Dominant role of nucleotide substitution in the diversification of serotype 3 pneumococci over decades and during a single infection.

Streptococcus pneumoniae of serotype 3 possess a mucoid capsule and cause disease associated with high mortality rates relative to other pneumococci. Phylogenetic analysis of a complete reference genome and 81 draft sequences from clonal complex 180, the predominant serotype 3 clone in much of the world, found most sampled isolates belonged to a clade affected by few diversifying recombinations. However, other isolates indicate significant genetic variation has accumulated over the clonal complex's entire history. Two closely related genomes, one from the blood and another from the cerebrospinal fluid, were obtained from a patient with meningitis. The pair differed in their behaviour in a mouse model of disease and in their susceptibility to antimicrobials, with at least some of these changes attributable to a mutation that up-regulated the patAB efflux pump. This indicates clinically important phenotypic variation can accumulate rapidly through small alterations to the genotype.

A very unusual organism causing stroke-like symptoms.

A 78-year-old man presented to hospital with new onset confusion and fever. The working diagnosis was of delirium due to an infection of unknown source, and empirical i.v. antibiotic treatment was given. Two days later, he deteriorated and developed clinical features in keeping with a total anterior circulation stroke. Brain imaging was unremarkable. Blood cultures grew an organism subsequently identified as Facklamia languida. Following treatment with broad-spectrum antibiotics, his condition improved. A diagnosis of F. languida septicaemia, leading to presumed (unwitnessed) seizure and Todd's paresis was made. The patient went on to make a full recovery and was discharged home. Stroke mimics are common and may be eminently treatable. Around a quarter of patients initially suspected to have a stroke are subsequently found to have an alternative diagnosis.

Bedside leucocyte esterase reagent strips with spectrophotometric analysis to rapidly exclude spontaneous bacterial peritonitis: a pilot study.

BACKGROUND: Spontaneous bacterial peritonitis, a potentially fatal complication of cirrhotic ascites, is diagnosed when the polymorphonuclear leucocyte count in the ascitic fluid is>250/mm. Manual laboratory counting of ascitic polymorphonuclear leucocytes is, however, labour-intensive, costly, results in diagnostic delay and it is not available in all hospitals as part of the 'out-of-hours' service. Thus, a rapid diagnostic screening test for spontaneous bacterial peritonitis would be beneficial in this condition. An exciting new development in the diagnosis of spontaneous bacterial peritonitis is the use of bedside reagent strips; yet, concerns regarding the inherent subjectivity of result reading have prevented the widespread adoption of this technique in clinical practice. OBJECTIVE: To evaluate the combined use of a leucocyte esterase strip together with an objective portable spectrophotometric reading device in the diagnosis of spontaneous bacterial peritonitis when compared with standard manual laboratory polymorphonuclear leucocyte counting. METHODS: Nonselected cirrhotic patients undergoing diagnostic paracentesis had an ascitic sample sent for a conventional polymorphonuclear leucocyte count, Gram stain and culture. In addition, a sample was tested with a bedside Multistix 10SG reagent strip and the result was analysed by the Clinitek Status. The strip test was considered positive if it read anything other than negative (i.e. 'trace', '+1', '+2' or '+3'). RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the reagent strips to diagnose correctly spontaneous bacterial peritonitis when compared with the manual laboratory polymorphonuclear leucocyte count were 100, 91, 50, 100 and 92%, respectively. CONCLUSIONS: Bedside leucocyte esterase strips, spectrophotometrically read, can reliably exclude spontaneous bacterial peritonitis in patients with cirrhotic ascites. In our series, a negative strip result effectively ruled out this important condition, and suggests that the requirement for manual polymorphonuclear leucocyte counting in this setting could be removed.

Heroin-associated anthrax with minimal morbidity.

In 2010, during an outbreak of anthrax affecting people who inject drugs, a heroin user aged 37 years presented with soft tissue infection. He subsequently was found to have anthrax. We describe his management and the difficulty in distinguishing anthrax from non-anthrax lesions. His full recovery, despite an overall mortality of 30% for injectional anthrax, demonstrates that some heroin-related anthrax cases can be managed predominately with oral antibiotics and minimal surgical intervention.

Assessing the impact of a temporary class drug order on ethylphenidate-related infections among people who inject drugs in Lothian, Scotland: an interrupted time-series analysis.

