Assessment of nasopharyngeal Streptococcus pneumoniae colonization does not permit discrimination between Canadian children with viral and bacterial respiratory infection: a matched-cohort cross-sectional study.

BACKGROUND: Readily-available diagnostics do not reliably discriminate between viral and bacterial pediatric uncomplicated pneumonia, both of which are common. Some have suggested that assessment of pneumococcal carriage could be used to identify those children with bacterial pneumonia. The objective of this study was to determine if nasopharyngeal pneumococcal colonization patterns differed between children with definite viral disease, definite bacterial disease, and respiratory disease of indeterminate etiology. METHODS: Three groups of subjects were recruited: children with critical respiratory illness, previously healthy children with respiratory illness admitted to the ward, and previously healthy children diagnosed in the emergency department with non-severe pneumonia. Subjects were categorized as follows: a) viral infection syndrome (eg. bronchiolitis), b) bacterial infection syndrome (ie. pneumonia complicated by effusion/empyema), or c) 'indeterminate' pneumonia. Subjects' nasopharyngeal swabs underwent quantitative PCR testing for S. pneumoniae. Associations between categorical variables were determined with Fisher's exact, chi-square, or logistic regression, as appropriate. Associations between quantitative genomic load and categorical variables was determined by linear regression. RESULTS: There were 206 children in Group 1, 122 children in Group 2, and 179 children in Group 3. Only a minority (227/507, 45%) had detectable pneumococcal carriage; in those subjects, there was no association of quantitative genomic load with age, recruitment group, or disease category. In multivariate logistic regression, pneumococcal colonization > 3 log copies/mL was associated with younger age and recruitment group, but not with disease category. CONCLUSIONS: The nasopharyngeal S. pneumoniae colonization patterns of subjects with definite viral infection were very similar to colonization patterns of those with definite bacterial infection or indeterminate pneumonia. Assessment and quantification of nasopharyngeal pneumococcal colonization does not therefore appear useful to discriminate between acute viral and bacterial respiratory disease; consequently, this diagnostic testing is unlikely to reliably determine which children with indeterminate pneumonia have a bacterial etiology and/or require antibiotic treatment.

Evaluation of the FecalSwab for Stool Specimen Storage and Molecular Detection of Enteropathogens on the BD Max System.

The FecalSwab system (Copan Italia, Brescia, Italy) is a convenient alternative to bulk stool for the diagnosis of enteric pathogens. Although the U.S. Food and Drug Administration (FDA) approved for transport and culture of enteric bacterial pathogens, the FecalSwab has not been well assessed for its suitability with molecular platforms. In this study, we evaluated the FecalSwab as a specimen type for the BD Max system using the viral and bacterial enteric panels (BD Diagnostics, Baltimore, MD, USA). A total of 186 unpreserved stool specimens were collected and used to prepare matched bulk stool and FecalSwab samples. Performance was equivalent (P > 0.48) to bulk stool for all targets when 50 µl of FecalSwab specimen was loaded onto the BD Max assays. As stool specimens are often collected off-site from the clinical microbiology laboratory and require transport, we assessed the stability of stool specimens stored for up to 14 days at 4°C, 22°C, or 35°C to account for varying transportation conditions. Molecular detection for the majority of viral targets (excluding astrovirus) was unaffected (change in cycle threshold [ΔCT ] ≤ 1) by sample storage temperature over the 2-week period; however, detection of enteric bacteria was variable if specimens were not refrigerated (22°C or 35°C). By demonstrating equivalent performance to matched bulk stool and maintaining molecular detection sensitivity when stored at 4°C, we suggest that the FecalSwab is a suitable specimen type for enteropathogen diagnostics on the BD Max system.

The prevalence and clinical characteristics of pertussis-associated pneumonia among infants in Botswana.

