H. von Baum

Fluoroquinolone resistance of Escherichia coli at a cancer center: epidemiologic evolution and effects of discontinuing prophylactic fluoroquinolone use in neutropenic patients with leukemia

The aim of the present study was to investigate the epidemiologic evolution of fluoroquinolone resistance of E. coli clinical isolates from patients admitted to a hematology-oncology service where fluoroquinolone prophylaxis during neutropenia was recommended as the standard of care for many years but was then discontinued in a trial conducted in patients with acute leukemia. Fluoroquinolones had been shown to decrease the incidence of gram-negative bacteremia in cancer patients with neutropenia, yet it was thought that the emergence of resistance in Escherichia coli and other gram-negative bacteria may have caused a progressive lack of efficacy of fluoroquinolone prophylaxis. Epidemiologic surveillance of fluoroquinolone resistance of E. coli clinical isolates at our cancer center since 1992 showed a continuing influx of new clones not previously observed in the population of cancer patients, an increase in the number of cancer patients per year colonized and/or infected by fluoroquinolone-resistant E. coli (1992–1994, 10–16 patients; 1995–1997, 24–27 patients), and a resistance rate of >50% among E. coli bloodstream isolates of hematology-oncology patients. A 6-month fluoroquinolone prophylaxis discontinuation intervention trial in 1998 suggested that despite increasing resistance among E. coli isolates, fluoroquinolone prophylaxis in acute leukemia patients was still effective in the prevention of gram-negative bacteremia (incidence rates, 8% during the pre-intervention period vs. 20% after discontinuation; p<0.01). The resumption of fluoroquinolone prophylaxis in acute leukemia patients thereafter decreased the incidence of gram-negative bacteremia to the pre-intervention level (9%; p=0.03), while the proportion of in vitro fluoroquinolone resistance in E. coli bacteremia isolates again increased (from 15% during the intervention period to >50% in the post-intervention period). Relative rates of resistance thus were a poor indicator of the potential clinical benefits associated with fluoroquinolone prophylaxis in cancer patients.

RISK FACTORS FOR METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS CARRIAGE IN RESIDENTS OF GERMAN NURSING HOMES

OBJECTIVES To determine the prevalence of and the risk factors for methicillin-resistant Staphylococcus aureus (MRSA) carriage in nursing home residents in the Rhine-Neckar region of southern Germany. DESIGN Point-prevalence survey. SETTING Forty-seven nursing homes in the region. PARTICIPANTS All residents of the approached nursing homes who agreed to participate. METHODS After informed consent was obtained, all participants had their nares swabbed, some personal data collected, or both. All swabs were examined for growth of MRSA. All S. aureus isolates underwent oxacillin susceptibility testing and polymerase chain reaction for demonstration of the mecA gene. All MRSA isolates were typed using pulsed-field gel electrophoresis after digestion with SmaI. RESULTS Swabs from 3,236 nursing home residents yielded 36 MRSA strains, contributing to a prevalence rate of 1.1%. Significant risk factors for MRSA carriage in the multivariate analysis were the presence of wounds or urinary catheters, limited mobility, admission to a hospital during the preceding 3 months, or stay in a medium-size nursing home. One predominant MRSA strain could be detected in 30 of the 36 MRSA carriers. CONCLUSIONS The prevalence of MRSA in German nursing homes is still low. These residents seemed to acquire their MRSA in the hospital and transfer it to their nursing home. Apart from well-known risk factors for the acquisition of MRSA, we identified the size of the nursing home as an independent risk factor. This might be due to an increased use of and microbials in nursing homes of a certain size.

Value of Whole‐Body Washing With Chlorhexidine for the Eradication of Methicillin‐Resistant Staphylococcus aureus: A Randomized, Placebo‐Controlled, Double‐Blind Clinical Trial