BACKGROUND AND AIMS: In April 2015, the UK government enacted a temporary class drug order (TCDO) on ethylphenidate in response to reported harms associated with its use, in particular an outbreak of infections among people who inject drugs (PWID) in Lothian, Scotland. This study assesses the effect that the TCDO had on reducing the most common infections identified during the outbreak: Streptococcus pyogenes and Staphylococcus aureus. DESIGN: The outbreak was split into a pre-intervention period (35 weeks) and a post-intervention period (26 weeks) based around the date of the TCDO. Segmented negative binomial regression models were used to compare trends in weekly counts of infections between the pre- and post-intervention periods. SETTING AND PARTICIPANTS: PWID in the Lothian region of Scotland. MEASUREMENTS: Cases of S. pyogenes and S. aureus infections reported within the National Health Service, Lothian. FINDINGS: There were 251 S. pyogenes and/or S. aureus infections recorded among 211 PWID between February 2014 and December 2015: 171 infections in the pre-intervention period and 51 in the post-intervention period. Significant trend changes in weekly S. pyogenes and/or S. aureus infections following the TCDO were found [relative risk (RR) = 0.88, 95% confidence interval (CI) = 0.82-0.94]. PWID who self-reported using novel psychoactive substances (NPS) were at higher risk of acquiring these infections (RR = 1.81, 95% CI = 1.12-2.93), particularly when comparing the risk of infection with NPS use for a specific strain, S. pyogenes emm76.0, against the risk of infection with NPS use for S. pyogenes (emm types other than emm76.0) (RR = 3.49, 95% CI = 1.32-9.21). CONCLUSIONS: The UK government's 2015 temporary class drug order on ethylphenidate was effective in reducing infections among people who inject drugs during an outbreak situation in Lothian, Scotland.

The effect of a quality improvement programme reducing blood culture contamination on the detection of bloodstream infection in an emergency department.

BACKGROUND: Contaminated blood cultures (BC) generate avoidable costs and prolong hospital stays. To measure our hospital's performance against the recommended standard of <3% BC contamination, we performed a prospective study. METHODS: We prospectively determined the frequency of contaminated and genuinely positive BC hospital-wide over seven months. RESULTS: Overall, 73 of 1,829 blood cultures reviewed were contaminated (4.0%). However, distribution of contamination was not uniform. Finding a consistently higher incidence of contamination (11.7%) in our emergency department (ED) than elsewhere in the hospital (2.5%), we adopted a collaborative quality improvement strategy targeted to the ED. A combination of education, modified BC packs and regular feedback of BC results was associated with a significant reduction in contamination (7.4%, p=0.01) over the next six months. Our data suggests that contaminated BC were more likely to have been taken during regular day time hours (odds ratio (OR) 2.7, p=0.012), rather than overnight and were not associated with influxes of new junior medical staff. We found no evidence that the incidence of true bloodstream infection (12.8%) diagnosed by our ED was adversely affected by our intervention (10.7%, p=0.35). CONCLUSIONS: Using a simple and inexpensive collaborative intervention we reduced BC contamination without adversely affecting the detection of genuine BSI.

The spectrum of HIV-related disease in rural Central Thailand.

To determine the spectrum of HIV-related illnesses presenting to a rural primary and secondary healthcare facility in Central Thailand, a cross-sectional study was conducted. Routinely collected data were extracted from outpatient medical notes for all adult HIV-infected new attenders of the Manorom Christian Hospital Infectious Disease Clinic. Data concerning inpatient admissions of HIV-infected individuals were collected from ward admission books and discharge summaries. Complete data were available for 229 outpatients, 70% of whom were men. The median age at presentation was 31 years for men and 30 years for women. The majority of the outpatients were married (69%) and infected heterosexually (91%). The commonest conditions requiring admission were cryptococcal meningitis (15%), bacterial pneumonia (12%), extrapulmonary tuberculosis (12%), Pneumocystis carinii pneumonia (7%), cerebral toxoplasmosis (4%) and pulmonary tuberculosis (3%). Of the patients presenting for the first time, 32% had AIDS-defining illnesses. Presentations with some conditions, such as tuberculosis and septicemia, were fewer than expected. The common opportunistic infections among HIV-infected adults in this rural region are treatable and preventable. Most patients present with advanced disease and earlier diagnosis, through improved access to voluntary counseling and testing, would enable them to receive appropriate preventive therapies and antiretrovirals as they becomes available. The high prevalence of cryptococcal disease suggests that prophylactic anti-fungal therapy may be of value in this area. Septicemia and tuberculosis may be under-diagnosed, highlighting the need for improved diagnostic laboratory facilities or treatment based upon validated clinical algorithms. Community care and palliative care services for HIV-infected individuals will increasingly be required in this region.

Screening haematology patients for carbapenem-resistant Klebsiella pneumoniae.