BACKGROUND: There are scant data on the prevalence and clinical course of pertussis disease among infants with pneumonia in low- and middle-income countries. While pertussis vaccination coverage is high (≥90%) among infants in Botswana, human immunodeficiency virus (HIV) infection affects nearly one-third of pregnancies. We aimed to evaluate the prevalence and clinical course of pertussis disease in a cohort of HIV-unexposed uninfected (HUU), HIV-exposed uninfected (HEU), and HIV-infected infants with pneumonia in Botswana. METHODS: We recruited children 1-23 months of age with clinical pneumonia at a tertiary care hospital in Gaborone, Botswana between April 2012 and June 2016. We obtained nasopharyngeal swab specimens at enrollment and tested these samples using a previously validated in-house real-time PCR assay that detects a unique sequence of the porin gene of Bordetella pertussis. RESULTS: B. pertussis was identified in 1/248 (0.4%) HUU, 3/110 (2.7%) HEU, and 0/33 (0.0%) HIV-infected children. All pertussis-associated pneumonia cases occurred in infants 1-5 months of age (prevalence, 1.0% [1/103] in HUU and 4.8% [3/62] in HEU infants). No HEU infants with pertussis-associated pneumonia were taking cotrimoxazole prophylaxis at the time of hospital presentation. One HUU infant with pertussis-associated pneumonia required intensive care unit admission for mechanical ventilation, but there were no deaths. CONCLUSIONS: The prevalence of pertussis was low among infants and young children with pneumonia in Botswana. Although vaccination against pertussis in pregnancy is designed to prevent classical pertussis disease, reduction of pertussis-associated pneumonia might be an important additional benefit.

Ease, Comfort, and Performance of the HerSwab Vaginal Self-Sampling Device for the Detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

BACKGROUND: Many sexually transmitted diseases are asymptomatic in the lower genital tract and can cause upper tract complications if left untreated. Self-collected vaginal (SCV) swabs enable the accurate detection of many sexually transmitted infections and give women the option of collecting their own samples while providing them with privacy and convenience. METHODS: We compared SCV samples collected and transported dry using the HerSwab device to physician-collected vaginal (PCV) Aptima swabs for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), and measured patients' ease and comfort with self-collection. A total of 189 women aged 16 to 41 years were consented into the study and answered a standardized anonymized questionnaire regarding self-collection with the HerSwab device. RESULTS: Women reported self-collection with HerSwab to be easy (97.1%) and comfortable (88.3%). They preferred self-collection over physician collection (80.9%) and would consider using HerSwab for self-collection at home (79.7%). Samples of SCV and PCV showed an overall agreement of 94.7% (κ = 0.64) for CT and of 98.4% (κ = 0.56) for NG, and HerSwab collection detected 7 more positive patients than PCV collection. The overall prevalence of infection was 10.6% for CT and 2.6% for NG. CONCLUSION: HerSwab SCV samples are suitable for the diagnosis of CT and NG.

Throat and nasal swabs for molecular detection of respiratory viruses in acute pharyngitis.

BACKGROUND: Detection of specific respiratory viruses is important for surveillance programs, where nasopharyngeal or nasal swabs have traditionally been used. Our objective was to determine whether sampling with a throat swab provides incremental benefit-when used in conjunction with a nasal swab-to detect respiratory viruses among patients with acute pharyngitis in the outpatient setting. FINDINGS: Among 83 university students with acute pharyngitis, we detected respiratory viruses with molecular assays on two samples collected per student: with a flocked nasal mid-turbinate swab and a rayon throat swab. Forty-eight (58 %) patients had virus-positive samples, with 49 virus positives detected by either swab (one patient had a dual viral co-infection). The most common viruses were rhinovirus, coronavirus, and influenza A virus. Specifically, 29 virus positives were detected by both swabs, 14 exclusively by the nasal swab, and six exclusively by the throat swab. The additional six virus positives detected by the throat swab corresponded to an absolute increase in viral detection of 7.1 % (95 % CI: 1.2-12.9 %); the specific viruses detected were four rhinoviruses and two coronaviruses. CONCLUSIONS: The flocked nasal swab samples respiratory viruses well, even among patients whose primary complaint is a sore throat. The rayon throat swab has modest incremental value over and above using the flocked nasal mid-turbinate swab alone, which suggests that while throat swabs alone would not be adequate for respiratory viral surveillance, they may have value as a supplementary test.

