Home About us Contact
|
Home About us Contact | ||
|
|
||
Nasopharyngeal Samples (nasopharyngeal + sample)
Selected AbstractsAlloiococcus otitidis,otitis media pathogen or normal bacterial flora?,APMIS, Issue 9 2008KRISTER TANO During the last decade a new potential otitis media pathogen, Alloiococcus otitidis, has been studied. It is still not clear whether this bacterium really is a pathogen, although it has been found in a high percentage of middle ear effusions in children. The present study aimed to investigate the presence of A. otitidis in the nasopharynx and outer ear canals, and to develop a culture method that would make it possible to isolate A. otitidis from these locations. Nasopharyngeal samples (n=129) from children below 6 years were investigated by conventional culture on blood agar plates with 6% saline and rabbit antisera against A. otitidis, and by a PCR method. In the same way, we investigated 10 samples from vestibulum nasi of healthy persons, 68 samples from outer ear canals of patients with acute or chronic ear problems, and 24 samples from outer ear canals of healthy persons. In a rat model of acute otitis media, we instilled living A. otitidis into rat middle ears through the tympanic bulla and evaluated the outcome clinically by otomicroscopy at days 3, 6 and 14. Of the 129 nasopharyngeal cultures, 9 were positive for A. otitidis by PCR, but none by the culture method. Of the 68 samples from patients with running ears, 4 were positive for A. otitidis by PCR, but none by the culture method. Of the 24 healthy ear canals, 7 were positive for A. otitidis by PCR and 3 of them also by the culture method. No A. otitidis could be found from the vestibulum nasi. The rat experiment showed that the reactions in the middle ears were mild; we could not provoke a purulent acute otitis media in any of the rats. There was a 7% prevalence of A. otitidis in children below 6 years. The highest prevalence (29%) was found in outer ear canals of healthy persons, which strongly suggests that A. otitidis is part of the normal bacterial flora of the outer ear canal. The doubtful pathogenicity is also confirmed by the fact that,in the rat model,A. otitidis elicited only a mild response in the middle ear. It was possible to isolate A. otitidis using a blood agar plate with 6% saline. [source] Colony blot assay: a useful method to detect multiple pneumococcal serotypes within clinical specimensFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2004D Bogaert Abstract The efficacy of pneumococal conjugate vaccines in young children may be complicated by serotype replacement. We developed a colony blot assay which enables the identification of re-colonization with novel serotypes (replacement), overgrowth by minor co-colonizing serotypes or suppression of previously predominant vaccine serotype strains as a result of vaccination. This method allows the identification of multiple serotypes in a single specimen in a ratio of 1:1000. In order to demonstrate the potential of our method, we investigated the consecutive nasopharyngeal samples of 26 children who had shown a shift in pneumococcal colonization after conjugate vaccination. Mixed colonization was found once in 15 pre-vaccination samples and four times in 26 post-vaccination samples. In the remaining children ,true replacement' had presumably occurred. Hence, we conclude that the colony blot assay is an easy to apply method, which allows the identification of different pneumococcal serotypes within single clinical specimens. [source] Viral respiratory infections in hospitalized and community control children in Alaska,,JOURNAL OF MEDICAL VIROLOGY, Issue 7 2010Rosalyn J. Singleton Abstract Respiratory syncytial virus (RSV) in Alaska Native children from the Yukon Kuskokwim (YK) Delta is associated with a hospitalization rate five times higher than that reported for the general US child population. The role of other viral respiratory pathogens has not been studied in this population. YK Delta children <3 years of age hospitalized with respiratory infections and same aged community control children were prospectively enrolled between October 2005 and September 2007. Polymerase chain reaction detection of viruses was performed on nasopharyngeal samples. Characteristics of hospitalized and asymptomatic control children were analyzed. From October 2005 to September 2007, 440 hospitalized and 425 control children were analyzed. Respiratory viruses were detected in 90% (395) of hospitalized children: 194 (44%) rhinovirus, 131 (30%) adenovirus, 102 (23%) RSV, 77 (18%) para influenza viruses (PIV), 66 (15%) human metapneumovirus (hMPV), 23 (5%) influenza, and 25 (6%) coronavirus. Fifty-two percent (221) of control children had a virus detected, most commonly rhinovirus (33%), and adenovirus (16%). RSV, PIV, hMPV, and influenza were significantly more common in hospitalized cases than control children, but rhinovirus, adenovirus, and coronavirus were not. RSV and hMPV were associated with higher severity of illness. In this study, RSV remains the most important virus associated with respiratory hospitalization, although hMPV and PIV were also common. RSV and hMPV were associated with more severe illness. Rhinovirus and adenovirus were detected in two-thirds of hospitalized children, but their frequent detection in control children made their role in respiratory hospitalization uncertain. J. Med. Virol. 