Following a cluster of haematology patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) septicaemia, we initiated screening for rectal carriage of CRKP and multidrug-resistant K. pneumoniae (MDRKP) in this patient group. Haematology inpatients submit a rectal swab once weekly. When plated onto chromogenic Brilliance™ UTI Agar (Oxoid), and incubated overnight with a 10 µg ertapenem disc (Oxoid), K. pneumoniae is identified and semi-automated antibiotic susceptibility testing is performed using the Vitek 2 analyser (Biomerieux). When no zone of inhibition occurs, immediate intervention through patient isolation and enhanced environmental cleaning can be instigated to control further spread while empirical antibiotic prescribing is adapted to take account of identified resistances. Over 2 years, six patients with CRKP and 20 patients with MDRKP were identified. These isolates were resistant to first-line empirical treatment choices for neutropenic sepsis and presented a clinical risk of treatment failure for sepsis post cytotoxic chemotherapy. We describe how this rectal screening methodology was developed and how the results influenced appropriate antibiotic prescribing, patient placement in single rooms and the cleaning of the ward environment to prevent person-to-person transmission of MDRKP and CRKP.

Trends in serotypes and sequence types among cases of invasive pneumococcal disease in Scotland, 1999-2010.

INTRODUCTION: The 7-valent pneumococcal conjugate vaccine (Prevenar(®), Wyeth; PCV7) was introduced to the UK paediatric immunisation schedule in 2006. This study investigates trends in serotypes and multi locus sequence types (STs) among cases of invasive pneumococcal disease (IPD) in Scotland prior to, and following, the introduction of PCV7. METHODS: Scottish Invasive Pneumococcal Disease Enhanced Surveillance has records of all cases of IPD in Scotland since 1999. Cases diagnosed from blood or cerebrospinal fluid isolates until 2010 were analysed. Logistic and poisson regression modelling was used to assess trends prior to and following the introduction of PCV7. RESULTS: Prior to PCV7 use, on average 650 cases of IPD were reported each year; 12% occurred in those aged <5 years and 35% affected those aged over 65 years. Serotypes in PCV7 represented 47% of cases (68% in <5 year olds). The serotype and ST distribution was relatively stable with only serotype 1 and associated ST 306 showing an increasing trend. PCV7 introduction was associated with a 69% (95% CI: 50%, 80%) reduction in the incidence of IPD among those aged <5 years, a 57% (95% CI: 47%, 66%) reduction among those aged 5-64 years but no significant change among those aged 65 years and over where increases in non-PCV7 serotypes were observed. Serotypes which became more prevalent post-PCV7 are those which were associated with STs related to the PCV7 serotypes. CONCLUSIONS: Routine serotyping and sequence typing in Scotland allowed the assessment of the relationship between the capsule and the clones in the post vaccination era. Changes in the distribution of serotypes post PCV7 introduction appear to be driven by associations between serotypes and STs prior to PCV7 introduction. This has implications for the possible effects of the introduction of higher valency vaccines and could aid in predicting replacement serotypes in IPD.

Investigating the role of pneumococcal neuraminidase A activity in isolates from pneumococcal haemolytic uraemic syndrome.

Streptococcus pneumoniae diseases are a rare but increasingly recognized trigger of atypical haemolytic uraemic syndrome (HUS) in young children and associated with a higher mortality rate than diarrhoea-associated HUS. This study aimed to determine the importance of neuraminidase A (NanA) and genomic diversity in the pathogenesis of pneumococcal HUS (pHUS). We investigated the nanA gene sequence, gene expression, neuraminidase activity and comparative genomic hybridization of invasive pneumococcal disease (IPD) isolates from patients with pHUS and control strains matched by serotype and sequence type (ST), isolated from patients with IPD but not pHUS. The nanA sequence of 33 isolates was determined and mutations at 142 aa positions were identified. High levels of diversity were observed within the NanA protein, with mosaic blocks, insertions and repeat regions present. When comparing nanA allelic diversity with ST and disease profile in the isolates tested, nanA alleles clustered mostly by ST. No particular nanA allele was associated with pHUS. There was no significant difference in overall neuraminidase activity between pHUS isolates and controls when induced/uninduced with N-acetylneuraminic acid. Comparative genomic hybridization showed little difference in genetic content between the pHUS isolates and the controls. Results of gene expression studies identified 12 genes differentially regulated in all pHUS isolates compared with the control. Although neuraminidase enzyme activity may be important in pHUS progression and contribute to pathogenesis, the lack of a distinction between pHUS isolates and controls suggests that host factors, such as acquired abnormalities of the alternative complement cascade in young children, may play a more significant role in the outcome of pHUS.

Treated follicular lymphoma, recurrent invasive pneumococcal disease, nonresponsiveness to vaccination, and a unique pneumococcus.