BACKGROUND Whole-body washing with antiseptic solution has been widely used as part of eradication treatment for colonization with methicillin-resistant Staphylococcus aureus (MRSA), but evidence for the effectiveness of this measure is limited. OBJECTIVE To study the efficacy of whole-body washing with chlorhexidine for the control of MRSA. DESIGN Randomized, placebo-controlled, double-blinded clinical trial. SETTING University Hospital of Heidelberg and surrounding nursing homes. PATIENTS MRSA carriers who were not treated concurrently with antibiotics effective against MRSA were eligible for the study. INTERVENTION Five days of whole-body washing with either 4% chlorhexidine solution (treatment group) or with a placebo solution. All patients received mupirocin nasal ointment and chlorhexidine mouth rinse. The outcome was evaluated 3, 4, 5, 9, and 30 days after treatment with swab samples taken from several body sites. RESULTS Of 114 patients enrolled in the study (56 in the treatment group and 58 in the placebo group), 11 did not finish treatment (8 from the treatment group and 3 from the placebo group [P=.02]). At baseline, the groups did not differ with regard to age, sex, underlying condition, site of MRSA colonization, or history of MRSA eradication treatment. Eleven patients were MRSA-free 30 days after treatment (4 from the treatment group and 7 from the placebo group [P=.47]). Only groin-area colonization was significantly better eradicated by the use of chlorhexidine. The best predictor for total eradication was a low number of body sites positive for MRSA. Adverse effects were significantly more frequent in the treatment group than in the placebo group (any symptom, 71% vs 33%) but were reversible in most cases. CONCLUSION Whole-body washing can reduce skin colonization, but it appears necessary to extend eradication measures to the gastrointestinal tract, wounds, and/or other colonized body sites if complete eradication is the goal.

Occurrence of macrolide-resistant Mycoplasma pneumoniae strains in Germany

In a total of 167 respiratory tract specimens from adult outpatients with confirmed Mycoplasma pneumoniae pneumonia, sampled between 2003 and 2008, and a further 99 isolates obtained from patients between 1991 and 2009 in Germany, M. pneumoniae was tested for macrolide resistance. Using PCR, real-time PCR and sequencing of the 23S rRNA gene, 1.2% of M. pneumoniae in the respiratory tract samples and 3.0% of the isolates were found to be resistant. The results indicate a limited but not negligible importance of macrolide-resistant M. pneumoniae in the population investigated, which requires the monitoring of macrolide susceptibility of isolates or the testing of respiratory samples by molecular methods.

Subtypes and variants of Mycoplasma pneumoniae : local and temporal changes in Germany 2003–2006 and absence of a correlation between the genotype in the respiratory tract and the occurrence of genotype-specific antibodies in the sera of infected patients

Mycoplasma pneumoniae is a frequent cause of community-acquired pneumonia. Three subtypes and three variants of M. pneumoniae have been described showing sequence differences in the main P1 adhesin. Between 2003 and 2006 we collected respiratory tract samples of adult outpatients with symptoms of pneumonia in a German nationwide network and detected M. pneumoniae by real-time PCR in 140 specimens. The strains were typed by sequencing and demonstrated the circulation of subtypes 1 and 2 and variants 2a and 2b. The overall number of isolates belonging to the two variant genotypes increased during the investigation period but the relationship of subtypes and variants within the participating local centres varied strongly. ELISA experiments using sera of acute-phase patients with a known M. pneumoniae type in the respiratory tract resulted in no correlation of IgA and IgG antibodies to subtype- and variant-specific regions of the P1 gene with the genotype of the M. pneumoniae strain causing the actual infection.

Risk factors for colonization with third-generation cephalosporin-resistant enterobacteriaceae.

Background and Method:Colonization and infections caused by Enterobacteriaceae resistant to third–generation cephalosporins (CRE) have been observed with increasing frequency in intensive care unit (ICU) patients. In contrast to outbreak investigations, information about risk factors for colonization in an endemic situation are rare. We studied risk factors for colonization with CRE in a case control study including 1,706 patients, admitted to any of the 15 ICUs of Heidelberg University Hospitals.Results:163 patients carried CRE with Enterobacter spp. representing the predominant species. Independent risk factors for CRE carriage in the multivariate logistic regression analysis were an age of under 2.5 years (OR 4.034), an indwelling central venous catheter (CVC) for more than 3 days (OR 2.640), treatment with second– or thirdgeneration cephalosporin for longer than 3 days (OR 2.260) and any antibiotic therapy before admission to the ICU.Conclusion:Apart from the well–recognized risk factor previous antibiotic treatment, the risk factors age and presence of a CVC might suggest that bacterial overgrowth of the gut either due to an increased susceptibility in younger age or as a consequence of parenteral nutrition is a relevant mechanism for acquiring carriage of CRE in a non–outbreak situation.