Clinical severity of pediatric respiratory illness with enterovirus D68 compared with rhinovirus or other enterovirus genotypes.

BACKGROUND: Enterovirus D68 (EV-D68) resulted in a reported increase in the number of children needing hospital or critical care admission because of respiratory insufficiency during 2014. It remains unclear, however, whether EV-D68 infections were more severe than rhinovirus or non-EV-D68 enterovirus infections. METHODS: We evaluated consecutive children presenting to a pediatric hospital between Aug. 1 and Oct. 31, 2014, with positive nasopharyngeal swabs for rhinovirus or enterovirus that were sent automatically for EV-D68 testing. We compared characteristics and outcomes of patients with EV-D68 with those with rhinovirus or non-EV-D68 enterovirus in a matched cohort study. RESULTS: A total of 93/297 (31.3%) of rhinovirus or enterovirus samples tested positive for EV-D68, and it was possible to compare 87 matched pairs. Children with EV-D68 infection were more likely to have difficulty breathing (odds ratio [OR] 3.00, 95% confidence interval [CI] 1.47-6.14). There was no significant difference in admission to the critical care unit or death among children with EV-D68 infection compared with those with other rhinovirus or enterovirus infections (adjusted OR 1.47, 95% CI 0.61-3.52). Children with EV-D68 infection were more often admitted to hospital, but not significantly so (adjusted OR 2.29, 95% CI 0.96-5.46). INTERPRETATION: Enterovirus D68 seems to be a more virulent pulmonary pathogen than rhinovirus or non-EV-D68 enterovirus, but we did not find a significant difference in death or need for critical care.

Evaluation of anatomically designed flocked rectal swabs for molecular detection of enteric pathogens in children admitted to hospital with severe gastroenteritis in Botswana.

Two-hundred eighty matched bulk stool and anatomically designed flocked rectal swab samples were collected from children admitted to the hospital with acute diarrhea in Botswana. Their parents were asked about the acceptability of the swab collection method compared with bulk stool sampling. All samples underwent identical testing with a validated 15-target (9 bacterial, 3 viral, and 3 parasite) commercial multiplex PCR assay. The flocked swabs had a 12% higher yield for bacterial pathogen targets (241 versus 212; P = 0.003) compared with that of stool samples, as well as similar yields for viral targets (110 versus 113; P = 0.701) and parasite targets (59 versus 65; P = 0.345). One hundred sixty-four of the flocked swab-stool pairs were also tested with separate laboratory-developed bacterial and viral multiplex assays, and the flocked rectal swabs had a performance that was similar to that seen with commercial assay testing. Almost all parents/guardians found the swabs acceptable. Flocked rectal swabs significantly facilitate the molecular diagnosis of diarrheal disease in children.

Vitamin D3 and gargling for the prevention of upper respiratory tract infections: a randomized controlled trial.

BACKGROUND: We undertook a 2X2 factorial, randomized controlled trial (RCT) to assess whether vitamin D3 supplementation (10,000 international units per week) versus placebo and gargling versus no gargling could prevent viral, clinical upper respiratory tract infection (URTI) in university students. METHODS: We randomized 600 students into 4 treatment arms: 1) vitamin D3 and gargling, 2) placebo and gargling, 3) vitamin D3 and no gargling, and 4) placebo and no gargling. Students completed weekly electronic surveys and submitted self-collected mid-turbinate nasal flocked swabs during September and October in 2010 or 2011. Symptomatic students also completed an electronic symptom diary. The primary and secondary outcomes were the occurrence of symptomatic clinical URTI and laboratory confirmed URTI respectively. RESULTS: Of 600 participants, 471 (78.5%) completed all surveys while 43 (7.2%) completed none; 150 (25.0%) reported clinical URTI. Seventy participants (23.3%) randomized to vitamin D3 reported clinical URTI compared to 80 (26.7%) randomized to placebo (RR:0.79, CI95:0.61-1.03, p = 0.09). Eighty-five participants (28.3%) randomized to gargling reported clinical URTI compared to 65 participants (21.7%) randomized to the no gargling arm (RR:1.3, CI95:0.92-1.57, p = 0.19). Laboratory testing identified 70 infections (46.7 per 100 URTIs). Vitamin D3 treatment was associated with a significantly lower risk for laboratory confirmed URTI (RR: 0.54, CI95:0.34-0.84, p = 0.007) and with a significantly lower mean viral load measured as log10 viral copies/mL (mean difference: -0.89, CI95: -1.7, -0.06, p = 0.04). Fewer students assigned to gargling experienced laboratory confirmed URTI, however this was not statistically significant (RR:0.82, CI95:0.53-1.26, p = 0.36). CONCLUSIONS: These results suggest that vitamin D3 is a promising intervention for the prevention of URTI. Vitamin D3 significantly reduced the risk of laboratory confirmed URTI and may reduce the risk of clinical infections. CLINICAL TRIALS REGISTRATION: NCT01158560.

