Clinical evaluation of commercial nucleic acid amplification tests in patients with suspected sepsis.

BACKGROUND: Sepsis is a serious medical condition requiring timely administered, appropriate antibiotic therapy. Blood culture is regarded as the gold standard for aetiological diagnosis of sepsis, but it suffers from low sensitivity and long turnaround time. Thus, nucleic acid amplification tests (NAATs) have emerged to shorten the time to identification of causative microbes. The aim of the present study was to evaluate the clinical utility in everyday practice in the emergency department of two commercial NAATs in patients suspected with sepsis. METHODS: During a six-week period, blood samples were collected consecutively from all adult patients admitted to the general emergency department for suspicion of a community-onset sepsis and treated with intravenous antibiotics. Along with conventional blood cultures, multiplex PCR (Magicplex™) was performed on whole blood specimens whereas portions from blood culture bottles were used for analysis by microarray-based assay (Prove-it™). The aetiological significance of identified organisms was determined by two infectious disease physicians based on clinical presentation and expected pathogenicity. RESULTS: Among 382 episodes of suspected sepsis, clinically relevant microbes were detected by blood culture in 42 episodes (11%), by multiplex PCR in 37 episodes (9.7%), and by microarray in 32 episodes (8.4%). Although moderate agreement with blood culture (kappa 0.50), the multiplex PCR added diagnostic value by timely detection of 15 clinically relevant findings in blood culture-negative specimens. Results of the microarray corresponded very well to those of blood culture (kappa 0.90), but were available just marginally prior to blood culture results. CONCLUSIONS: The use of NAATs on whole blood specimens in adjunct to current culture-based methods provides a clinical add-on value by allowing for detection of organisms missed by blood culture. However, the aetiological significance of findings detected by NAATs should be interpreted with caution as the high analytical sensitivity may add findings that do not necessarily corroborate with the clinical diagnosis.

Faecal microbiota transplantation and bacteriotherapy for recurrent Clostridium difficile infection: a retrospective evaluation of 31 patients.

BACKGROUND: Recurrent Clostridium difficile infection (CDI) is a significant problem due to its increased incidence and severity. Failure rates for standard antibiotic therapies are high. In our hospital, faecal microbiota transplantation (FMT), or instillation of a culture mixture of known enteric bacteria in saline as rectal bacteriotherapy (RBT), has long been used as 'rescue therapy' in patients with recurrent disease, in whom repeated courses of standard antibiotic treatment have failed. We wanted to evaluate the effectiveness of FMT and RBT for recurrent CDI. METHODS: The records of 31 patients treated with either FMT or RBT for recurrent CDI were reviewed retrospectively. FMT was based on faecal donation by a close relative and RBT on a defined saline mixture of 10 individually cultured enteric bacterial strains originally isolated from healthy persons. Both types of instillation were carried out through a rectal catheter. FMT (500 ml) was given as 1 installation. RBT (200 ml) was given as 2 or 3 installations with an interval of 2 days between courses. Treatment success was defined as a sustained loss of symptoms and discontinuation of diarrhoea within 3 days. RESULTS: Of 31 patients, 23 (74%) responded successfully to the treatment: 16 of 23 (70%) receiving FMT and 7 of 8 (88%) receiving RBT. CONCLUSION: We found FMT to be effective in patients with recurrent CDI. RBT based on a predefined bacterial suspension was as effective as or better than FMT based on faecal donation; however, multiple installations may be needed.

Legionnaires' disease from a cooling tower in a community outbreak in Lidköping, Sweden- epidemiological, environmental and microbiological investigation supported by meteorological modelling.

BACKGROUND: An outbreak of Legionnaires' Disease took place in the Swedish town Lidköping on Lake Vänern in August 2004 and the number of pneumonia cases at the local hospital increased markedly. As soon as the first patients were diagnosed, health care providers were informed and an outbreak investigation was launched. METHODS: Classical epidemiological investigation, diagnostic tests, environmental analyses, epidemiological typing and meteorological methods. RESULTS: Thirty-two cases were found. The median age was 62 years (range 36 - 88) and 22 (69%) were males. No common indoor exposure was found. Legionella pneumophila serogroup 1 was found at two industries, each with two cooling towers. In one cooling tower exceptionally high concentrations, 1.2 × 109 cfu/L, were found. Smaller amounts were also found in the other tower of the first industry and in one tower of the second plant. Sero- and genotyping of isolated L. pneumophila serogroup 1 from three patients and epidemiologically suspected environmental strains supported the cooling tower with the high concentration as the source. In all, two L. pneumophila strains were isolated from three culture confirmed cases and both these strains were detected in the cooling tower, but one strain in another cooling tower as well. Meteorological modelling demonstrated probable spread from the most suspected cooling tower towards the town centre and the precise location of four cases that were stray visitors to Lidköping. CONCLUSIONS: Classical epidemiological, environmental and microbiological investigation of an LD outbreak can be supported by meteorological modelling methods.The broad competence and cooperation capabilities in the investigation team from different authorities were of paramount importance in stopping this outbreak.

Febrile reactions after transrectal ultrasound-guided prostatic biopsy: a retrospective study.

