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Jang W, Jo HU, Kim B, Kwon KT, Ryu SY, Wie SH, Kim J, Park SY, Hong KW, Kim HI, Kim HA, Kim MH, Bae MH, Sohn YH, Kim J, Lee Y, Pai H. Comparison of the clinical characteristics of community-acquired acute pyelonephritis between male and female patients. J Infect Chemother 2021; 27:1013-1019. [PMID: 33642250 DOI: 10.1016/j.jiac.2021.02.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/07/2021] [Accepted: 02/14/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Community-acquired acute pyelonephritis (CA-APN) is relatively rare in men. This study aimed to compare the clinical characteristics of CA-APN between male and female patients. METHODS We prospectively collected the clinical and microbiological data of hospitalized CA-APN patients aged ≥19 years in South Korea from March 2010 to February 2011 in 11 hospitals and from September 2017 to August 2018 in 8 hospitals. Only the first episodes of APN of each patient during the study period were included. RESULTS From 2010 to 2011, 573 patients from 11 hospitals were recruited, and from 2017 to 2018, 340 patients were recruited from 8 hospitals. Among them, 5.9% (54/913) were male. Male patients were older (66.0 ± 15.2 vs. 55.3 ± 19.0 years, P < 0.001), had a higher Charlson comorbidity index (1.3 ± 1.5 vs. 0.7 ± 1.2, P = 0.027), and had a higher proportion of structural problems in the urinary tract (40.7% vs. 6.1%, P < 0.001) than female patients. Moreover, the total duration of antibiotic treatment was longer (21.8 ± 17.8 d vs. 17.3 ± 9.4 d, P = 0.001) and the proportion of carbapenem usage was higher (24.1% vs. 9.5%, P = 0.001) in men than in women. Male patients were hospitalized for longer durations than female patients (median, 10 d vs. 7 d, P < 0.001). CONCLUSIONS Male CA-APN patients were older and had more comorbidities than female CA-APN patients. In addition, male patients received antibiotic treatment for a longer duration than female patients.
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Affiliation(s)
- Wooyoung Jang
- School of Medicine, Hanyang University College of Medicine, Seoul, South Korea
| | - Hyun-Uk Jo
- Department of Urology, Good Moonhwa Hospital, Busan, South Korea
| | - Bongyoung Kim
- Department of Internal Medicine, College of Medicine, Hanyang University, Seoul, South Korea.
| | - Ki Tae Kwon
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Seong-Yeol Ryu
- Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, South Korea
| | - Seong-Heon Wie
- Division of Infectious Diseases, Department of Internal Medicine, St. Vincent Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Jieun Kim
- Department of Internal Medicine, College of Medicine, Hanyang University, Seoul, South Korea
| | - Se Yoon Park
- Division of Infectious Diseases, Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul, South Korea
| | - Kyung-Wook Hong
- Division of Infectious Diseases, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University School of Medicine, Jinju, South Korea
| | - Hye In Kim
- Department of Internal Medicine, Daegu Fatima Hospital, Daegu, South Korea
| | - Hyun Ah Kim
- Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, South Korea
| | - Mi-Hee Kim
- Division of Infectious Diseases, Department of Internal Medicine, St. Vincent Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Mi Hyun Bae
- Department of Laboratory Medicine, College of Medicine, Hanyang University, Seoul, South Korea
| | | | - Jieun Kim
- Department of Laboratory Medicine, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul, South Korea
| | - Yangsoon Lee
- Department of Laboratory Medicine, College of Medicine, Hanyang University, Seoul, South Korea
| | - Hyunjoo Pai
- Department of Internal Medicine, College of Medicine, Hanyang University, Seoul, South Korea.
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Leihof RF, Ethelberg S, Nielsen KL, Rasmussen SC, Frimodt-Møller N. Nosocomial urinary tract infection and risk of bacteraemia in elderly patients: urinary catheter, clinical factors and bacterial species. Infect Dis (Lond) 2019; 51:547-549. [DOI: 10.1080/23744235.2019.1599135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Rikke F. Leihof
- Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen S, Denmark
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
| | - Steen Ethelberg
- Department of Infectious Disease Epidemiology, Statens Serum Institut, Copenhagen S, Denmark
| | - Karen Leth Nielsen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen Ø, Denmark
| | - Steen C. Rasmussen
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
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Vázquez-Martínez ER, García-Gómez E, Camacho-Arroyo I, González-Pedrajo B. Sexual dimorphism in bacterial infections. Biol Sex Differ 2018; 9:27. [PMID: 29925409 PMCID: PMC6011518 DOI: 10.1186/s13293-018-0187-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/08/2018] [Indexed: 12/21/2022] Open
Abstract
Background Sex differences are important epidemiological factors that impact in the frequency and severity of infectious diseases. A clear sexual dimorphism in bacterial infections has been reported in both humans and animal models. Nevertheless, the molecular mechanisms involved in this gender bias are just starting to be elucidated. In the present article, we aim to review the available data in the literature that report bacterial infections presenting a clear sexual dimorphism, without considering behavioral and social factors. Main body The sexual dimorphism in bacterial infections has been mainly attributed to the differential levels of sex hormones between males and females, as well as to genetic factors. In general, males are more susceptible to gastrointestinal and respiratory bacterial diseases and sepsis, while females are more susceptible to genitourinary tract bacterial infections. However, these incidences depend on the population evaluated, animal model and the bacterial species. Female protection against bacterial infections and the associated complications is assumed to be due to the pro-inflammatory effect of estradiol, while male susceptibility to those infections is associated with the testosterone-mediated immune suppression, probably via their specific receptors. Recent studies indicate that the protective effect of estradiol depends on the estrogen receptor subtype and the specific tissue compartment involved in the bacterial insult, suggesting that tissue-specific expression of particular sex steroid receptors contributes to the susceptibility to bacterial infections. Furthermore, this gender bias also depends on the effects of sex hormones on specific bacterial species. Finally, since a large number of genes related to immune functions are located on the X chromosome, X-linked mosaicism confers a highly polymorphic gene expression program that allows women to respond with a more expanded immune repertoire as compared with men. Conclusion Notwithstanding there is increasing evidence that confirms the sexual dimorphism in certain bacterial infections and the molecular mechanisms associated, further studies are required to clarify conflicting data and to determine the role of specific hormone receptors involved in the gender bias of bacterial infections, as well as their potential as therapeutic targets.
