Mucosal-associated invariant T cells and Vδ2+ γδ T cells in community acquired pneumonia: association of abundance in sputum with clinical severity and outcome.

Mucosal-associated invariant T (MAIT) cells and Vδ2+ γδ T cells are anti-bacterial innate-like lymphocytes (ILLs) that are enriched in blood and mucosa. ILLs have been implicated in control of infection. However, the role of ILLs in community-acquired pneumonia (CAP) is unknown. Using sputum samples from a well-characterized CAP cohort, MAIT cell and Vδ2+ T cell abundance was determined by quantitative polymerase chain reaction (qPCR). Cytokine and chemokine concentrations in sputum were measured. The capacity of bacteria in sputum to produce activating ligands for MAIT cells and Vδ2+ T cells was inferred by 16S rRNA sequencing. MAIT cell abundance in sputum was higher in patients with less severe pneumonia; duration of hospital admission was inversely correlated with both MAIT and Vδ2+ T cell abundance. The abundance of both ILLs was higher in patients with a confirmed bacterial aetiology; however, there was no correlation with total bacterial load or the predicted capacity of bacteria to produce activating ligands. Sputum MAIT cell abundance was associated with interferon (IFN)-α, IFN-γ, and sputum neutrophil abundance, while Vδ2+ T cell abundance was associated with CXCL11 and IFN-γ. Therefore, MAIT and Vδ2+ T cells can be detected in sputum in CAP, where they may contribute to improved clinical outcome.

Multidrug resistant Enterobacteriaceae in New Zealand: a current perspective.

In this article we review mechanisms and potential transmission pathways of multidrug resistance in Enterobacteriaceae, with an emphasis on extended-spectrum ß-lactamase (ESBL)-production. This provides background to better understand challenges presented by this important group of antimicrobial resistant bacteria, and inform measures aimed at prevention and control of antimicrobial resistance in general. Humans and animals interact at various levels; household pets cohabit with humans, and other animals interact with people through direct contact, as well as through the food chain and the environment. These interactions offer opportunity for bacteria such as ESBL-producers to be shared and transmitted between species and, in turn, increase the risk of zoonotic and reverse-zoonotic disease transmission. A key step in curtailing antimicrobial resistance is improved stewardship of antimicrobials, including surveillance of their use, better infection-control and prevention, and a better understanding of prescribing practice in both veterinary and medical professions in New Zealand. This will also require prospective observational studies to examine risk factors for antimicrobial resistance. Due to the interconnectedness of humans, animals and the environment actions to effect the changes required should be undertaken using a One Health approach.

Effect of vitamin D3 supplementation on Staphylococcus aureus nasal carriage: a randomized, double-blind, placebo-controlled trial in healthy adults.

Observational studies have reported an inverse association between serum 25-hydroxyvitamin D (25OHD) concentrations and Staphylococcus aureus nasal carriage; however, clinical trials of vitamin D supplementation are lacking. To assess the effect of vitamin D3 supplementation on persistent S. aureus nasal carriage we conducted a randomized, double-blind, placebo-controlled trial among 322 healthy adults. Participants were given an oral dose of either 200 000 IU vitamin D3 for each of 2 months, followed by 100 000 IU monthly or placebo in an identical dosing regimen, for a total of 18 months. Nasal swabs for S. aureus culture and serum for 25OHD measurement were obtained at baseline, 6, 12 and 18 months of study. The mean baseline concentration of 25OHD was 72 nM (SD 22 nM). Vitamin D3 supplementation increased 25OHD levels which were maintained at >120 nM throughout the study. Nasal colonization by S. aureus was found in 31% of participants at baseline. Persistent carriage, defined as those that had positive S. aureus nasal cultures for all post-baseline swabs, occurred in 20% of the participants but vitamin D3 supplementation was not associated with a reduction in persistent carriage (OR = 1.39, 95% CI 0.63-3.06). Risk factor analysis showed that only gender was significantly associated with carriage, where women were less likely to be carriers than men (relative risk 0.83, 95% CI 0.54-0.99). Serum 25OHD concentrations were not associated with the risk of carriage. In conclusion, monthly administration of 100 000 IU of vitamin D3 did not reduce persistent S. aureus nasal carriage.