Prevalence of Haemophilus influenzae in the nasopharynx of children from regions with varying incidence of invasive H. influenzae serotype a disease: Canadian Immunization Research Network (CIRN) study.

Haemophilus influenzae serotype a (Hia) has recently emerged as an important cause of invasive disease in the North American Arctic and Sub-Arctic regions, mainly affecting young Indigenous children. In this study, we addressed the question of whether the prevalence of Hia and all H. influenzae in the nasopharynx differed between paediatric populations from regions with high versus low incidence of invasive Hia disease. Nasopharyngeal specimens from children with acute respiratory tract infections (ARTI) collected for routine diagnostic detection of respiratory viruses were analysed with molecular-genetic methods to identify and serotype H. influenzae. In Nunavut, a region with a high incidence of invasive Hia disease, all H. influenzae and particularly Hia were found in the nasopharynx of 60.6% and 3.0% children. In Southern Ontario (Hamilton region), where Hia invasive disease is rare, the frequencies of all H. influenzae and Hia detection were 38.5% and 0.6%, respectively. In both cohorts, non-typeable H. influenzae was prevalent (57.0% and 37.9%, respectively). Considering that Hia is an important cause of severe invasive disease in Nunavut children, 3% prevalence of Hia among children with ARTI can reflect continuing circulation of the pathogen in the Northern communities that may result in invasive disease outbreaks.

Serotype epidemiology and antibiotic resistance of pneumococcal isolates colonizing infants in Botswana (2016-2019).

BACKGROUND: In 2012, Botswana introduced 13-valent pneumococcal conjugate vaccine (PCV-13) to its childhood immunization program in a 3+0 schedule, achieving coverage rates of above 90% by 2014. In other settings, PCV introduction has been followed by an increase in carriage or disease caused by non-vaccine serotypes, including some serotypes with a high prevalence of antibiotic resistance. METHODS: We characterized the serotype epidemiology and antibiotic resistance of pneumococcal isolates cultured from nasopharyngeal samples collected from infants (≤12 months) in southeastern Botswana between 2016 and 2019. Capsular serotyping was performed using the Quellung reaction. E-tests were used to determine minimum inhibitory concentrations for common antibiotics. RESULTS: We cultured 264 pneumococcal isolates from samples collected from 150 infants. At the time of sample collection, 81% of infants had received at least one dose of PCV-13 and 53% had completed the three-dose series. PCV-13 serotypes accounted for 27% of isolates, with the most prevalent vaccine serotypes being 19F (n = 20, 8%), 19A (n = 16, 6%), and 6A (n = 10, 4%). The most frequently identified non-vaccine serotypes were 23B (n = 29, 11%), 21 (n = 12, 5%), and 16F (n = 11, 4%). Only three (1%) pneumococcal isolates were resistant to amoxicillin; however, we observed an increasing prevalence of penicillin resistance using the meningitis breakpoint (2016: 41%, 2019: 71%; Cochran-Armitage test for trend, p = 0.0003) and non-susceptibility to trimethoprim-sulfamethoxazole (2016: 55%, 2019: 79%; p = 0.04). Three (1%) isolates were multi-drug resistant. CONCLUSIONS: PCV-13 serotypes accounted for a substantial proportion of isolates colonizing infants in Botswana during a four-year period starting four years after vaccine introduction. A low prevalence of amoxicillin resistance supports its continued use as the first-line agent for non-meningeal pneumococcal infections. The observed increase in penicillin resistance at the meningitis breakpoint and the low prevalence of resistance to ceftriaxone supports use of third-generation cephalosporins for empirical treatment of suspected bacterial meningitis.