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Affiliation(s)
- Edgar Ricardo Vázquez-Martínez
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Elizabeth García-Gómez
- Unidad de Investigación en Reproducción Humana, Consejo Nacional de Ciencia y Tecnología (CONACyT)-Instituto Nacional de Perinatología, Ciudad de México, Mexico
| | - Ignacio Camacho-Arroyo
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, UNAM, Ciudad Universitaria, Av. Universidad 3000, Coyoacán, 04510, Ciudad de México, Mexico.
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Seasonal Variation of Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae Bacteremia According to Acquisition and Patient Characteristics: A Population-Based Study. Infect Control Hosp Epidemiol 2016; 37:946-953. [PMID: 27142942 DOI: 10.1017/ice.2016.89] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Seasonal variation is a characteristic of many infectious diseases, but relatively little is known about determinants thereof. We studied the impact of place of acquisition and patient characteristics on seasonal variation of bacteremia caused by the 3 most common pathogens. DESIGN Seasonal variation analysis. METHODS In 3 Danish health regions (2.3 million total inhabitants), patients with bacteremia were identified from 2000 through 2011 using information from laboratory information systems. Analyses were confined to Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. Additional data were obtained from the Danish National Hospital Registry for the construction of admission histories and calculation of the Charlson comorbidity index (CCI). Bacteremias were categorized as community acquired, healthcare associated (HCA), and hospital acquired. We defined multiple subgroups by combining the following characteristics: species, acquisition, age group, gender, CCI level, and location of infection. Assuming a sinusoidal model, seasonal variation was assessed by the peak-to-trough (PTT) ratio with a 95% confidence interval (CI). RESULTS In total, we included 16,006 E. coli, 6,924 S. aureus, and 4,884 S. pneumoniae bacteremia cases. For E. coli, the seasonal variation was highest for community-acquired cases (PTT ratio, 1.24; 95% CI, 1.17-1.32), was diminished for HCA (PTT ratio, 1.14; 95% CI, 1.04-1.25), and was missing for hospital-acquired cases. No seasonal variation was observed for S. aureus. S. pneumoniae showed high seasonal variation, which did not differ according to acquisition (overall PTT ratio, 3.42; 95% CI, 3.10-3.83). CONCLUSIONS Seasonal variation was mainly related to the species although the place of acquisition was important for E. coli. Infect Control Hosp Epidemiol 2016;37:946-953.
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Abstract
Pathogenic Escherichia coli strains cause a wide variety of intestinal and extraintestinal infections. The widespread geographical clonal dissemination of intestinal pathogenic E. coli strains, such as E. coli O157:H7, is well recognized, and its spread is most often attributed to contaminated food products. On the other hand, the clonal dissemination of extraintestinal pathogenic E. coli (ExPEC) strains is also recognized, but the mechanism of their spread is not well explained. Here, I describe major pandemic clonal lineages of ExPEC based on multilocus sequence typing (MLST), and discuss possible reasons for their global dissemination. These lineages include sequence type (ST)131, ST393, ST69, ST95, and ST73, which are all associated with both community-onset and healthcare-associated infections, in particular urinary tract infections and bloodstream infections. As with many other types of drug-resistant Gram-negative and Gram-positive bacterial infections, drug-resistant ExPEC infections are recognized to be caused by a limited set of clonal lineages. However, reported observations on these major pandemic lineages suggest that the resistance phenotype is not necessarily the determinant of their clonal dissemination. Both epidemiological factors and their intrinsic biological 'fitness' are likely to contribute. An important public health and clinical concern is that pandemicity itself may be a determinant of progressive drug resistance acquisition by clonal lineages. New research is urgently needed to better understand the epidemiological and biological causes of ExPEC pandemicity.
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Affiliation(s)
- L W Riley
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, CA, USA
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Blot S, Vandewoude K, Hoste E, De Waele J, Kint K, Rosiers F, Vogelaers D, Colardyn F. Absence of Excess Mortality in Critically Ill Patients With Nosocomial Escherichia coli Bacteremia. Infect Control Hosp Epidemiol 2015; 24:912-5. [PMID: 14700406 DOI: 10.1086/502159] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractObjective:To evaluate excess mortality in critically ill patients with Escherichia coli bacteremia after adjustment for severity of illness.Design:Retrospective (1992-2000), pairwise-matched (1:2), risk-adjusted cohort study.Setting:Fifty-four-bed ICU in a university hospital including a medical and surgical ICU, a unit for care after cardiac surgery, and a burns unit.Patients:ICU patients with nosocomial E. coli bacteremia (defined as cases; n = 64) and control-patients without nosocomial bloodstream infection (n = 128).Methods:Case-patients were matched with control-patients on the basis of the Acute Physiology and Chronic Health Evaluation (APACHE) II system: an equal APACHE II score (± 2 points) and diagnostic category. In addition, control-patients were required to have an ICU stay at least as long as that of the respective case-patients prior to onset of the bacteremia.Results:The overall rate of appropriate antibiotic therapy in patients with E. coli bacteremia was high (93%) and such therapy was initiated soon after onset of the bacteremia (0.6 ± 1.0 day). ICU patients with E. coli bacteremia had more acute renal failure. No differences were noted between case-patients and control-patients in incidence of acute respiratory failure, hemodynamic instability, or age. No differences were observed in length of mechanical ventilation or length of ICU stay. In-hospital mortality rates for cases and controls were not different (43.8% and 45.3%, respectively; P = .959).Conclusion:After adjustment for disease severity and acute illness and in the presence of adequate antibiotic therapy, no excess mortality was found in ICU patients with E. coli bacteremia.
