Evaluation of the TPX MRSA assay for the detection of methicillin-resistant Staphylococcus aureus.

The aim of this study was to evaluate a new type of assay for the phenotypic detection of methicillin-resistant Staphylococcus aureus (MRSA). The assay is based on a point-of-care compatible two-photon excitation fluorescence detection technology (TPX). A collection of 243 epidemic MRSA isolates was tested in addition to 138 sporadic MRSA and 101 negative control strains. The assay proved to be both sensitive (97.9%) and specific (94.1%) in the identification of MRSA, with adequate positive (98.4%) and negative (92.2%) predictive values. The time required for obtaining a positive test result was less than 14 h for 99.0% of the MRSA true-positive samples. After a test run, the selectively enriched reaction mixtures may be recovered and further studied by molecular or standard phenotypic methods. The main benefits of the TPX methodology include a simple assay procedure, low reagent consumption, and a high-throughput capacity.

Utility of C-reactive protein in assessing the disease severity and complications of community-acquired pneumonia.

Previous studies on the usefulness of C-reactive protein (CRP) in patients with community-acquired pneumonia (CAP) have yielded somewhat inconsistent results. Our aim was to assess the value of CRP in estimating the severity and complications of CAP. CRP levels during the first 5 days of hospitalization were measured in 384 adult patients with CAP, and the data were evaluated using comprehensive statistical analyses. Significantly higher CRP levels on admission were detected in Pneumonia Severity Index (PSI) classes III-V than in classes I and II (p <0.001). An increment of 50 mg/L CRP on admission was associated with a 1.22-fold odds for a patient to be in PSI classes III-V as compared with classes I and II (OR 1.22, 95% CI 1.11-1.34; p <0.001). CRP levels were significantly higher in bacteraemic pneumonia than in non-bacteraemic pneumonia (p <0.001). An increment of 50 mg/L CRP was associated with a 1.67-fold odds for a patient to be bacteraemic (OR 1.67, 95% CI 1.46-1.92; p <0.001). CRP levels >100 mg/L on day 4 after the admission were significantly associated with complications (p <0.01). There was a trend for an association between the level of CRP on admission and the time to reach clinical stability (p <0.01). In conclusion, CRP may be valuable for revealing the development of complications in CAP. It may also be useful to assess the disease severity, thus being complementary to the assessment of the PSI. In our patients, high CRP levels were associated with a failure to reach clinical stability.

Infective endocarditis in a Finnish teaching hospital: a study on 326 episodes treated during 1980-2004.

OBJECTIVES: To evaluate potential changes of infective endocarditis (IE) in patients treated in a Finnish teaching hospital during the past 25 years. PATIENTS: 326 episodes of IE in 303 patients treated during 1980-2004 were evaluated for clinical characteristics and their changes over time. RESULTS: The mean age of the patients increased with time (from 47.2 to 54.5 years, p = 0.003). Twenty-five (7.7%) episodes were associated with intravenous drug use (IVDU), with a significant increase of these episodes after 1996 (from 0 to 19 (20%), p < 0.001). Viridans streptococci were the most common causative agents of IE during 1980-1994, but after that Staphylococcus aureus was the most common pathogen (p = 0.015). The proportion of IE of the aortic valve decreased during the study (from 30 (49%) to 26 (27%), whereas the proportions of mitral (11 (18%) to 33 (35%) and tricuspid valve IE (0 to 13 (14%) increased correspondingly (p = 0.001). This was mainly due to more patients with IVDU. Chronic dialysis for renal failure as an underlying condition increased over time (from 0 to 7 (7.4%), p = 0.015) but no other predisposing conditions changed. Complications such as neurological manifestations and heart failure did not change in frequency, but the incidence of lung emboli increased (from 0% to 10.5%, p < 0.001); 83% of these emboli occurred in patients with IVDU. The proportion of patients requiring surgical treatment and mortality due to IE did not change. CONCLUSIONS: During these 25 years, the causative agents, affected valves and complications of IE changed to some degree. These changes were mainly attributed to the increase of IVDU-associated IE. Except for the increase in age, the clinical presentation and outcome in non-addicts remained substantially unchanged.

Etiology of aseptic meningitis and encephalitis in an adult population.