Likelihood of hospitalization for a chronic respiratory condition following pediatric infection with enterovirus and rhinovirus strains.

Background: Rhino-enteroviruses, particularly enterovirus strain D68 (EV-D68), have been associated with severe respiratory distress in children. The goal of this study was to compare the long-term outcomes of children with EV-D68 infection to that of children with other enterovirus / rhinovirus. Methods: Nasopharyngeal swabs from 174 children presenting with respiratory distress were tested by PCR for respiratory viruses. The primary outcome was diagnosis of a chronic respiratory condition within the follow-up period. Admission to intensive care, and length of stay were recorded. Odds ratios were determined using multinomial logistic regression. Results: During 5 years of follow-up, the crude odds of diagnosis with a chronic respiratory condition were significantly more likely in EV-D68 cases (OR: 1.95, 95% CI: 1.02, 3.82), but failed to remain significant after adjusting for a past history of asthma. Upon admission for a primary concern of asthma, length of stay both in hospital and intensive care were significantly longer in EV-D68 cases (OR: 2.10 [95% CI: 1.56, 2.82, p < 0.001]) and (OR: 5.18 [95% CI: 1.90, 6.28, p < 0.001]), respectively. After adjustment for a history of asthma, EV-D68 cases had significantly longer length of stay in hospital, admitted for 1.94 days for each day that controls were admitted (95% CI: 1.40, 2.68). In admissions to intensive care, EV-D68 cases spent 2.74 days for each day of admission in controls (95% CI: 1.62, 4.97, p < 0.001). Conclusions: Ours is first study to assess prognostic respiratory outcomes of patients infected with EV-D68 in childhood. Our study finds that EV-D68 cases were significantly more likely be hospitalized for longer than other enterovirus/rhinovirus controls in subsequent admissions for respiratory distress. Need for intensive care was significantly longer in EV-D68 infections. Our next steps will be validation in a larger sample size.

Evaluation and clinical validation of an alcohol-based transport medium for preservation and inactivation of respiratory viruses.

The clinical and public health importance of influenza and other respiratory viruses has accelerated the development of highly sensitive molecular diagnostics, but data are limited regarding preanalytical stages of diagnostic testing. We evaluated CyMol, an alcohol-based transport medium, for its ability to maintain specimen integrity for up to 21 days of storage at various temperatures; for its ability to inactivate virus; and for its compatibility with antigen- or nucleic acid-based diagnostics for respiratory viruses in clinical samples. In mock-infected samples, both universal transport medium (UTM-RT) and CyMol maintained equivalent viral quantities for at least 14 days at room temperature or colder, whereas a dry swab collection maintained viral quantities only if refrigerated or frozen. CyMol inactivated influenza virus within 5 min of sample immersion. UTM-RT- and CyMol-collected nasal swab specimens from 73 symptomatic students attending a campus health clinic were positive for a respiratory virus in 56.2% of subjects by multiplex PCR testing, including influenza A and B viruses, rhinovirus/enteroviruses, coronaviruses, respiratory syncytial virus, parainfluenza viruses, metapneumovirus, and adenovirus. Detection by PCR was equivalent in UTM-RT- and CyMol-collected specimens and in self- and staff-collected swabs. Direct fluorescent antibody (DFA) testing was substantially less sensitive (23.3%) than multiplex PCR, and DFA testing from UTM-RT-collected swabs was more sensitive than that from CyMol-collected swabs. These data indicate that an alcohol-based transport medium such as CyMol preserves respiratory virus integrity, rapidly inactivates viruses, and is compatible with PCR-based respiratory diagnostics.

Self-collected oral flocked swabs to measure prevalence of Epstein-Barr Virus antibodies and DNA amongst university students.