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Affiliation(s)
- Stijn Blot
- Department of Intensive Care, Ghent University Hospital, Ghent, Belgium
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Wie SH, Ki M, Kim J, Cho YK, Lim SK, Lee JS, Kwon KT, Lee H, Cheong HJ, Park DW, Ryu SY, Chung MH, Pai H. Clinical characteristics predicting early clinical failure after 72 h of antibiotic treatment in women with community-onset acute pyelonephritis: a prospective multicentre study. Clin Microbiol Infect 2014; 20:O721-9. [PMID: 24330047 DOI: 10.1111/1469-0691.12500] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/26/2013] [Accepted: 12/06/2013] [Indexed: 01/11/2023]
Abstract
In patients with community-onset acute pyelonephritis (CO-APN), assessing the risk factors for poor clinical response after 72 h of antibiotic treatment (early clinical failure) is important. The objectives of this study were to define those risk factors, and to assess whether early clinical failure influences mortality and treatment outcomes. We prospectively collected the clinical and microbiological data of women with CO-APN in South Korea from March 2010 to February 2012. The numbers of cases in the early clinical success and early clinical failure groups were 840 (79.1%) and 222 (20.9%), respectively. Final clinical failure and mortality were higher in the early clinical failure group than in the early clinical success group (14.9% vs 2.3%, p <0.001; 6.8% vs 0.1%, p 0.001, respectively). In a multiple logistic regression model, the risk factors for early clinical failure among the total 1062 patients were diabetes mellitus (OR 1.5; 95% CI 1.1-2.1), chronic liver diseases (OR 3.3; 95% CI 1.6-6.7), malignancy (OR 2.2; 95% CI 1.1-4.4), Pitt score ≥2 (OR 2.5; 95% CI 1.6-3.8), presence of azotaemia (OR 1.8; 95% CI 1.2-2.7), white blood cell count ≥20 000/mm(3) (OR 2.5; 95% CI 1.6-4.0), serum C-reactive protein level ≥20 mg/dL (OR 1.7; 95% CI 1.2-2.4), and history of antibiotic usage within the previous year (OR 1.5; 95% CI 1.1-2.2). Analysing the subgroup of 743 patients with CO-APN due to Enterobacteriaceae, fluoroquinolone resistance of the uropathogen was another factor associated with early clinical failure (OR 1.7; 95% CI 1.1-2.5). Simple variables of underlying diseases, previous antibiotic usage and initial laboratory test outcomes can be used to decide on the direction of treatment in CO-APN.
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Affiliation(s)
- S-H Wie
- Department of Internal Medicine, St Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Williamson DA, Lim A, Wiles S, Roberts SA, Freeman JT. Population-based incidence and comparative demographics of community-associated and healthcare-associated Escherichia coli bloodstream infection in Auckland, New Zealand, 2005-2011. BMC Infect Dis 2013; 13:385. [PMID: 23964864 PMCID: PMC3849480 DOI: 10.1186/1471-2334-13-385] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/08/2013] [Indexed: 11/16/2022] Open
Abstract
Background Escherichia coli is a major human pathogen, both in community and healthcare settings. To date however, relatively few studies have defined the population burden of E. coli bloodstream infections. Such information is important in informing strategies around treatment and prevention of these serious infections. Against this background, we performed a retrospective, population-based observational study of all cases of E. coli bacteremia in patients presenting to our hospital between January 2005 and December 2011. Methods Auckland District Health Board is a tertiary-level, university-affiliated institution serving a population of approximately 500,000, within a larger metropolitan population of 1.4 million. We identified all patients with an episode of bloodstream infection due to E. coli over the study period. A unique episode was defined as the first positive E. coli blood culture taken from the same patient within a thirty-day period. Standard definitions were used to classify episodes into community- or healthcare-associated E. coli bacteremia. Demographic information was obtained for all patients, including: age; gender; ethnicity; length of stay (days); requirement for intensive care admission and all-cause, in-patient mortality. Results A total of 1507 patients had a unique episode of E. coli bacteremia over the study period. The overall average annual incidence of E. coli bacteremia was 52 per 100,000 population, and was highest in the under one year and over 65-year age groups. When stratified by ethnicity, rates were highest in Pacific Peoples and Māori (83 and 62 per 100,000 population respectively). The incidence of community-onset E. coli bacteremia increased significantly over the study period. The overall in-hospital mortality rate was 9% (135/1507), and was significantly higher in patients who had a hospital-onset E. coli bacteremia. Conclusions Our work provides valuable baseline data on the incidence of E. coli bacteremia in our locale. The incidence was higher that that described from other developed countries, with significant demographic variation, most notably in ethnic-specific incidence rates. Future work should assess the possible reasons for this disparity.