OBJECTIVE: To investigate the etiology of aseptic meningitis and encephalitis in an adult population using modern microbiologic methods. METHODS: Consecutive patients (ages > or =16) with aseptic meningitis or encephalitis treated in Turku University Hospital, Finland, during 1999 to 2003 were included in the study. Microbiologic tests were performed, including CSF PCR tests for enteroviruses, herpes simplex virus (HSV) 1, HSV-2, and varicella zoster virus (VZV), as well as serum and CSF antibody analysis for these viruses. Antibody testing was also performed for other pathogens commonly involved in neurologic infections. Virus culture was performed on CSF, fecal, and throat swab specimens. RESULTS: Etiology was defined in 95 of 144 (66%) patients with aseptic meningitis. Enteroviruses were the major causative agents (26%), followed by HSV-2 (17% of all, 25% of females) and VZV (8%). Etiology was identified in 15 of 42 (36%) patients with encephalitis, VZV (12%), HSV-1 (9%), and tick-borne encephalitis virus (9%) being the most commonly involved pathogens. Etiologic diagnosis was achieved by PCR in 43% of the patients with meningitis and in 17% of those with encephalitis. CONCLUSIONS: Enteroviruses and HSV-2 are the leading causes of adult aseptic meningitis, and PCR is of diagnostic value. However, in most cases of encephalitis, the etiology remains undefined.

Levofloxacin does not decrease mortality in Staphylococcus aureus bacteraemia when added to the standard treatment: a prospective and randomized clinical trial of 381 patients.

OBJECTIVES: To study whether levofloxacin, added to standard treatment, could reduce the high mortality and complication rates in Staphylococcus aureus bacteraemia. DESIGN: A prospective randomized multicentre trial from January 2000 to August 2002. SETTING: Thirteen tertiary care or university hospitals in Finland. SUBJECTS: Three hundred and eighty-one adult patients with S. aureus bacteraemia. Patients with meningitis, and those with fluoroquinolone- or methicillin-resistant S. aureus were excluded. INTERVENTIONS: Standard treatment (mostly semisynthetic penicillin) (n = 190) or that combined with levofloxacin (n = 191). Supplementary rifampicin was recommended if deep infection was suspected. MAIN OUTCOME MEASURES: Primary end-points were mortality at 28 days and at 3 months. Clinical and laboratory parameters were analysed as secondary end-points. RESULTS: Adding levofloxacin to the standard treatment offered no survival benefit. Case fatality rates were 14% in both groups at 28 days, and 21% in the standard treatment and 18% in the levofloxacin group at 3 months. Levofloxacin combination did not differ from the standard treatment in the number of complications, time to defervescence, decrease in serum C-reactive protein concentration or length of antibiotic treatment. Deep infection was found in 84% of patients within 1 week following randomization with no difference between the treatment groups. At 3 months, the case fatality rate for patients with deep infection was 17% amongst those who received rifampicin versus 38% for those without rifampicin (P < 0.001, odds ratio = 3.06, 95% confidence intervals = 1.69-5.54). CONCLUSIONS: Levofloxacin combined with standard treatment in S. aureus bacteraemia did not decrease mortality or the incidence of deep infections, nor did it speed up recovery. Interestingly, deep infections in S. aureus bacteraemia appeared to be more common than previously reported.

Bronchoalveolar lavage in immunocompromised patients with haematological malignancy--value of new microbiological methods.

PURPOSE: To assess the usefulness of new culture-independent microbiological methods to analyse bronchoalveolar lavage (BAL) fluid from haematological patients with clinical pneumonia. PATIENTS AND METHODS: Results of 135 BALs from 122 disease episodes in 99 patients treated between 1996 and 2002 were retrospectively analysed. Forty-three patients had undergone haematopoietic stem cell transplantation and 56 patients had been treated with conventional chemotherapy for haematological malignancy. In addition to conventional microbiological methods, polymerase chain reaction (PCR) tests for Pneumocystis carinii, cytomegalovirus (CMV), Legionella sp., mycobacterium, Mycoplasma pneumoniae, and Chlamydia pneumoniae and the Aspergillus antigen test were performed. RESULTS: Three (2.2%) quantitative and four (3.0%) special bacterial cultures gave an aetiological diagnosis. A respiratory virus was isolated in 10 episodes (8.2%). The diagnostic yield increased to 35.6% (48 of 135) by other methods. The P. carinii PCR test was positive in 21 of 24 patients with P. carinii pneumonia, being the only microbiological indication of P. carinii in four cases. The CMV PCR test was positive in 18 patients, but in 14 patients the clinical significance of the finding remained unproven. The Aspergillus antigen test was positive in seven of nine patients with aspergillosis, being the only microbiological indication of Aspergillus in three cases. The result of BAL indicated commencement of specific antimicrobial treatment in 27 episodes (22.1%). CONCLUSION: The contribution of new culture-independent methods to the total diagnostic yield was of note. Among these methods, the P. carinii PCR and Aspergillus antigen tests proved the most valuable, while the CMV PCR test was not clinically useful.

Aetiological diagnosis of brain abscesses and spinal infections: application of broad range bacterial polymerase chain reaction analysis.