Canterbury Health, Ageing and Life Course (CHALICE) study: rationale, design and methodology.

AIMS: New Zealand's ageing population threatens the financial sustainability of our current model of health service delivery. The Canterbury Health, Ageing and Life Course (CHALICE) study aims to develop a comprehensive and flexible database of important determinants of health to inform new models. This paper describes the design, methodology, and first 300 participants of CHALICE. METHODS: Commencing August 2010, CHALICE is a multidisciplinary prospective random cohort study and biobank of 1,000 Canterbury adults aged 49-51 years at inception, stratified by self-identified Maori (n=200) and non-Maori (n=800) ethnicity. Assessment covers sociodemographic, physical, cognition, mental health, clinical history, family and social, cardiovascular, and lifestyle domains. Detailed follow-up assessment occurs every 5 years, with a brief postal follow-up assessment undertaken annually. RESULTS: For the first 300 participants (44 Maori, 256 non-Maori), the participation rate is 63.7%. Overall, 53.3% of participants are female, 75.3% are living in married or de facto relationships, and 19.0% have university degrees. These sociodemographic profiles are comparable with the 2006 Census, Canterbury region, 50-54 years age group percentages (50.7%, 77.2%, and 14.3%, respectively). CONCLUSIONS: CHALICE has been designed to provide quality data that will inform policy development and programme implementation across a broad spectrum of health indicators.

Haemophilus influenzae type b carriage and novel bacterial population structure among children in urban Kathmandu, Nepal.

Haemophilus influenzae type b (Hib) is a major cause of invasive bacterial infection in children that can be prevented by a vaccine, but there is still uncertainty about its relative importance in Asia. This study investigated the age-specific prevalence of Hib carriage and its molecular epidemiology in carriage and disease in Nepal. Oropharyngeal swabs were collected from children in Kathmandu, Nepal, from 3 different settings: a hospital outpatient department (OPD), schools, and children's homes. Hib was isolated using Hib antiserum agar plates, and serotyping was performed with latex agglutination. Hib isolates from children with invasive disease were obtained during active microbiological surveillance at Patan Hospital, Kathmandu, Nepal. Genotyping of disease and carriage isolates was undertaken using multilocus sequence typing (MLST). Swabs were taken from 2,195 children, including 1,311 children at an OPD, 647 children attending schools, and 237 children in homes. Overall, Hib was identified in 5.0% (110/2,195; 95% confidence interval [95% CI], 3.9% to 6.4%). MLST was performed on 108 Hib isolates from children carrying Hib isolates and 15 isolates from children with invasive disease. Thirty-one sequence types (STs) were identified, and 20 of these were novel STs. The most common ST isolates were sequence type 6 (ST6) and the novel ST722. There was marked heterogeneity among the STs from children with disease and children carrying Hib. STs identified from invasive infections were those commonly identified in carriage. This study provides evidence of Hib carriage among children in urban Nepal with genetically diverse strains prior to introduction of universal vaccination. The Hib carriage rate in Nepal was similar to the rates observed in other populations with documented high disease rates prior to vaccination, supporting implementation of Hib vaccine in Nepal in 2009.

Clinical profile of invasive pneumococcal diseases in Patan Hospital, Nepal.