Epstein-Barr Virus (EBV) exposure and illness is common in undergraduate university students and may affect academic achievement, social life, and quality of life. We designed a study to measure EBV exposure (EBV-IgG, either Epstein-Barr nuclear antigen 1 (EBNA-1)-IgG or viral capsid antigen (VCA)-IgG) and current viral shedding (EBV-DNA) using self-collected oral swabs among university undergraduate students. Of 184 students enrolled, 129 (70.1%) tested positive for EBV-IgG. Salivopositivity was associated with being in a current relationship, but not with enrollment year. Forty (21.7%) of the participants tested positive for EBV-DNA, which was associated with all symptom scores, including history of sore throat, fever, swollen glands, muscle weakness, and fatigue in the previous 6 months. Our findings suggest that noninvasive, self-collected oral flocked swabs are feasible and potentially valuable for measuring EBV IgG antibodies and DNA.

Development and evaluation of a flocked nasal midturbinate swab for self-collection in respiratory virus infection diagnostic testing.

We developed and evaluated flocked nasal midturbinate swabs obtained from 55 asymptomatic and 108 symptomatic volunteers. Self-collected swabs obtained from asymptomatic volunteers yielded numbers of respiratory epithelial cells comparable to those of staff-collected nasal (n = 55) or nasopharyngeal (n = 20) swabs. Specific viruses were detected in swabs self-collected by 42/108 (38.9%) symptomatic volunteers by multiplex PCR.

Paediatric critical illness associated with respiratory infection: a single-centre, retrospective cohort study.

OBJECTIVES: To describe critically ill children with respiratory infections, classify them by infection syndrome type and determine the prevalence of Mycoplasma pneumoniae detection. STUDY DESIGN: A retrospective, single-centre cohort study. All children aged 2 months-18 years with presumed respiratory infection who were admitted to a tertiary hospital paediatric intensive care unit (PICU) between September 2015 and October 2016 were eligible. Subjects were grouped by clinical syndrome (viral respiratory infection, asthma exacerbation, undifferentiated/uncomplicated pneumonia, pneumonia complicated by effusion/empyema and 'other'). All subjects had nasopharyngeal swabs tested for respiratory viruses, M. pneumoniae and Chlamydia pneumoniae. RESULTS: There were 221 subjects; the median age was 3.1 years; 44% were female; and 78% had medical comorbidities. The majority (75%) was treated with antibiotics, most often ceftriaxone (90% of treated children). Those with any pneumonia were significantly less likely to have a respiratory virus identified in their nasopharynges and had significantly higher C reactive protein (CRP) values than those in the viral infection and asthma groups. There were 10 subjects in whom M. pneumoniae was detected (4.5%, 95% CI 2.2% to 8.2%). Mycoplasma-positive children were older (difference 3.5 years, 95% CI 0.66 to 6.4 years) and had fewer viral coinfections (30% compared with 69%, p=0.02). The prevalence of Mycoplasma infection in children aged >5 years with any pneumonia was 13.2% (95%CI 4.4% to 28%). CONCLUSIONS: The majority of participants had respiratory viruses detected and were treated with broad-spectrum antibiotics. Differences in CRP and viral prevalence were observed between children with different infection syndrome types. M. pneumoniae infection was not rare in school-aged children with pneumonia admitted to the PICU. Attention to antibiotic treatment and rapid diagnostic testing for Mycoplasma in older, critically ill children should be considered to optimise management and avert morbidity and mortality from respiratory infection.

Non-invasive detection of IgG antibodies from common pathogenic viruses using oral flocked swabs.

Salivary antibodies are useful in surveillance and vaccination studies. However, low antibody levels and degradation by endonucleases are problematic. Oral flocked swabs are a potential non-invasive alternative for detecting viral antibodies. Seroprevalence for Cytomegalovirus (CMV), Varicella-Zoster virus (VZV), Epstein-Barr virus (EBV), Measles and Mumps IgG antibodies were determined from 50 matched serum, saliva and swabs samples from healthy volunteers using commercial ELISAs. CMV IgG, VZV IgG, and EBV EBNA-1 IgG, VCA IgG, and Measles IgG swab versus serum sensitivities were 95.8%, 96.0%, 92.1%, 95.5%, 84.5%, respectively, and swabs correlated well with saliva. Sensitivity of Mumps IgG in swabs and saliva was poor at 60.5%, and 68.2%, respectively. Specificities for IgG antibodies were 100% for CMV, EBV and Mumps, but could not be determined for VZV and Measles due to exclusively seropositive volunteers. Except for Mumps IgG, swabs correlate well with serum, are easy to self-collect and are stable at room temperature.