OBJECTIVE: To evaluate the usefulness of the broad range bacterial rDNA polymerase chain reaction (PCR) method combined with DNA sequencing in the aetiological diagnosis of intracranial or spinal infections in neurosurgical patients. METHODS: In addition to conventional methods, the broad range bacterial PCR approach was applied to examine pus or tissue specimens from cerebral or spinal lesions in patients treated in a neurosurgical unit for a clinical or neuroradiological suspicion of bacterial brain abscess or spondylitis. RESULTS: Among the 44 patients with intracranial or spinal lesions, the final diagnosis suggested bacterial disease in 25 patients, among whom the aetiological agent was identified in 17. A causative bacterial species was identified only by the rDNA PCR method in six cases, by both the PCR methodology and bacterial culture in six cases, and by bacterial culture alone in five. All samples in which a bacterial aetiology was identified only by the PCR approach were taken during antimicrobial treatment, and in three patients the method yielded the diagnosis even after >/= 12 days of parenteral treatment. One case also identified by the PCR approach alone involved a brain abscess caused by Mycoplasma hominis, which is not readily cultured by routine methods. CONCLUSIONS: In patients with brain abscesses and spinal infections, the broad range bacterial rDNA PCR approach may be the only method to provide an aetiological diagnosis when the patient is receiving antimicrobial treatment, or when the causative agent is fastidious.

Presence of parvovirus B19 DNA in chronic urticaric and healthy human skin.

BACKGROUND: The etiology of chronic urticaria is undefined, but the potential role of infectious agents as one triggering factor has been suggested. The appearance of chronic urticaria in a 16-year old male after a history of a recent parvovirus B19 (B19) infection led us to investigate the association between B19 and chronic urticaria. OBJECTIVES: To investigate whether parvovirus B19 (B19) has a role in chronic urticaria. STUDY DESIGN: We amplified B19 DNA from skin biopsy samples of 36 adult chronic urticaria patients as well as of 22 healthy controls using two sets of separate primers and probe. Circulating IgG and IgM antibodies to B19 were measured from 27 patients and from all controls. RESULTS: B19 DNA was detected in 18 (50%) skin biopsy samples of 36 patients with chronic urticaria. Unexpectedly, also 14 (64%) skin biopsy samples from 22 healthy controls harbored B19 DNA. All 32 persons with positive B19 PCR findings had circulating IgG-class antibodies to B19 major structural protein VP2, but no IgM antibodies. CONCLUSION: Our results show that B19 DNA commonly exists in human skin. Therefore, the association between B19 infection and chronic urticaria remains uncertain. However, these findings raise the question whether the skin may constitute a reservoir for B19.

Reduced fluoroquinolone susceptibility in Salmonella enterica serotypes in travelers returning from Southeast Asia.

During 1995 to 1999, we collected 1,210 Salmonella isolates; 629 were from Finnish travelers returning from abroad. These isolates were tested for susceptibility by determining MICs to ciprofloxacin, nalidixic acid, and seven additional antimicrobial agents. From 1995 to 1999, the annual proportion of reduced ciprofloxacin susceptibility (MIC > 0.125 microg/mL) among all travelers' isolates increased from 3.9% to 23.5% (p<0.001). The increasing trend was outstanding among the isolates from Southeast Asia; isolates from Thailand alone increased from 5.6% to 50.0% (p<0.001). The reduced fluoroquinolone susceptibility was nonclonal in character and significantly associated with multidrug resistance. A point mutation in the quinolone resistance-determining region of gyrA was present in all isolates with reduced susceptibility. These data provide further evidence for the rapid spread of multidrug-resistant pathogens from one continent to another.

Infrequent isolation of multiresistant Acinetobacter baumannii from the staff tending a colonized patient with severe burns.

A patient with severe burns who was colonized by multiresistant Acinetobacter baumannii was cared for in contact isolation by staff intensively trained on hospital hygiene. Of the 1,907 postexposure cultures from the staff and 425 environmental samples, only 0.7% and 4%, respectively, yielded this microorganism. These data show that strict hygienic measures may limit staff colonization and contamination of the environment byA baumannii.

Macrolide-resistant Streptococcus pneumoniae and use of antimicrobial agents.

The prevalence of isolates of Streptococcus pneumoniae (pneumococcus) that are resistant to antimicrobial agents is increasing globally. We studied the connection between antimicrobial resistance of pneumococci and regional use of antimicrobial agents in Finland. In 1997, a total of 6106 pneumococcal isolates were identified in clinical microbiology laboratories in Finland. Most of the pneumococci were isolated from respiratory tract samples, 8% were from blood culture samples, and 0.5% were from cerebrospinal fluid samples. The regional levels of resistance for pneumococci in 1997 were compared with the regional rates of use of antimicrobial agents from 1995 through 1996. We found that resistance to macrolides correlated highly significantly with macrolide use (P=.006). A significant correlation was also found between resistance to trimethoprim-sulfamethoxazole and trimethoprim-sulfamethoxazole use (P=.043). We did not find a correlation between penicillin resistance and the use of any antimicrobial agent. The positive correlation between macrolide-resistant pneumococci and the use of macrolides is worrying, because macrolides are used worldwide in the treatment of patients with respiratory tract infections, which are often caused by pneumococci.