BACKGROUND: Pneumococcal infection is one of the leading causes of pneumonia, meningitis and septicemia in developing countries. It accounts for one million deaths each year in children. OBJECTIVES: The objective of this study is to see the clinical profile of invasive pneumococcal disease, antibiotics sensitivity pattern and prevalent serotypes in children admitted at Patan Hospital. METHODS: This is a retrospective analytical study conducted in the department of Paediatrics, Patan hospital. The lab data of those children who grew pneumococci in their blood, cerebrospinal fluid or body fluids over a period of 3 years (January 2007 to Dec 2009) were collected and the case files were then studied. RESULTS: Out of 42 cases of invasive pneumococcal diseases studied admitted diagnoses included pneumonia, febrile seizure, bacteremia or septicemia, meningitis, acute gastroenteritis and glomerulonephritis. Twenty seven of them were children under five. The male to female ratio was 1.7:1. On investigation 64%, 52% and 5% of the patients had leucocytosis, anaemia, and leucopenia respectively. Twenty six of them had radiological changes suggestive of pneumonia. Streptococcus pneumoniae grew in 38 blood samples, 5 cerebrospinal fluid and 3 pleural fluids. Almost all of these isolates were sensitive to penicillin, cefotaxime, amoxycillin, choloramphenicol, erythromycin and ofloxacin and resistant to cotrimoxazole and gentamicin. Pneumococcal serotypes found in our study were 1, 14, 5, 23B, 6B, 8, 9A, 9V, 10A, 15 and 23F (11 serotypes). CONCLUSIONS: Penicillin is still the most effective antibiotic for streptococcal infection in our study. Of the pneumococcal serotypes identified; 36% were covered by the 7-valent pneumococcal conjugate vaccine, 54% each by PCV-10 and PCV-13, and 72% by the e 23 valent vaccines.

Legionnaires' disease caused by Legionella longbeachae and Legionella pneumophila: comparison of clinical features, host-related risk factors, and outcomes.

Legionnaires' disease remains an important cause of mortality and morbidity worldwide. Disease caused by Legionella pneumophila has been extensively studied, and its clinical characteristics have been well described. There is, however, little information on disease caused by Legionella longbeachae, despite its importance in some countries. We undertook a retrospective review of culture-positive cases of Legionnaires' disease in the Canterbury region of New Zealand over 10 years, in order to compare the clinical features and outcomes of Legionnaires' disease caused by these two species.

Population-based epidemiology of Staphylococcus aureus bloodstream infection in Canterbury, New Zealand.

BACKGROUND: Few contemporary reports describe population-based incidence of Staphylcoccus aureus bloodstream infection (SABSI). AIM: To describe longitudinal incidence of SABSI in a region of New Zealand with low MRSA prevalence. METHODS: Blood cultures growing S. aureus were identified from hospital laboratories between 1 July 1998 and 30 June 2006. Record linkage was used to combine information from local and national databases into a single patient event record. Information from the New Zealand census was used to determine regional incidence of disease. An address-based measure of deprivation was used to analyse the relationship between incidence and socioeconomic status. Morbidity data were not collected. RESULTS: 779 patients with SABSI were identified (482/779 (62%) male, 297/779 (38%) female). The crude incidence of S. aureus bacteraemia varied between 18.5-27.3/100 000 per annum. Three of 779 isolates (0.4%) were MRSA. Two hundred and seventy-seven of 776 (36%) patients with complete records had hospital-acquired SABSI. One hundred and forty-one of 778 patients (18%) died within 30 days and 235/778 (30%) died within a year. Proportional hazards survival models significantly associated age, male sex and more than 14 days of hospitalization in the year prior to index culture with adverse outcome. Higher socioeconomic status was associated with lower rates of SABSI (adjusted rate ratio 0.74, 95% confidence interval: 0.56-0.98, P= 0.007 after adjustment for age and sex, and comparing the highest and lowest deprivation quintiles). CONCLUSION: Population factors significantly influence SABSI incidence and survival. Further research is required to determine whether these have the potential to invalidate inter-hospital comparison of SABSI incidence as a measure of health-care quality.

Concomitant Staphylococcus aureus bacteriuria is associated with poor clinical outcome in adults with S. aureus bacteraemia.