Characteristics that promote transmission of Staphylococcus aureus in German nursing homes

OBJECTIVE To determine factors that influence transmission of Staphylococcus aureus in nursing homes in the Rhine-Neckar region of southern Germany. DESIGN Ecologic study. SETTING Forty-seven nursing homes in the region. PARTICIPANTS Residents of the approached nursing homes who agreed to participate. METHODS Personal data and swabs of the nares were collected from participants. Swabs were examined for growth of S. aureus. All S. aureus isolates were typed using pulsed-field gel electrophoresis (PFGE). Transmission rates were calculated by dividing the number of transmissions (ie, cases in which two inhabitants shared the same PFGE type) by the number of S. aureus carriers. Characteristics of the nursing homes were correlated with a homes transmission rate. RESULTS In each nursing home, 12% to 54% of the residents were colonized with S. aureus. The transmission rates for the 47 nursing homes ranged from 0% to 70%. A linear regression model revealed that a stay in the nursing home of longer than 6 months and accommodation in a room with 3 or more beds were positively associated with the transmission rate. Receipt of antibiotics during the 4 weeks preceding the study was negatively associated with transmission. CONCLUSIONS Stays beyond 6 months and accommodation in rooms with multiple beds are important for the transmission of S. aureus. One way to reduce transmission would be to design facilities with single and double rooms. However, the social needs of the residents must be evaluated and respected.

Life-threatening infection with multiresistant Staphylococcus epidermidis in a patient with end-stage renal disease: cure with chloramphenicol and quinupristin/dalfopristin (RP 59500).

SummaryA 45-year-old man with end-stage renal disease underwent a cadaveric kidney transplantation. The allograft had to be removed 10 days after transplantation because of an acute vascular rejection. After explantation, the patient suffered from a life-threatening infection withStaphylococcus epidermidis involving lungs, eyes and liver for 11 months. Despite adequate therapy including vancomycin followed by teicoplanin, he developed spondylodiscitis requiring repeated surgical interventions. The definitive cure was achieved by a sequential therapy with chloramphenicol and quinupristin/dalfopristin.

Multilevel Epidural Abscess Formation with Paraplegia in a Healthy 33-Year-Old Man Caused by Staphylococcus aureus (MSSA)

Abstract.We report an unusual case of a devastating multilevel pyogenic spondylitis with paraplegia and soft tissue abscess formation in a previously healthy young man. Methicillin susceptible Staphylococcus aureus (MSSA) was identified as causal pathogen. The infection could only be managed after surgical debridement of all spinal manifestations and a prolonged course of antibiotic therapy. It is possible that delayed surgical debridement of all infection sites fostered the course of the disease.

Bacterial aetiology and mortality in COPD patients with CAP: results from the German Competence Network, CAPNETZ

BACKGROUND Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality, and chronic obstructive pulmonary disease (COPD) is a frequent comorbidity. The bacterial aetiology of CAP-COPD and its possible associations with serum markers and mortality are incompletely understood. OBJECTIVES 1) To assess the bacterial aetiology of CAP only and CAP-COPD, and 2) to study the association between bacterial aetiology, empirical antibiotic treatment, serum markers and mortality. METHODS Of 1288 patients with CAP (57.0% males, age 59.0 years ± 18.5), 262 (20.3%) fulfilled the diagnostic criteria for COPD. Differences between subgroups were investigated using univariate analyses and corrected for multiple comparisons. RESULTS Streptococcus pneumoniae was the most common pathogen (30.8% CAP only vs. 26.0% CAP-COPD, not significant). Haemophilus influenzae was significantly more frequent in CAP-COPD (5.6% CAP only vs. 26.0% CAP-COPD, P < 0.001). The number given adequate empirical antibiotic treatment was comparable (83.3% CAP only vs. 83.6% CAP-COPD, P > 0.05). The CAP-COPD group had worse CURB-65 and partial pressure of arterial oxygen levels than the CAP only group (P < 0.001). Partial pressure of arterial carbon dioxide levels were increased in CAP-COPD patients without pathogen detection (P < 0.001). Short- (P = 0.011) and long-term mortality (P = 0.006) were highest in CAP-COPD without pathogen detection. CONCLUSION It is important to identify COPD patients with CAP. In particular, those without bacterial pathogen detection have more severe CAP and are at higher risk of dying. Better understanding of the aetiology could contribute to improved management and treatment of CAP in COPD patients.