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Affiliation(s)
- Deborah A Williamson
- Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
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Skjøt-Rasmussen L, Ejrnæs K, Lundgren B, Hammerum AM, Frimodt-Møller N. Virulence factors and phylogenetic grouping of Escherichia coli isolates from patients with bacteraemia of urinary tract origin relate to sex and hospital- vs. community-acquired origin. Int J Med Microbiol 2012; 302:129-34. [DOI: 10.1016/j.ijmm.2012.03.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 03/06/2012] [Accepted: 03/10/2012] [Indexed: 10/28/2022] Open
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Marschall J, Zhang L, Foxman B, Warren DK, Henderson JP. Both host and pathogen factors predispose to Escherichia coli urinary-source bacteremia in hospitalized patients. Clin Infect Dis 2012; 54:1692-8. [PMID: 22431806 DOI: 10.1093/cid/cis252] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The urinary tract is the most common source for Escherichia coli bacteremia. Mortality from E. coli urinary-source bacteremia is higher than that from urinary tract infection. Predisposing factors for urinary-source E. coli bacteremia are poorly characterized. METHODS In order to identify urinary-source bacteremia risk factors, we conducted a 12-month prospective cohort study of adult inpatients with E. coli bacteriuria that were tested for bacteremia within ±1 day of the bacteriuria. Patients with bacteremia were compared with those without bacteremia. Bacterial isolates from urine were screened for 16 putative virulence genes using high-throughput dot-blot hybridization. RESULTS Twenty-four of 156 subjects (15%) had E. coli bacteremia. Bacteremic patients were more likely to have benign prostatic hyperplasia (56% vs 19%; P = .04), a history of urogenital surgery (63% vs 28%; P = .001), and presentation with hesitancy/retention (21% vs 4%; P = .002), fever (63% vs 38%; P = .02), and pyelonephritis (67% vs 41%; P = .02). The genes kpsMT (group II capsule) (17 [71%] vs 62 [47%]; P = .03) and prf (P-fimbriae family) (13 [54%] vs 40 [30%]; P = .02) were more frequent in the urinary strains from bacteremic patients. Symptoms of hesitancy/retention (odds ratio [OR], 7.8; 95% confidence interval [CI], 1.6-37), history of a urogenital procedure (OR, 5.4; 95% CI, 2-14.7), and presence of kpsMT (OR, 2.9; 95% CI, 1-8.2) independently predicted bacteremia. CONCLUSIONS Bacteremia secondary to E. coli bacteriuria was frequent (15%) in those tested for it. Urinary stasis, surgical disruption of urogenital tissues, and a bacterial capsule characteristic contribute to systemic invasion by uropathogenic E. coli.
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Affiliation(s)
- Jonas Marschall
- Division of Infectious Diseases, Washington University School of Medicine, St Louis, Missouri, USA
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Berger J, Diab-Elschahawi M, Blacky A, Pernicka E, Spertini V, Assadian O, Koller W, Aichberger KJ. A matched prospective cohort study on Staphylococcus aureus and Escherichia coli bloodstream infections: extended perspectives beyond resistance. Am J Infect Control 2010; 38:839-45. [PMID: 20650546 DOI: 10.1016/j.ajic.2010.04.212] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/29/2010] [Accepted: 04/02/2010] [Indexed: 11/29/2022]
Abstract
BACKGROUND Bacteremias caused by Staphylococcus aureus and Escherichia coli are among the most common bloodstream infections (BSIs) in adults. The aim of the study was to investigate risk factors for infection and clinical outcomes of bacteremias caused by S aureus or E coli. METHODS We conducted a 1-year matched prospective cohort study including 150 patients with BSI caused by susceptible or resistant S aureus or E coli and 300 controls without BSI caused by these organisms. RESULTS Of the 150 episodes of bacteremia, 37% were caused by S aureus (including 5 cases of methicillin-resistant S aureus [MRSA]) and 63% were caused by E coli (including 9 cases of extended-spectrum beta lactamase [ESBL]-producing E coli). We identified 4 independent risk factors for acquisition of S aureus bacteremia (emergency, peripheral or central vascular catheter, renal disease) and 6 risk factors for E coli bacteremia (emergency, peripheral or central vascular catheter, malignancy, cytoreductive or immunosuppressive therapy). Both types of bacteremia were associated with an increased length of hospital stay compared with controls. We observed a 5-fold increase in the 30-day mortality rate for bacteremias due to S aureus, and a 2-fold increase in BSI caused by E coli. The in-hospital mortality rate was increased by 6-fold for S aureus and by 3-fold for E coli. CONCLUSION Longer hospitalization periods and increased mortality of bacteremias caused by S aureus or E coli, irrespective of susceptibility, implicate controlling for risk factors at an early stage.