82:1282,1290, 2010. © 2010 Wiley-Liss, Inc. [source] Study of human metapneumovirus-associated lower respiratory tract infections in Egyptian adultsMICROBIOLOGY AND IMMUNOLOGY, Issue 11 2009Maysaa El Sayed Zaki ABSTRACT There is a deficiency in the data concerning the role of hMPV in lower respiratory tract infections in adults, and until now there has been no data available regarding the prevalence of hMPV in adults in our region. In the present study the association of hMPV with varieties of lower respiratory tract disorders in immunocompetent adult patients, either alone or with bacterial pathogens, has been highlighted. Eighty-eight patients were included in the study. They included 46 males and 42 females with an age range of 38,65 years. Patients presented with lower respiratory tract infections associated with acute exacerbation of asthma (67%), pneumonia (17%), and acute exacerbation of chronic obstructive lung diseases. Sputum and nasopharyngeal samples were obtained from the patients and subjected to a full microbiological study. In addition, detection of hMPV was performed by nested reverse transcriptase polymerase chain reaction. The pathogens isolated were Streptococcus pneumoniae 46.6%, Staphylococci aureus 35.2%, and human metapneumovirus 13.6%. Influenza virus and rhinovirus were each isolated from 4.5% of patients. Human metapneumovirus was associated with S. pneumoniae in 4.5% in studied patients, while in 9.1% it was the only pathogen found in those patients. The commonest clinical condition with significant association with human metapneumovirus was pneumonia. The clinical and laboratory studies demonstrated an association between lower respiratory tract infections in adults and hMPV either as sole pathogen or in association with Streptococcus pneumoniae. It was a common pathogen in community-acquired pneumonia. [source] The Kalgoorlie Otitis Media Research Project: rationale, methods, population characteristics and ethical considerationsPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 1 2008Deborah Lehmann Summary Otitis media (OM) is one of the most common paediatric illnesses for which medical advice is sought in developed countries. Australian Aboriginal children suffer high rates of OM from early infancy. The resultant hearing loss can affect education and quality of life. As numerous factors contribute to the burden of OM, interventions aimed at reducing the impact of single risk factors are likely to fail. To identify key risk factors and understand how they interact in complex causal pathways, we followed 100 Aboriginal and 180 non-Aboriginal children from birth to age 2 years in a semi-arid zone of Western Australia. We collected demographic, obstetric, socio-economic and environmental data, breast milk once, and nasopharyngeal samples and saliva on seven occasions. Ear health was assessed by clinical examination, tympanometry, transient evoked otoacoustic emissions and audiometry. We considered the conduct of our study in relation to national ethical guidelines for research in Aboriginal and Torres Strait Islander health. After 1 year of community consultation, the study was endorsed by local committees and ethical approval granted. Fieldwork was tailored to minimise disruption to people's lives and we provided regular feedback to the community. We saw 81% of non-Aboriginal and 65% of Aboriginal children at age 12 months. OM was diagnosed on 55% and 26% of routine clinical examinations in Aboriginal and non-Aboriginal children respectively. Aboriginal mothers were younger and less educated, fewer were employed and they lived in more crowded conditions than non-Aboriginal mothers. Sixty-four per cent of Aboriginal and 40% of non-Aboriginal babies were exposed to environmental tobacco smoke. Early consultation, provision of a service while undertaking research, inclusion of Aboriginal people as active members of a research team and appropriate acknowledgement will assist in ensuring successful completion of the research. [source] Triplex real-time PCR assay for detection and differentiation of Bordetella pertussis and Bordetella parapertussisAPMIS, Issue 9 2010YINGHUA XU Xu Y, Xu Y, Hou Q, Yang R, Zhang S. Triplex real-time PCR assay for detection and differentiation of Bordetella pertussis and Bordetella parapertussis. APMIS 2010; 118: 685,91. A triplex real-time PCR assay for detection and differentiation of Bordetella pertussis and Bordetella parapertussis was developed. Three targets were used for amplification in a single tube: the insertion sequence IS481 and the pertussis toxin promoter region (ptxP) for B. pertussis, and the insertion sequence IS1001 for B. parapertussis. The performance of this PCR assay was evaluated in parallel in three single-target real-time PCR assays using DNA extracted from B. pertussis and B. parapertussis reference strains and nasopharyngeal swabs taken from 105 patients who had been coughing for more than 7 days. The minimum detection limit of the triplex PCR was one to five colony-forming units (CFU) of B. pertussis and 1 CFU of B. parapertussis per reaction, and the coefficients of both intra- and inter-assay variation were less than 7%. Results were available within 4 h. Of the 105 nasopharyngeal samples, seven were culture positive and 23 were PCR positive for B. pertussis. All culture-positive samples were also PCR positive. Our single-tube triplex real-time PCR assay proved to be sensitive, specific and suitable for simultaneous detection and discrimination of B. pertussis and B. parapertussis. [source] Comparison of real-time PCR and conventional hemi-nested PCR for the detection of Bordetella pertussis in nasopharyngeal samplesCLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2003T. P. Anderson We directly compared a conventional hemi-nested PCR assay with a real-time (LightCycler) PCR assay for the detection of Bordetella pertussis in nasopharyngeal samples. Of the 152 samples tested, 49 (32%) were positive by first-round conventional PCR, 56 (37%) were positive by the hemi-nested PCR assay, and 39 (26%) were positive by the real-time assay. All samples testing positive with the real-time assay were also positive by the hemi-nested assay (both first- and second-round PCR), and all culture-positive samples tested positive by both PCR assays. These results suggest that the hemi-nested assay is more sensitive than the real-time assay for detecting B. pertussis. [source] | |||||||||||||