A retrospective cohort study was undertaken to determine the prognostic significance of Staphylococcus aureus bacteriuria in patients presenting to our hospital with S. aureus bacteraemia between January 2000 and December 2003. A total of 378 patients had at least one positive blood culture for S. aureus, of whom 221 had urine cultured within 24h of presentation. For this group, 206 case records could be retrieved for review. Of these patients, all had meticillin-susceptible S. aureus bacteraemia and 35 (17%) had S. aureus cultured in urine. Logistic regression analysis was used to control for age, genitourinary tract status and comorbidity. Concomitant S. aureus bacteriuria persisted as a significant risk factor for ICU admission [risk ratio (RR): 2.5; 95% confidence interval (CI): 1.06-4.36; P=0.04] and in-hospital mortality (RR: 2.18; 95% CI: 1.05-3.57; P=0.04). Other findings were that cerebrovascular disease in males and increasing age in both sexes were associated with in-hospital and one-year mortality. Prospective studies are warranted exploring the link between S. aureus bacteriuria and clinical outcome in patients with S. aureus bacteraemia.

Incidence and characteristics of viral community-acquired pneumonia in adults.

BACKGROUND: In adults, viral causes of community-acquired pneumonia (CAP) are poorly characterised. The aims of this study were to characterise the viral aetiology of CAP in adults by using an extensive array of viral diagnostic tests and to compare the characteristics of viral pneumonia with those of pneumococcal pneumonia. METHODS: Adults admitted to Christchurch Hospital over a 1-year period with CAP were included in the study. Microbiological testing methods included blood and sputum cultures, urinary antigen testing for Streptococcus pneumoniae and Legionella pneumophila, antibody detection in paired sera and detection of respiratory viruses in nasopharyngeal swabs by immunofluorescence, culture and PCR. RESULTS: Of 304 patients with CAP, a viral diagnosis was made in 88 (29%), with rhinoviruses and influenza A being the most common. Two or more pathogens were detected in 49 (16%) patients, 45 of whom had mixed viral and bacterial infections. There were no reliable clinical predictors of viral pneumonia, although several variables were independently associated with some aetiologies. The presence of myalgia was associated with pneumonia caused by any respiratory virus (OR 3.62, 95% CI 1.29 to 10.12) and influenza pneumonia (OR 190.72, 95% CI 3.68 to 9891.91). Mixed rhinovirus/pneumococcal infection was associated with severe disease. CONCLUSIONS: Virus-associated CAP is common in adults. Polymicrobial infections involving bacterial and viral pathogens are frequent and may be associated with severe pneumonia.

Leptotrichia endocarditis: report of two cases from the International Collaboration on Endocarditis (ICE) database and review of previous cases.

Leptotrichia species typically colonize the oral cavity and genitourinary tract. We report the first two cases of endocarditis secondary to L. goodfellowii sp. nov. Both cases were identified using 16S rRNA gene sequencing. Review of the English literature revealed only two other cases of Leptotrichia sp. endocarditis.

Evaluation of the Mycoplasma Duo kit for the detection of Mycoplasma hominis and Ureaplasma urealyticum from urogenital and placental specimens.

This study compares the Mycoplasma Duo kit for the detection of genital mycoplasmas with conventional culture using A7 differential agar for the detection of Mycoplasma hominis and Ureaplasma urealyticum in clinical samples. Detection of the mycoplasmas is based on the specific metabolic properties of each organism to hydrolyse either arginine or urea. The Mycoplasma Duo test showed a significantly higher detection rate than did culture, although many of the culture-negative results may have been due to the presence of bacterial overgrowth.

Childhood diarrhoea in a district in northeast Thailand: incidence and treatment choices.

