A highly sensitive immuno-PCR assay for detecting Group A Streptococcus

2003 ◽  
Vol 279 (1-2) ◽  
pp. 101-110 ◽  
Author(s):  
Huining Liang ◽  
Susan E. Cordova ◽  
Thomas L. Kieft ◽  
Snezna Rogelj
2021 ◽  
Author(s):  
Jeffrey S. Rush ◽  
Prakash Parajuli ◽  
Alessandro Ruda ◽  
Jian Li ◽  
Amol A. Pohane ◽  
...  

The cell wall of the human bacterial pathogen Group A Streptococcus (GAS) consists of peptidoglycan decorated with the Lancefield group A carbohydrate (GAC). GAC is a promising target for the development of GAS vaccines. In this study, employing chemical, compositional, and NMR methods, we show that GAC is attached to peptidoglycan via glucosamine 1-phosphate. This structural feature makes the GAC-peptidoglycan linkage highly sensitive to cleavage by nitrous acid and resistant to mild acid conditions. Using this characteristic of the GAS cell wall, we identify PplD as a protein required for deacetylation of linkage N-acetylglucosamine (GlcNAc). X-ray structural analysis indicates that PplD performs catalysis via a modified acid/base mechanism. Genetic surveys in silico together with functional analysis indicate that PplD homologs deacetylate the polysaccharide linkage in many streptococcal species. We further demonstrate that introduction of positive charges to the cell wall by GlcNAc deacetylation protects GAS against host cationic antimicrobial proteins.


1998 ◽  
Vol 36 (6) ◽  
pp. 1769-1771 ◽  
Author(s):  
Lisa Louie ◽  
Andrew E. Simor ◽  
Marie Louie ◽  
Allison McGeer ◽  
Donald E. Low

This study evaluated a PCR assay for detection of the streptococcal pyrogenic exotoxin B (speB) gene from tissue biopsy specimens of patients with necrotizing fasciitis. speB was detected in specimens from all 10 patients with necrotizing fasciitis due to group A streptococcus. The assay was negative for all 11 patients without culture or serologic evidence of streptococcal infection. These results suggest that the detection of speBby PCR may be useful for confirming group A streptococcal infection when cultures are negative or not available.


2020 ◽  
Vol 10 (1) ◽  
pp. 111-120
Author(s):  
S. Yu. Kombarova ◽  
A. M. Bichucher ◽  
Y. L. Soldatsky ◽  
R. Yu. Yunusova ◽  
T. A. Skirda ◽  
...  

Meningococcal, pneumococcal, streptococcal A and Haemophilus influenzae infections are manifested in different clinical forms, ranging from bacterial carriage to generalized life-threatening conditions. However, a connection between bacterial carriage and disease development has not been fully explored. A PCR assay was performed with adenoid biopsy samples collected from 112 children after planned adenotomy to detect Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus pyogenes, H. influenzae carriage. A DNA specific to at least one of the four studied microbial species was found in 104 samples (92.86%) so that: meningococcal DNA was detected in one sample (0.9%), pneumococcal — in 98 (87.5%), H. influenzae — in 19 (16.96%), and streptococcal A — in 42 (37.5%) samples. However, none of these species was found in 8 children (7.14%). A sole S. pneumoniae was detected in 54 samples (48.2%), whereas S. pyogenes — in 5 samples (4.5%). Moreover, two bacterial species were simultaneously as follows: N. meningitidis and S. pneumoniae — in 1 sample (0.9%), S. pneumoniae and H. influenzae — in 7 samples (6.3%); H. influenzae and S. pyogenes — in 1 sample (0.9%); S. pneumoniae and S. pyogenes — in 25 samples (22.3%). A triple combination consisting of S. pneumoniae, H. influenzae and S. pyogenes bacteria were detected together in 11 patients (9.8%). Meningococcal serogrouping revealed no connection with any of the 6 most common global serogroups responsible for epidemic incidence rise (A, B, C, W-135, X, Y). A clear tendency for prevalence of S. pyogenes DNA in adenoid pediatric biopsies in children diagnosed with “Adenoids and tonsils hypertrophy” vs. “Adenoids hypertrophy” was observed. It is noteworthy, a high relative prevalence of pneumococcal carriage (87.5%), found by us was of special importance. Pediatric carriers serving as a reservoir for virulent pneumococcal species pose a threat both for themselves and surrounding people. Thus, PCR-based data of adenoid biopsies may be a promising approach for future studies, as a potential to identify live viable but nonculturable bacteria in clinical specimens will contribute to a more accurate assessment of carriage rate of meningococci, pneumococci, H. influenzae and group A streptococci.


2020 ◽  
pp. 64-70
Author(s):  
Anastasiya Laknitskaya

Currently, one of the priority medical and social problems is the optimization of treatment methods for pyoderma associated with Streptococcus pyogenes — group A streptococcus (GAS). To date, the proportion of pyoderma, the etiological factor of which is Streptococcus pyogenes, is about 6 % of all skin diseases and is in the range from 17.9 to 43.9 % of all dermatoses. Role of the bacterial factor in the development of streptococcal pyoderma is obvious. Traditional treatment complex includes antibacterial drugs selected individually, taking into account the antibiotic sensitivity of pathognomonic bacteria, and it is not always effective. Currently implemented immunocorrection methods often do not take into account specific immunological features of the disease, the individual, and the fact that the skin performs the function of not only a mechanical barrier, but it is also an immunocompetent organ. Such an approach makes it necessary to conduct additional studies clarifying the role of factors of innate and adaptive immunity, intercellular mediators and antioxidant defense system, that allow to optimize the treatment of this pathology.


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