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Thom KA, Shardell MD, Osih RB, Schweizer ML, Furuno JP, Perencevich EN, McGregor JC, Harris AD. Controlling for severity of illness in outcome studies involving infectious diseases: impact of measurement at different time points. Infect Control Hosp Epidemiol 2009; 29:1048-53. [PMID: 18817505 DOI: 10.1086/591453] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Severity of illness is an important confounder in outcome studies involving infectious diseases. However, it is unclear whether the time at which severity of illness is measured is important. METHODS We performed a retrospective study of 328 episodes of gram-negative bacteremia in adult patients to assess the impact of the time of measurement of severity of illness on the association between empirical antimicrobial therapy received and in-hospital mortality. Using a modified Acute Physiology Score (APS), severity of illness was measured at 2 time points: (1) hospital admission and (2) 24 hours before the first culture-positive blood sample was collected. Multivariate logistic regression was used to estimate the impact of adjusting for the APS on the relationship between empirical therapy received (ie, the exposure) and in-hospital mortality (ie, the outcome). RESULTS The mean APS (+/- standard deviation) of patients with bacteremia increased during their hospital stay (from 19.2 +/- 11.6 at admission to 24.2 +/- 13.6 at the second time point; P < .01). When examining the association between empirical antimicrobial therapy received and in-hospital mortality, and controlling for the APS, there was a trend toward a decreased impact of appropriate therapy received on in-hospital mortality. The unadjusted odds ratio (OR) for the association between appropriate therapy received and in-hospital mortality was 0.83 (95% confidence interval [CI], 0.51-1.34). After controlling for the APS at admission, this association was attenuated (OR, 0.94 [95% CI, 0.57-1.55]), and when a change in the APS was also included in the multivariate logistic regression model, the association was further attenuated (OR, 0.99 [95% CI, 0.58-1.69]). CONCLUSIONS The magnitude of the association between appropriate antimicrobial therapy received and in-hospital mortality among patients with gram-negative bacteremia was sensitive to the timing of adjustment for severity of illness.
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Affiliation(s)
- Kerri A Thom
- Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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Ortega M, Marco F, Soriano A, Almela M, Martínez JA, Muñoz A, Mensa J. Analysis of 4758 Escherichia coli bacteraemia episodes: predictive factors for isolation of an antibiotic-resistant strain and their impact on the outcome. J Antimicrob Chemother 2009; 63:568-74. [DOI: 10.1093/jac/dkn514] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Laupland KB, Gregson DB, Church DL, Ross T, Pitout JDD. Incidence, risk factors and outcomes of Escherichia coli bloodstream infections in a large Canadian region. Clin Microbiol Infect 2009; 14:1041-7. [PMID: 19040476 DOI: 10.1111/j.1469-0691.2008.02089.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Although Escherichia coli is the most common cause of bloodstream infection, its epidemiology has not been well defined in non-selected populations. We sought to describe the incidence of risk factors for, and outcomes associated with, E. coli bacteraemia. Population-based surveillance for E. coli bacteraemia was conducted in the Calgary Health Region (population 1.2 million) during the period 2000-2006. In total, 2368 episodes of E. coli bacteraemia were identified for an overall annual population incidence of 30.3/100 000; 15% were nosocomial, 32% were healthcare-associated community-onset and 53% were community-acquired bacteraemias. The very young and the elderly were at highest risk for E. coli bacteraemia. Sixty per cent of the episodes occurred in females (relative risk 1.5; 95% CI 1.4-1.6). Dialysis, solid organ transplantation and neoplastic disease were the most important risk factors for acquiring E. coli bacteraemia. Rates of resistance to ampicillin, trimethoprim-sulphamethoxazole, gentamicin, ciprofloxacin, cefazolin and ceftriaxone increased significantly during the period 2000-2006. The case-fatality rate was 11% and the annual population mortality rate was 2.9/100 000. Increasing age, ciprofloxacin resistance, non-urinary focus and a number of comorbid illnesses were independently associated with an increased risk of death, and community acquisition and urinary focus were associated with a lower risk of death. This study documents the major burden of illness associated with E. coli bacteraemia and identifies groups at increased risk for acquiring and dying from these infections. The emergence of ciprofloxacin resistance and its adverse effect on patient outcome is a major concern.
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Affiliation(s)
- K B Laupland
- Department of Medicine, University of Calgary, Calgary, ALberta, Canada.
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Thom KA, Schweizer ML, Osih RB, McGregor JC, Furuno JP, Perencevich EN, Harris AD. Impact of empiric antimicrobial therapy on outcomes in patients with Escherichia coli and Klebsiella pneumoniae bacteremia: a cohort study. BMC Infect Dis 2008; 8:116. [PMID: 18793400 PMCID: PMC2551598 DOI: 10.1186/1471-2334-8-116] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 09/15/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is unclear whether appropriate empiric antimicrobial therapy improves outcomes in patients with bacteremia due to Escherichia coli or Klebsiella. The objective of this study is to assess the impact of appropriate empiric antimicrobial therapy on in-hospital mortality and post-infection length of stay in patients with Escherichia coli or Klebsiella bacteremia while adjusting for important confounding variables. METHODS We performed a retrospective cohort study of adult patients with a positive blood culture for E. coli or Klebsiella between January 1, 2001 and June 8, 2005 and compared in-hospital mortality and post-infection length of stay between subjects who received appropriate and inappropriate empiric antimicrobial therapy. Empiric therapy was defined as the receipt of an antimicrobial agent between 8 hours before and 24 hours after the index blood culture was drawn and was considered appropriate if it included antimicrobials to which the specific isolate displayed in vitro susceptibility. Data were collected electronically and through chart review. Survival analysis was used to statistically assess the association between empiric antimicrobial therapy and outcome (mortality or length of stay). Multivariable Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS Among 416 episodes of bacteremia, 305 (73.3%) patients received appropriate empiric antimicrobial therapy. Seventy-one (17%) patients died before discharge from the hospital. The receipt of appropriate antimicrobial agents was more common in hospital survivors than in those who died (p = 0.04). After controlling for confounding variables, there was no association between the receipt of appropriate empiric antimicrobial therapy and in-hospital mortality (HR, 1.03; 95% CI, 0.60 to 1.78). The median post-infection length of stay was 7 days. The receipt of appropriate antimicrobial agents was not associated with shortened post-infection length of stay, even after controlling for confounding (HR, 1.11; 95% CI 0.86 to 1.44). CONCLUSION Appropriate empiric antimicrobial therapy for E. coli and Klebsiella bacteremia is not associated with lower in-hospital mortality or shortened post-infection length of stay. This suggests that the choice of empiric antimicrobial agents may not improve outcomes and also provides data to support a randomized trial to test the hypothesis that use (and overuse) of broad-spectrum antibiotics prior to the availability of culture results is not warranted.