Eradication of methicillin-resistant Staphylococcus aureus from a health center ward and associated nursing home.

BACKGROUND: Long-term health care facilities have been recognized as reservoirs of multiresistant bacterial strains, especially methicillin-resistant Staphylococcus aureus (MRSA). Efforts to control MRSA in this setting usually have been only partially effective. We describe herein the eradication of epidemic MRSA from a Finnish health care center ward and affiliated nursing home. METHODS: The methods to control MRSA included (1) contact isolation precautions, (2) screening for asymptomatic carriage, (3) eradication of carriage, and (4) education of staff on hygienic measures. The first 6 patients with MRSA-positive findings were referred without delay to the Infectious Diseases Unit of the adjacent university hospital for eradication treatment. Later, an isolation unit of 6 rooms was founded in the health care center, where the MRSA-colonized patients were nursed as a separate cohort until they, in succession, were referred to the Infectious Diseases Unit for decolonization. RESULTS: From May 20 through August 17, 1993, the epidemic MRSA strain was isolated from 8 long-term patients on the 40-bed ward of the health care center, 4 of the 59 residents of the nursing home, and 1 member of the staff. Eradication of carriage was successful in all except 1 patient with dementia, who was nursed in contact isolation in the health care center until his death 21 months later. CONCLUSIONS: It is possible to eradicate MRSA from a long-term health care facility even after 13 cases by applying strict control measures. Our experience may be valuable in the future decision-making process for control of new and more challenging multiresistant bacteria, eg, vancomycin-resistant strains of MRSA.

Parainfluenza virus type 3 infections in a hematology unit.

Parainfluenza virus type 3 (PIV3) is associated with a high mortality rate in BMT recipients with lower respiratory tract infections. We describe nine patients with hematological malignancies (five having undergone either allogeneic or autologous stem cell transplantation) identified as having PIV3 infection during a 2-month period in a Hematology Unit. Four patients with infiltrates on chest radiograph received intravenous ribavirin therapy; all survived. The infection was community-acquired in two patients, while nosocomial origin of the disease was evident, or presumed, in the remaining seven. The policy implemented to control the spread of PIV3 was as follows: (1) nasopharyngeal samples for antigen detection were obtained from all patients presenting with respiratory symptoms; (2) all diagnosed (or suspected) PIV3-positive hematological patients were nursed following contact isolation precautions, preferably in the Infectious Diseases Unit; and (3) staff were given further education on hospital hygiene. Our experience shows that it may be possible to avoid mortality for PIV3 lower respiratory tract infection in immunocompromised patients by early commencement of intravenous ribavirin. It is also possible, even without closing the ward, to contain nosocomial spread of PIV3 by implementing systematic nasopharyngeal sampling for rapid diagnostics, and by strict adherence to cohorting and contact isolation precautions.

Neurologic manifestations of infective endocarditis: a 17-year experience in a teaching hospital in Finland.

BACKGROUND: Many previous studies have endeavored to find appropriate means to reduce the occurrence of neurologic manifestations in patients with infective endocarditis (IE). We evaluated patients with IE-associated neurologic complications and compared them with patients with IE who did not have neurologic symptoms. Particular attention was focused on assessing the impact of cardiac surgery and the presence of potential risk factors for complications on the outcome of the patients. METHODS: A total of 218 episodes designated as definite or possible IE according to Duke criteria and treated during the years 1980 through 1996 in a Finnish teaching hospital were retrospectively evaluated for neurologic manifestations. RESULTS: Neurologic complications were identified in 55 episodes (25%), with an embolic event as the most frequent manifestation (23/55; 42%). In the majority (76%) of episodes, the neurologic manifestation was evident before antimicrobial treatment was started, being the first sign of IE in 47% of episodes. Only 1 recurrent cerebral embolization was observed. Neurologic complications were significantly associated with Staphylococcus aureus infection (29% vs 10%; P =.001) and with IE affecting both the aortic and the mitral valves (56% vs 23%; P<.01), but not with echocardiographic detection of vegetations or anticoagulant therapy. Death during the acute phase of IE occurred in 13 episodes (24%) with neurologic complications and in 17 episodes (10%) without neurologic complications (P<.03). In episodes with neurologic complications, the IE-associated mortality rate was 25% (10/40) in the medical treatment group and 20% (3/15) in the surgical group. No neurologic deterioration was observed in these surgically treated patients postoperatively. CONCLUSIONS: Our results reinforce the belief that rapid diagnosis and initiation of antimicrobial therapy may still be the most effective means to prevent neurologic complications. These data underscore the importance of diagnostic alertness to the prognosis of patients with IE.