Predictors of Poor Outcomes Among Infants With Respiratory Syncytial Virus-associated Acute Lower Respiratory Infection in Botswana.

Among children 1-23 months of age with respiratory syncytial virus-associated acute lower respiratory infection in Botswana, young age (<6 months), household use of wood as a cooking fuel, moderate or severe malnutrition and oxygen saturation <90% on room air were independent predictors of clinical nonresponse at 48 hours. Among HIV-uninfected infants less than six months of age, HIV exposure was associated with a higher risk of in-hospital mortality.

Comparison of in-house and commercial 16S rRNA sequencing with high-performance liquid chromatography and genotype AS and CM for identification of nontuberculous mycobacteria.

Sequencing of the 16S gene or other targets and line probe assay are in wide use for the identification of nontuberculous mycobacteria. We compared in-house and commercial sequencing with 3 sequence databases against high-performance liquid chromatography (HPLC) and line probe assay (HAIN Genotype AS and CM) for the identification of 84 reference, clinical, and unique strains representing 41 species. Consensus of methods was used as reference standard. Sequencing identification was more specific and flexible than HPLC, but it was limited by database content and quality as well as fragment length. No one database satisfied all requirements. In-house sequencing was lower in cost than commercial sequencing or line probe assay.

Pneumococcal Colonization and the Nasopharyngeal Microbiota of Children in Botswana.

BACKGROUND: Nasopharyngeal colonization precedes infections caused by Streptococcus pneumoniae. A more detailed understanding of interactions between S. pneumoniae and the nasopharyngeal microbiota of children could inform strategies to prevent pneumococcal infections. METHODS: We collected nasopharyngeal swabs from children 1 to 23 months of age in Botswana between August 2012 and June 2016. We tested samples for S. pneumoniae and common respiratory viruses using polymerase chain reaction. We sequenced the V3 region of the bacterial 16S ribosomal RNA gene and used random forest models to identify clinical variables and bacterial genera that were associated with pneumococcal colonization. RESULTS: Mean age of the 170 children included in this study was 8.3 months. Ninety-six (56%) children were colonized with S. pneumoniae. Pneumococcal colonization was associated with older age (P = 0.0001), a lack of electricity in the home (P = 0.02) and household use of wood as a cooking fuel (P = 0.002). Upper respiratory symptoms were more frequent in children with S. pneumoniae colonization (60% vs. 32%; P = 0.001). Adjusting for age, nasopharyngeal microbiota composition differed in colonized and noncolonized children (P = 0.001). S. pneumoniae colonization was associated with a higher relative abundance of Moraxella (P = 0.001) and lower relative abundances of Corynebacterium (P = 0.001) and Staphylococcus (P = 0.03). A decision tree model containing the relative abundances of bacterial genera had 81% sensitivity and 85% specificity for the determination of S. pneumoniae colonization status. CONCLUSIONS: S. pneumoniae colonization is associated with characteristic alterations of the nasopharyngeal microbiota of children. Prospective studies should determine if nasopharyngeal microbial composition alters the risk of pneumococcal colonization and thus could be modified as a novel pneumonia prevention strategy.

Comparison of the RIDASCREEN norovirus enzyme immunoassay to IDEIA NLV GI/GII by testing stools also assayed by RT-PCR and electron microscopy.

RIDASCREEN norovirus enzyme immunoassay (EIA) detected 80.3% of norovirus-infected feces samples compared to 60.6% by IDEIA NLV GI/GII from 228 patients with no false positives by either assay. RT-PCR and electron microscopy percent sensitivity and specificity were 98.5, 100 and 36.4 and 96.9, respectively.