OBJECTIVE: The aim of this study was to evaluate the incidence and clinical presentation in patients with hospital admission owing to febrile infections after transrectal ultrasound-guided prostate biopsies. MATERIAL AND METHODS: The case histories of the 57 patients (3.5%) who, between January 2006 and December 2009, were admitted owing to a febrile infection secondary to the 1633 transrectal prostate biopsies performed during the period were retrospectively analysed. Norfloxacin 400 mg ? 2 was given for 3 days as prophylaxis starting just before or within 10 min of biopsy. RESULTS: Quinolone-resistant Escherichia coli was isolated from blood cultures in 43% of the patients (n = 15) presenting with fever between 24 and 48 h postbiopsy. The urine culture was positive in 13% and no patient had symptoms suggestive of a urinary tract infection (UTI). In patients presenting after 48 h (n = 42), quinolone-resistant E. coli was never isolated from blood; E. coli was cultured from urine in 45% of the patients and in 48% it was associated with UTI symptoms. CONCLUSIONS: The finding that early postbiopsy fever was often associated with a quinolone-resistant E. coli bacteraemia and never with UTI symptoms, as opposed to late-onset fever, where such symptoms were common and quinolone-resistant E. coli was rarely detected, suggests divergent pathogenic mechanisms underpinning early- and late-onset febrile reactions. These findings have implications for how antibiotic prophylaxis should be given.

Urine cultures from indwelling bladder catheters in nursing home patients: a point prevalence study in a Swedish county.

OBJECTIVES: To survey the bacterial flora and antibiotic resistance in urinary strains from patients with indwelling bladder catheters residing in nursing homes within a geographically defined region. MATERIAL AND METHODS: Urine was sampled for culture from 163 catheter patients (126 men and 37 women) during a 2 week period in March 2010. Susceptibility testing of the isolated bacteria was compared with all urinary strains (n = 9994) from hospitals and primary healthcare in the same geographical area cultured during the first 6 months of 2010 (control group). RESULTS: Bacteriuria was found in 159 of 163 urine samples (98%). Enterococcus faecalis and Escherichia coli were the most common species, one or both being detected in 72% of the urine samples, while Proteus species were found in10% and a single isolate of Providentia species was seen.Strains in the study patients were more resistant to antibiotics than in the control group. Particularly large differences were noted for ciprofloxacinin in E. coli (16.9% vs 7.9%) and for trimethoprim-sulfamethoxazole in E. faecalis (39.1% vs 24.8%). One extended spectrum ß-lactamase (ESBL)-producing E. coli was cultured (1.3%), compared with 1.6% in the control group. No vancomycin-resistant enterococci (VRE) or methicillin-resistant Staphylococcus aureus (MRSA) were detected. CONCLUSIONS: Proteus mirabilis and Providentia species were rarely isolated, in sharp contrast to previous studies from geriatric hospital wards where they have often been in the majority. The limited incidence of ESBL and the absence of VRE and MRSA is gratifying, but the high resistance to antibiotics needs to be assessed on a continuous basis.

Antimicrobial susceptibility of invasive pneumococcal isolates from a region in south-west Sweden 1998-2001.

Invasive disease caused by antibiotic resistant pneumococci is a worldwide problem. All invasive pneumococcal strains in an area of south-west Sweden with 1.7 million inhabitants were collected prospectively during 1998-2001. Minimum inhibitory concentrations (MICs) were determined by E-test and correlated to serotypes and clinical characteristics. Of 827 strains, 744 (90%) were susceptible (S) to all agents tested and 83 (10%) were indeterminate (I) or resistant (R) to at least 1 agent. 22 isolates (2.7%) were I to penicillin (MIC >0.06 to < or = 1.0 mg/l), but none were R (MIC >1.0 mg/l). Numbers and proportions of decreased susceptibility against other agents tested were as follows: erythromycin R: 30 (3.6%), clindamycin R: 6 (0.7%), tetracycline R: 16 (1.9%), moxifloxacin R: 1 (0.1%), cotrimoxazole I: 17 (2%) and R: 31(4%). Non-susceptibility to at least 1 agent was not correlated with age, clinical manifestation, underlying diseases and outcome. The serotype distribution differed between non-susceptible and susceptible strains. The serotypes in the 7-valent pneumococcal conjugate vaccine covered 42% of all infections and 73% of those caused by non-susceptible strains. In conclusion, the impact of antibiotic resistance in invasive pneumococcal disease remains limited in south-west Sweden.

A community outbreak of Legionnaires' disease from an industrial cooling tower: assessment of clinical features and diagnostic procedures.

An outbreak of Legionnaires' disease (LD) occurred in Lidköping, Sweden, in August 2004. A cooling tower was identified as the probable source of infection. During the outbreak period an unexpected 3-6-fold increase in pneumonia patients was noted at the local hospital. During 7 weeks LD was diagnosed in 15 patients by urinary antigen and/or sputum culture. Additionally, 15 LD patients were diagnosed later by serology. Patients with LD were generally younger, more healthy, and more often smokers compared to other pneumonia patients. On admittance they had more severe symptoms with high fever and raised CRP levels, and more often hyponatraemia, gastrointestinal and CNS symptoms. A causative agent besides Legionella was found in 2 patients only. A significant titre rise for Mycoplasma and/or Chlamydophila pneumoniae was found in 13 of 29 tested patients with confirmed LD. We conclude that the clinical diagnosis of LD is difficult and that available diagnostic methods detect only a minority of patients in the acute phase. Therefore in severe pneumonia, empirically targeted therapy should be instituted on clinical grounds irrespective of the results of diagnostic tests. The observation of increased antibody levels for M. and C. pneumoniae suggests an unspecific immune reaction and merits further study.