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Affiliation(s)
- Kerri A Thom
- Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
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16
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Kennedy KJ, Roberts JL, Collignon PJ. Escherichia coli bacteraemia in Canberra: incidence and clinical features. Med J Aust 2008; 188:209-13. [PMID: 18279126 DOI: 10.5694/j.1326-5377.2008.tb01586.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 09/10/2007] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To determine the population incidence and clinical features of Escherichia coli bacteraemia in Canberra, Australia. DESIGN, SETTING AND PARTICIPANTS Canberra (including the nearby local government areas of Queanbeyan and Yarrowlumla) has a geographically isolated population of about 366 000 people. Its six hospitals also provide tertiary medical services for the surrounding region. Confining our analysis (by residential postcodes) to Canberra residents only, we used microbiology laboratory records and population statistics to calculate the population incidence of E. coli bacteraemia from January 2000 to December 2004. Clinical data were also collected prospectively on episodes occurring within three of the hospitals. MAIN OUTCOME MEASURES Population incidence of E. coli bacteraemia; place of acquisition of infection; focus of infection within body; recovery, new morbidity or death at 7 days. RESULTS During the 5-year period, 515 episodes of E. coli bacteraemia occurred in Canberra residents, an incidence of 28 per 100 000 population per year. The highest rate was in men aged > or = 80 years (463 per 100 000). Overall, E. coli bacteraemia occurred in equal numbers in males and females, but incidence was higher in males aged < 1 year and > or = 60 years. Most episodes occurred in people aged > or = 60 years (316/511 [62%]) and most were community-associated (347/511 [68%]). Half the infections (257/511) had a genitourinary focus and 28% (141/511) a gastrointestinal focus. The 7-day case-fatality rate was 5%. Prostate biopsies and urinary catheters were notable preventable foci of health care-associated bacteraemia. Resistance of isolates to gentamicin (2.1%), ciprofloxacin (1.8%) and cefotaxime (0.4%) was low. CONCLUSIONS E. coli is the most common cause of bacteraemia in Canberra, and incidence increases with age. Most cases have a community onset, but many episodes are related to health care procedures. Ongoing surveillance is important for identifying risk factors that may be modified to reduce disease.
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Affiliation(s)
- Karina J Kennedy
- Microbiology and Infectious Diseases, The Canberra Hospital, Canberra, ACT, Australia.
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17
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Peralta G, Roiz MP, Sánchez MB, Garrido JC, Ceballos B, Rodríguez-Lera MJ, Mateos F, De Benito I. Time-to-positivity in patients with Escherichia coli bacteraemia. Clin Microbiol Infect 2007; 13:1077-82. [PMID: 17727685 DOI: 10.1111/j.1469-0691.2007.01817.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The time from the start of incubation to a positive reading of blood cultures (time-to-positivity; TTP) is related to the concentration of bacteria in blood. Information concerning the correlation of TTP with clinical parameters, and its usefulness as a prognostic factor in patients with Escherichia coli bacteraemia, is limited. To investigate the relationship of TTP to clinical parameters, 459 cases of monomicrobial E. coli bloodstream infections from a single institution between 1997 and 2005 were reviewed. All cases involved patients who were not undergoing antibiotic treatment at the time of blood sampling. The in-hospital mortality rate was 6.3%. Median TTP was significantly shorter for patients who died than for those who survived (9.7 h, inter-quartile range 7.85-11.05 h vs. 11.2 h, inter-quartile range 10.1-11.4 h; p <0.001). Patients with TTP in the lowest quartile were more likely to be female, to have a non-urinary tract or an unknown origin of bacteraemia, to have severe sepsis or shock, and to subsequently die. In a multivariable Cox regression model, the hazard ratio for death from any cause for patients with a short TTP was 3.13 (95% CI 1.28-7.64; p 0.01). TTP in patients with E. coli bacteraemia provides prognostic information beyond that provided by the presence of haematological illness, a Charlson score > or =3, a non-urinary tract origin of bacteraemia, and the presence of severe sepsis or shock.
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Affiliation(s)
- G Peralta
- Internal Medicine Service, Sierrallana Hospital, Torrelavega, Cantabria, Spain.
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18
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Martínez JA, Soto S, Fabrega A, Almela M, Mensa J, Soriano A, Marco F, Jimenez de Anta MT, Vila J. Relationship of phylogenetic background, biofilm production, and time to detection of growth in blood culture vials with clinical variables and prognosis associated with Escherichia coli bacteremia. J Clin Microbiol 2006; 44:1468-74. [PMID: 16597878 PMCID: PMC1448679 DOI: 10.1128/jcm.44.4.1468-1474.2006] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In patients with Escherichia coli bacteremia, data on the relationship of phylogenetic background, biofilm production, and degree of bacteremia with clinical variables and prognosis are scarce. During a 1-year period, all adults with bacteremia due to Escherichia coli diagnosed at a university center were enrolled. Determination of phylogenetic background, biofilm production, and genotyping was performed with all strains, and the time to positivity of blood culture vials was recorded. A total of 185 episodes of diverse-source E. coli bacteremia was analyzed. Strains of phylogroup D were predominant (52%). Phylogroup A isolates were associated with pneumonia and prior antibiotic intake, B1 with an abdominal source of infection, B2 with the absence of urological abnormalities, and D with urological abnormalities and age below 65 years. Resistance to antibiotics and no biofilm production were concentrated in phylogroup A strains. Biofilm production was not associated with any clinical variable. An immunocompromising condition (odds ratio [OR] = 5.01, 95% confidence interval [CI] = 1.4 to 17.9), peritonitis (OR = 17, 95% CI = 3.32 to 87), pneumonia (OR = 9.97, 95% CI = 1.96 to 50.6), and </=7 h to bacteremia detection (OR = 4.37, 95% CI = 1.38 to 13.8) were the best predictors of a fatal outcome. Results from this study suggest that the distribution of phylogenetic backgrounds among E. coli strains involved in diverse-source bacteremia may be subject to geographical variation and that, in afflicted individuals, some high-risk sources, the patient's underlying condition, and the degree of bacteremia are more important than microbial factors in determining the outcome. Time to positivity of blood culture vials may be a variable of potential clinical impact.