A nonneutropenic patient with treated low-grade non-Hodgkin's (Follicular) lymphoma and secondary hypogammaglobulinemia recovered from pneumococcal pneumonia and septicemia (serotype 7F; ST191) subsequent to influenza A H1N1 (2009). Both infections were potentially vaccine preventable. The patient then developed pneumococcal meningitis due to a serotype 35F pneumococcus with a unique Multilocus Sequence Type (ST7004) which was not vaccine preventable. Patient management was influenced by host predisposition to pneumococcal infection, antibiotic intolerance, and poor response to polysaccharide pneumococcal vaccine. Indirect immunofluorescence with anti-human immunoglobulin confirmed a poor or intermediate response to Pneumovax II. Prophylactic erythromycin was initiated, and immunoglobulin transfusions were also commenced as a preventive strategy. ST7004 is a single locus variant of ST1635 which has been associated with the serotype 35F capsule in England. The spi gene in ST7004, which differentiates it from ST1635, is the same as the spi gene present in ST191 which could have arisen from the first disease episode suggesting that horizontal gene transfer may have occurred between different populations of pneumococci present within the patient in an attempt to evade vaccination selection pressure.

Death or survival from invasive pneumococcal disease in Scotland: associations with serogroups and multilocus sequence types.

We describe associations between death from invasive pneumococcal disease (IPD) and particular serogroups and sequence types (STs) determined by multilocus sequence typing (MLST) using data from Scotland. All IPD episodes where blood or cerebrospinal fluid (CSF) culture isolates were referred to the Scottish Haemophilus, Legionella, Meningococcal and Pneumococcal Reference Laboratory (SHLMPRL) from January 1992 to February 2007 were matched to death certification records by the General Register Office for Scotland. This represented 5959 patients. The median number of IPD cases in Scotland each year was 292. Deaths, from any cause, within 30 days of pneumococcal culture from blood or CSF were considered to have IPD as a contributing factor. Eight hundred and thirty-three patients died within 30 days of culture of Streptococcus pneumoniae from blood or CSF [13.95 %; 95 % confidence interval (13.10, 14.80)]. The highest death rates were in patients over the age of 75. Serotyping data exist for all years but MLST data were only available from 2001 onward. The risk ratio of dying from infection due to particular serogroups or STs compared to dying from IPD due to all other serogroups or STs was calculated. Fisher's exact test with Bonferroni adjustment for multiple testing was used. Age adjustment was accomplished using the Cochran-Mantel-Haenszel test and 95 % confidence intervals were reported. Serogroups 3, 11 and 16 have increased probability of causing fatal IPD in Scotland while serogroup 1 IPD has a reduced probability of causing death. None of the 20 most common STs were significantly associated with death within 30 days of pneumococcal culture, after age adjustment. We conclude that there is a stronger association between a fatal outcome and pneumococcal capsular serogroup than there is between a fatal outcome and ST.

Simultaneous nasopharyngeal carriage of two pneumococcal multilocus sequence types with a serotype 3 phenotype.

Knowledge of the epidemiology of pneumococcal disease in Bolivia is sparse, and Multilocus Sequence Typing (MLST) of isolates has not been previously possible. Beni state has until recently been a geographically isolated region of the Bolivian Amazon basin and is a region of significant poverty. During June and July 2007, we performed a pneumococcal carriage study recruiting over 600 schoolchildren in two towns in the Beni state. Here, we describe the unique identification of simultaneous nasopharyngeal carriage of two pneumococcal multilocus sequence types with a serotype 3 phenotype within a single subject.

Antibiotic resistance in invasive Streptococcus pneumoniae isolates identified in Scotland between 1999 and 2007.

Data from 4727 invasive isolates of Streptococcus pneumoniae submitted to the Scottish Haemophilus, Legionella, Meningococcus and Pneumococcus Reference Laboratory between 1999 and 2007 were analysed to establish susceptibility profiles to penicillin, erythromycin and cefotaxime. Pneumococcal resistance to penicillin over the study period remained low, with only 0.2 % (n=7/4727) of isolates falling into this category (MIC ≥2 mg l(-1)). These isolates have been sporadic, and have mainly represented serogroup 14 (ST9) and 9 (ST156). In comparison, the 'intermediate sensitivity' group (MIC 0.12-1 mg l(-1)) ranged between 2 and 6 % per year, the majority from serogroup 9 (ST156). Over the study period, we found that 12 % (n=585/4727) of isolates were erythromycin-resistant (MIC >0.5 mg l(-1)), with the majority (n=467; 80 %) of these isolates identified as serogroup 14 (ST9). Cephalosporin resistance (cefotaxime MIC >1 mg l(-1)) was found in only 0.06 % (n=2/3135) of isolates. Internationally recognized clones (Pneumococcal Molecular Epidemiology Network) accounted for 35 % (n=28/81) of the penicillin non-susceptible isolates and 75 % (n=248/330) of the macrolide-resistant isolates, with ST9 and ST306 predominating. Between 1999 and 2007 we found that 11.6 % (n=18/155) of the penicillin non-susceptible isolates and 4.8 % (n=28/585) of the macrolide-resistant isolates were from serogroups not covered by the 7-valent conjugate pneumococcal vaccine in use in the UK since 2006. Susceptibility to first-line antimicrobial agents for invasive pneumococcal disease in Scotland remained high over the period 1999-2007.