Clinical severity of Mycoplasma pneumoniae (MP) infection is associated with bacterial load in oropharyngeal secretions but not with MP genotype.
Nilsson, Anna LU ; Björkman, Per LU
; Welinder-Olsson, Christina
; Widell, Anders
LU
and Persson, Kenneth
LU
(2010)
In BMC Infectious Diseases
10(39).
- Abstract
- BACKGROUND: Disease severity in Mycoplasma pneumoniae (MP) infection could potentially be related to bacterial factors such as MP genotype (MP1 or MP2; distinguished by different adhesions proteins) or bacterial load in airway secretions. We have compared these parameters in patients who were hospitalized for MP pneumonia, with outpatients with mild MP disease. METHODS: MP bacterial load was measured by real-time PCR in 45 in- and outpatients ("clinical study group") in whom MP DNA had been detected in oropharyngeal secretions by PCR. In addition, genotype and phylogenetic relationships were determined. The phylogenetical assessment was done by partial DNA sequencing of the P1 gene on isolates from 33 patients in the clinical study-group... (More)
- BACKGROUND: Disease severity in Mycoplasma pneumoniae (MP) infection could potentially be related to bacterial factors such as MP genotype (MP1 or MP2; distinguished by different adhesions proteins) or bacterial load in airway secretions. We have compared these parameters in patients who were hospitalized for MP pneumonia, with outpatients with mild MP disease. METHODS: MP bacterial load was measured by real-time PCR in 45 in- and outpatients ("clinical study group") in whom MP DNA had been detected in oropharyngeal secretions by PCR. In addition, genotype and phylogenetic relationships were determined. The phylogenetical assessment was done by partial DNA sequencing of the P1 gene on isolates from 33 patients in the clinical study-group where sufficient DNA was available. The assessment was further extended to isolates from 13 MP-positive family members and 37 unselected MP positive patients from the two subsequent years and two different geographical locations. In total 83 strains were molecular characterized. RESULTS: Mean MP loads were significantly higher in 24 hospitalized patients than in 21 outpatients (1600 vs. 170 genomic equivalents/microL, p = 0.009). This difference remained significant after adjustment for age and days between disease onset and sampling. Hospitalized patients also had higher C-reactive protein levels. Mean levels were 188 vs 20 mg/L (p = 0,001). The genotype assessment showed MP genotype 1 in 17 of the 33 sequenced strains from the clinical study-group, and type 2 in 16 of these patients. Within each genotype, sequence differences were minimal. No association between disease severity and MP genotype was observed. In the extended genotype assessment, MP1 was found in similar proportions. In family contacts it was found in 53% and among patients from the two subsequent years 53% and 40%. CONCLUSIONS: A higher MP bacterial load in throat secretions at diagnosis was associated with more advanced respiratory disease in patients, but MP genotype did not influence disease severity. Both MP genotypes co-circulated during recent outbreaks in Sweden. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1582863
- author
- Nilsson, Anna
LU
; Björkman, Per
LU
; Welinder-Olsson, Christina
; Widell, Anders
LU
and Persson, Kenneth
LU
- organization
- publishing date
- 2010
- type
- Contribution to journal
- publication status
- published
- subject
- in
- BMC Infectious Diseases
- volume
- 10
- issue
- 39
- article number
- 39
- publisher
- BioMed Central (BMC)
- external identifiers
-
- wos:000275622700001
- pmid:20184731
- scopus:77952297731
- pmid:20184731
- ISSN
- 1471-2334
- DOI
- 10.1186/1471-2334-10-39
- language
- English
- LU publication?
- yes
- id
- e6efd653-4625-4550-b238-65d9aaff5939 (old id 1582863)
- alternative location
- http://www.ncbi.nlm.nih.gov/pubmed/20184731?dopt=Abstract
- http://link.springer.com/article/10.1186%2F1471-2334-10-39
- http://www.biomedcentral.com/1471-2334/10/39
- date added to LUP
- 2016-04-04 09:30:34
- date last changed
- 2022-05-01 17:48:19
@article{e6efd653-4625-4550-b238-65d9aaff5939,
abstract = {{BACKGROUND: Disease severity in Mycoplasma pneumoniae (MP) infection could potentially be related to bacterial factors such as MP genotype (MP1 or MP2; distinguished by different adhesions proteins) or bacterial load in airway secretions. We have compared these parameters in patients who were hospitalized for MP pneumonia, with outpatients with mild MP disease. METHODS: MP bacterial load was measured by real-time PCR in 45 in- and outpatients ("clinical study group") in whom MP DNA had been detected in oropharyngeal secretions by PCR. In addition, genotype and phylogenetic relationships were determined. The phylogenetical assessment was done by partial DNA sequencing of the P1 gene on isolates from 33 patients in the clinical study-group where sufficient DNA was available. The assessment was further extended to isolates from 13 MP-positive family members and 37 unselected MP positive patients from the two subsequent years and two different geographical locations. In total 83 strains were molecular characterized. RESULTS: Mean MP loads were significantly higher in 24 hospitalized patients than in 21 outpatients (1600 vs. 170 genomic equivalents/microL, p = 0.009). This difference remained significant after adjustment for age and days between disease onset and sampling. Hospitalized patients also had higher C-reactive protein levels. Mean levels were 188 vs 20 mg/L (p = 0,001). The genotype assessment showed MP genotype 1 in 17 of the 33 sequenced strains from the clinical study-group, and type 2 in 16 of these patients. Within each genotype, sequence differences were minimal. No association between disease severity and MP genotype was observed. In the extended genotype assessment, MP1 was found in similar proportions. In family contacts it was found in 53% and among patients from the two subsequent years 53% and 40%. CONCLUSIONS: A higher MP bacterial load in throat secretions at diagnosis was associated with more advanced respiratory disease in patients, but MP genotype did not influence disease severity. Both MP genotypes co-circulated during recent outbreaks in Sweden.}},
author = {{Nilsson, Anna and Björkman, Per and Welinder-Olsson, Christina and Widell, Anders and Persson, Kenneth}},
issn = {{1471-2334}},
language = {{eng}},
number = {{39}},
publisher = {{BioMed Central (BMC)}},
series = {{BMC Infectious Diseases}},
title = {{Clinical severity of Mycoplasma pneumoniae (MP) infection is associated with bacterial load in oropharyngeal secretions but not with MP genotype.}},
url = {{https://lup.lub.lu.se/search/files/5343474/1590528.pdf}},
doi = {{10.1186/1471-2334-10-39}},
volume = {{10}},
year = {{2010}},
}