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Affiliation(s)
- Jose A Martínez
- Department of Infectious Diseases, Hospital Clínic, Villarroel 170, 08036 Barcelona, Spain.
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19
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Reisner A, Krogfelt KA, Klein BM, Zechner EL, Molin S. In vitro biofilm formation of commensal and pathogenic Escherichia coli strains: impact of environmental and genetic factors. J Bacteriol 2006; 188:3572-81. [PMID: 16672611 PMCID: PMC1482849 DOI: 10.1128/jb.188.10.3572-3581.2006] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our understanding of Escherichia coli biofilm formation in vitro is based on studies of laboratory K-12 strains grown in standard media. However, pathogenic E. coli isolates differ substantially in their genetic repertoire from E. coli K-12 and are subject to heterogeneous environmental conditions. In this study, in vitro biofilm formation of 331 nondomesticated E. coli strains isolated from healthy (n = 105) and diarrhea-afflicted children (n = 68), bacteremia patients (n = 90), and male patients with urinary tract infections (n = 68) was monitored using a variety of growth conditions and compared to in vitro biofilm formation of prototypic pathogenic and laboratory strains. Our results revealed remarkable variation among the capacities of diverse E. coli isolates to form biofilms in vitro. Notably, we could not identify an association of increased biofilm formation in vitro with a specific strain collection that represented pathogenic E. coli strains. Instead, analysis of biofilm data revealed a significant dependence on growth medium composition (P < 0.05). Poor correlation between biofilm formation in the various media suggests that diverse E. coli isolates respond very differently to changing environmental conditions. The data demonstrate that prevalence and expression of three factors known to strongly promote biofilm formation in E. coli K-12 (F-like conjugative pili, aggregative adherence fimbriae, and curli) cannot adequately account for the increased biofilm formation of nondomesticated E. coli isolates in vitro. This study highlights the complexity of genetic and environmental effectors of the biofilm phenotype within the species E. coli.
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Affiliation(s)
- Andreas Reisner
- Molecular Microbial Ecology Group, Center for Biomedical Microbiology, BioCentrum-DTU, Technical University of Denmark, Lyngby.
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20
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Berild D, Mohseni A, Diep LM, Jensenius M, Ringertz SH. Adjustment of antibiotic treatment according to the results of blood cultures leads to decreased antibiotic use and costs. J Antimicrob Chemother 2005; 57:326-30. [PMID: 16387751 DOI: 10.1093/jac/dki463] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION To avoid the use of unnecessary broad-spectrum antibiotics, empirical therapy of bacteraemia should be adjusted according to the results of blood cultures. OBJECTIVES To investigate whether the results of blood cultures led to changes in antibiotic use and costs in a tertiary-care university hospital in Norway. METHODS Medical records from all patients with positive blood cultures in 2001 were analysed retrospectively. Factors predisposing to infections, results of blood cultures, antibiotic use and outcome were recorded. The influence of blood culture results on antibiotic treatment and costs were analysed. RESULTS The antibiotic use in 226 episodes of bacteraemia in 214 patients was analysed. According to the guidelines empirical antibiotic treatment should be adjusted in 166 episodes. Antibiotic use was adjusted in 146 (88%) of these 166 episodes, which led to a narrowing of therapy in 118 (80%) episodes. Compared with empirical therapy there was a 22% reduction in the number of antibiotics. Adjustment of therapy was more often performed in Gram-negative bacteraemia and polymicrobial cultures than in Gram-positive bacteraemia. In bacteraemia caused by ampicillin-resistant Escherichia coli, ampicillin was mostly replaced by ciprofloxacin. The cost for 7 days adjusted therapy in 146 episodes was euro19,800 (23%) less than for 7 days of empirical therapy. CONCLUSIONS Adjustment of antibiotic therapy according to the results of blood cultures led to a reduction in the number of antibiotics and a narrowing of antibiotic therapy. The costs for antibiotics decreased.
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Affiliation(s)
- Dag Berild
- Department of Internal Medicine, Aker University Hospital, N-0514 Oslo, Norway.
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21
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Javaloyas M, García-Somoza D, Gudiol F. [Bacteremia due to Escherichia coli: epidemiological analysis and sensitivity to antibiotics in a county hospital]. Med Clin (Barc) 2003; 120:125-7. [PMID: 12605835 DOI: 10.1016/s0025-7753(03)73623-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND OBJECTIVE There are few studies analyzing the epidemiological characteristics of Escherichia coli bacteremia including the susceptibility to antibiotics and outcome. PATIENTS AND METHOD E. coli bacteremia episodes were recorded from January 1989 to December 1998. Clinical variables, setting acquisition, source of bacteremia, outcome and susceptibility to antibiotics were included. The study was prospective and comparative. Descriptive and univariate analysis were performed. RESULTS 330 episodes of E. coli bacteremia were recorded: 117 in women. The most frequent source was the urinary tract (68%), followed by an abdominal and biliary focus. E. coli bacteremia appeared mostly in groups II and III of McCabe & Jackson. In 46 cases (14%), E. coli bacteremia was nosocomial. Crude and related mortality was 6.6 and 4.2%, respectively. A significant increase in the resistance to ciprofloxacin was observed. CONCLUSIONS The epidemiological characteristics of E. coli bacteremia have not changed, yet the mortality was lower in our series. Preventive measures in the hospital and a rational use of antibiotics, principally quinolones, are necessary.
