concern about the colistin resistance in Gram-negative bacteria. The aim of this research was to study the impact of mcr-1 on the selection of high-level colistin resistance (HLCR) mutations in Escherichia coli and Klebsiella pneumoniae.

Methods

We detected the HLCR mutation rates of Enterobacteriaceae strains (K. pneumoniae XH209, KP10, and E. coli Q3, ATCC 25922) and their transformants harbouring the mcr-1 gene. Further analysis of the HLCR mutants was conducted by sequencing, plasmid elimination experiment, and real-time quantitative PCR.

Results

For XH209, mean mutation rate of XH209-pMCR was 1.7 (95% confidence interval (CI) 0.76–2.54) × 10?8, while XH209 and XH209-pCR2.1 showed mutation rates of 2.0 (95% CI, 1.32–2.67) × 10?8 and 2.3 (95% CI 1.47–3.13) × 10?8. For KP10 and its derived strains KP10-pCR2.1, KP10-pMCR, the mutation rates were 3.5 (95% CI 0.77–6.13) × 10?8, 4.8 (95% CI 0.69–8.94) × 10?8 and 4.2 (95% CI 0.95–7.54) × 10?8 respectively. The mutation rates of E. coli strains Q3-pMCR and ATCC25922-pMCR were 3.4 (95% CI 0.19–7.47) × 10?8 and 1.54 (95% CI 0.27–2.8) × 10?9, which were significantly higher than their corresponding non-mcr-1-carrying strains (p < 0.05).

Conclusions

Beside the knowledge that mcr-1 mediates low-level colistin resistance, this gene also facilitates selection of HLCR mutants in E. coli, but does not affect K. pneumoniae.  相似文献   

18.

Objectives

To investigate the contribution to virulence of the surface protein internalin B (InlB) in the Listeria monocytogenes lineage I strain F2365, which caused a deadly listeriosis outbreak in California in 1985.

Methods

The F2365 strain displays a point mutation that hampers expression of InlB. We rescued the expression of InlB in the L. monocytogenes lineage I strain F2365 by introducing a point mutation in the codon 34 (TAA to CAA). We investigated its importance for bacterial virulence using in vitro cell infection systems and a murine intravenous infection model.

Results

In HeLa and JEG-3 cells, the F2365 InlB+ strain expressing InlB was ≈9-fold and ≈1.5-fold more invasive than F2365, respectively. In livers and spleens of infected mice at 72 hours after infection, bacterial counts for F2365 InlB+ were significantly higher compared to the F2365 strain (≈1 log more), and histopathologic assessment showed that the F2365 strain displayed a reduced number of necrotic foci compared to the F2365 InlB+ strain (Mann-Whitney test).

Conclusions

InlB plays a critical role during infection of nonpregnant animals by a L. monocytogenes strain from lineage I. A spontaneous mutation in InlB could have prevented more severe human morbidity and mortality during the 1985 California listeriosis outbreak.  相似文献   

19.

Background

Genitourinary tuberculosis (GUTB) is rare but fatal if not diagnosed early. The purpose of this study was to investigate the outcomes of GUTB in Taiwan.

Methods

We retrospectively reviewed medical records of 57 patients who were diagnosed as GUTB from January 2002 to December 2016, over a 15-year period. Demographic data and clinical manifestations were recorded for analysis.

Results

There were 37 males and 20 females with a median age of 71 years. Kidney (24.6%) was the most involved organ. Fever (56.1%) was the major presentation. Sixteen (28.1%) patients presented unfavorable outcome. Compared with the favorable outcome group, the unfavorable outcome group had more malignancy (p = 0.013), fever (p = 0.020), anemia (p = 0007), thrombocytopenia (p = 0.003), and hypoalbuminemia (p = 0.015). In a multivariate analysis, fever (odds ratio: 42.716, 95% confidence interval: 1.032–1767.569; p = 0.048) was identified as prognostic factors for unfavorable outcome.

Conclusion

GUTB is often in advanced stages with a high mortality in Taiwan. Establishing a diagnosis is difficult and requires thorough investigation. Fever is associated with unfavorable outcome.  相似文献   

20.

Objectives

Therapy with antibiotics, dexamethasone, and supportive intensive care has improved the prognosis of pneumococcal meningitis, but mortality remains high. Here, we investigated an adjunctive combination therapy of the non-bacteriolytic antibiotic daptomycin plus several anti-inflammatory agents to identify the currently most promising adjunctive combination therapy for pneumococcal meningitis.

Methods

C57BL/6 mice were infected by injection of pneumococci into the cisterna magna. Treatment was begun 21 h after infection, and consisted of ceftriaxone plus (a) dexamethasone, (b) dexamethasone plus daptomycin, (c) daptomycin, (d) daptomycin plus an anti-IL1 antibody, (e) daptomycin plus roscovitine, or (f) daptomycin plus an anti-C5 antibody. Animals were followed until 45 h after infection. Furthermore, adjunctive daptomycin plus anti-C5 antibodies were assessed in a long-term follow-up.

Results

Adjunctive treatment with daptomycin and an anti-C5 antibody was superior to adjunctive dexamethasone and reduced disease symptoms (clinical score 1.1 ± 1.1 versus 5.0 ± 2.7, p < 0.0083), improved explorative activity (open field test 17.8 ± 8.2 versus 7.4 ± 4.3 crossed fields/2 minutes, p < 0.0083), and reduced hearing impairment (thresholds for click stimulus 96.1 ± 14.7 versus 114.8 ± 9.3 dB SPL, p < 0.0083) in the acute stage. Furthermore, explorative activity (14.4 ± 7.3 crossed fields/2 minutes versus 6.3 ± 7.2, p < 0.05) and cognitive function (t-maze test, exploration time previously unknown alley 72.4 ± 14.3 versus 48.7 ± 25.6%, p < 0.05) was improved at 2 weeks after infection. Treatment with daptomycin plus an anti-IL-1β antibody or roscovitine was not of significant benefit in comparison to adjunctive therapy with dexamethasone.

Conclusions

An adjunctive combination of the non-lytic antibiotic daptomycin plus an anti-C5 antibody was superior to standard therapy with adjunctive dexamethasone in the treatment of pneumococcal meningitis.  相似文献   

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