Diarrhoeal disease is a major public health problem in Thailand. We collected information on childhood diarrhoea from a district in northeast Thailand, using various approaches which focus on both consumers and providers. The overall incidence of diarrhoea in the study area was 2.1 episodes per child per 12 months, with children under two years of age having a higher rate at 3.0 episodes per child per 12 months. Many episodes were not recognized as diarrhoeal episodes by caregivers, and treatment was sought in just over half of all episodes. Although children received an average of 2.4 items of medicine per episode, there was relatively low use of oral rehydration solutions. This study highlights the importance of assessing local beliefs when collecting data on diarrhoeal diseases in children, and the importance of continuing efforts to improve public health education on the management of diarrhoeal diseases.

The rapid evaluation of bacterial growth in blood cultures by selected ion flow tube-mass spectrometry (SIFT-MS) and comparison with the BacT/ALERT automated blood culture system.

We compared the performance of the BacT/ALERT automated blood culture system with real-time, quantitative volatile organic compound (VOC) detection by selected ion flow tube-mass spectrometry (SIFT-MS). Blood samples from healthy donors were artificially infected with 5 or 100 CFU of organisms commonly causing bacteremia. Positive results by SIFT-MS analysis of headspace gases were recorded for 53/60 (88.3%) bottles at 8h, and 58/60 (96.6%) bottles at 24 h. We conclude that SIFT-MS is a sensitive method for the detection of microbial VOCs. Furthermore, profiles of the VOCs detected may allow simultaneous identification of infecting organisms.

Human metapneumovirus in children with bronchiolitis or pneumonia in New Zealand.

OBJECTIVES: To confirm the presence of human metapneumovirus (hMPV) in New Zealand and establish its prevalence in selected paediatric patient groups. METHODS: Nasopharyngeal swabs were collected in two separate paediatric studies enrolling children clinically diagnosed with either bronchiolitis or pneumonia and tested for hMPV by polymerase chain reaction. RESULTS: Nucleic acid detection tests demonstrated 5.3% of paediatric bronchiolitis cases were positive for hMPV RNA and 2.7% of children admitted with pneumonia tested positive for hMPV RNA. CONCLUSIONS: The presence of hMPV in New Zealand has been confirmed in two selected paediatric patient groups, namely children diagnosed with bronchiolitis and pneumonia. These results indicate that hMPV is associated with a minority of cases of bronchiolitis or pneumonia in this patient group.

Risk factors for infective endocarditis in patients with enterococcal bacteremia: a case-control study.

BACKGROUND: Based on previous studies, enterococcal infective endocarditis (IE) is considered a unimicrobial, community-acquired disease of older Caucasian men. PATIENTS AND METHODS: We evaluated the relationship between enterococcal bacteremia and IE by comparing clinical and demographic characteristics of all cases of enterococcal IE within an 8-year period (n = 41) with controls randomly chosen from patients with enterococcal bacteremia without IE. RESULTS: By univariate and multivariable analyses, the presence of a prosthetic valve (PV) and infection with Enterococcus faecalis were significantly associated with IE, while age, gender, race, polymicrobial infection and community-acquired infection were not. Almost an equal number of women and men had enterococcal IE. Cases of enterococcal IE were commonly nosocomial (39%) and polymicrobial (17%). CONCLUSIONS: Enterococcal endocarditis can no longer be considered exclusively a unimicrobial, community-acquired disease of Caucasian men. Instead, our data suggest that the presence of a PV and infection by E. faecalis are associated with an increased risk for IE.

Rapid identification of Staphylococcus aureus from BacT/ALERT blood culture bottles by direct Gram stain characteristics.

The rapid identification of Staphylococcus aureus from positive blood cultures provides important clinical and therapeutic information. Using criteria based on direct Gram stain characteristics, an experienced microscopist was able to distinguish S aureus from other staphylococci isolated from BacT/ALERT blood culture bottles with an overall sensitivity of 89% and specificity of 98%. Furthermore, this method was readily taught to a clinical microbiologist who had not previously used the method first hand. Laboratories using the BacT/ALERT blood culture system should become familiar with these criteria so that S aureus bacteraemia can be identified rapidly.