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Affiliation(s)
- Manuel Javaloyas
- Servicios de Medicina Interna y Microbiología. Hospital de Viladecans. Viladecans. Barcelona
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Tseng CC, Wu JJ, Liu HL, Sung JM, Huang JJ. Roles of host and bacterial virulence factors in the development of upper urinary tract infection caused by Escherichia coli. Am J Kidney Dis 2002; 39:744-52. [PMID: 11920340 DOI: 10.1053/ajkd.2002.32992] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Aims of this study are to identify host and Escherichia coli virulence factors associated with upper urinary tract infection (UTI) by comparing them with those for lower UTI and determining the association between major predisposing host factors for upper UTI and urovirulence genes for E coli. Host factors and urovirulence genes of E coli associated with bacteremia in patients with upper UTI and their interactions also were studied. One hundred thirty-nine adult patients who fulfilled clinical diagnostic criteria for upper (n = 81) or lower UTI (n = 58) caused by E coli between January 1997 and December 1999 were retrospectively enrolled into this study. Old age (> or =60 years), male sex, diabetes with poor blood glucose control (ie, glycosylated hemoglobin A1C > or = 8.1%), immunosuppression, and urinary tract obstruction were more frequently associated host factors for patients with upper UTI than for those with lower UTI. Using polymerase chain reaction, the papG class II allele was detected more frequently for E coli strains isolated from patients with upper UTI than for those from patients with lower UTI (85% versus 52%; P < 0.0001). Multivariate analysis showed that diabetes with poor blood glucose control, immunosuppression, urinary tract obstruction, and papG class II allele were independently associated with upper UTI. For patients without these three predisposing host factors, the prevalence of papG class II allele was significantly greater in those with upper UTI than those with lower UTI. However, the papG class II allele was less prevalent in strains isolated from patients with upper UTI with urinary tract obstruction or with two of the three predisposing host factors. In addition, both univariate and multivariate analyses showed that old age and papG class II allele were risk factors for the development of E coli bacteremia in patients with upper UTI. In conclusion, both host and E coli virulence factors contribute to the development of upper UTI, and less virulent strains can cause upper UTI in hosts with predisposing factors.
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Affiliation(s)
- Chin-Chung Tseng
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan, Republic of China
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23
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Bruunsgaard H, Pedersen BK. Special feature for the Olympics: effects of exercise on the immune system: effects of exercise on the immune system in the elderly population. Immunol Cell Biol 2000; 78:523-31. [PMID: 11050535 DOI: 10.1111/j.1440-1711.2000.t01-14-.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Immunosenescence is characterized by impaired cellular immune function concomitant with increased inflammatory activity. Immune dysfunction is associated with increased mortality risk in elderly people. An important part of human ageing is characterized by a decline in the ability of individuals to adapt to environmental stress. Exercise has been suggested as a prototype for studying the effects of stress factors on the cellular immune system. Studies of interactions between an acute bout of exercise and immune function may be a useful and an ethically acceptable tool to investigate cell trafficking, immune mobilization/deficiency and the acute phase response during physical stress situations in relation to human ageing. Elderly humans have a preserved ability to recruit T lymphocytes and NK cells in response to an acute bout of exercise. Physical exercise training programs do not result in major restoration of the senescent immune system in humans. However, highly conditioned elderly humans seem to have a relatively better preserved immune system, although it is not possible to conclude if this is linked to training or other lifestyle-related factors.
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Affiliation(s)
- H Bruunsgaard
- Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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25
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Olesen B, Kolmos HJ, Orskov F, Orskov I. A comparative study of nosocomial and community-acquired strains of Escherichia coli causing bacteraemia in a Danish University Hospital. J Hosp Infect 1995; 31:295-304. [PMID: 8926379 DOI: 10.1016/0195-6701(95)90208-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In a previous study we found a considerably higher mortality rate in patients with nosocomial (NO) compared with community-acquired (CA) Escherichia coli bacteraemia. To establish whether this was due to host differences or to differences in the infecting bacteria, we compared 205 NO with 172 CA bacteraemic isolates of E. coli with respect to serotype, virulence factors and antimicrobial susceptibility. Overall the six most frequent O antigens were O18ac, O6, O1, O2, O15 and O75, respectively. The six most frequent capsular antigens were K1, K5, K52, K2, K7 and K34, respectively. No major differences were found regarding O-antigens, capsular antigens, production of haemolysin, P-fimbriation, serum sensitivity or antimicrobial susceptibility. Surprisingly we found 17 strains of serotype O15:K52:[H1] of both NO (eight) and CA (nine) origin with similar phenotypic characteristics to a strain causing a CA outbreak in London 1986-1987. Possibly the Danish and the English strains belong to the same clone. Our findings argue against the existence of a distinct NO flora. NO E. coli bacteraemia strains seem to originate primarily from the patients' own flora.
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Affiliation(s)
- B Olesen
- Department of Clinical Microbiology, University of Copenhagen, Denmark
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