Incidence and Pathogenic Effect of
            <i>Streptococcus pseudopneumoniae</i>

Harf-Monteil, Colette; Granello, Carole; Brun, Cécile; Monteil, H.; Riegel, Philippe

doi:10.1128/jcm.02643-05

Cited by 37 publications

(33 citation statements)

References 7 publications

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“…Patients with S. pseudopneumoniae infection may be more likely to have a history of chronic obstructive pulmonary disease (COPD) or an exacerbation of COPD than patients with S. pneumoniae infection (17). Another study also described a potential pathogenic role, since infection with several S. pseudopneumoniae strains killed infected mice (14). The development of an assay that can discriminate S. pseudopneumoniae from S. pneumoniae and other mitis group streptococci and that can easily be implemented in routine diagnostic procedures will result in more insight into the clinical importance of S. pseudopneumoniae.…”

mentioning

confidence: 98%

Evaluation of Several Biochemical and Molecular Techniques for Identification of Streptococcus pneumoniae and Streptococcus pseudopneumoniae and Their Detection in Respiratory Samples

et al. 2012

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The identification and detection of mitis group streptococci, which contain Streptococcus pneumoniae, have been hampered by the lack of sensitive and specific assays. In this study, we evaluated several biochemical and molecular assays for the identification of S. pneumoniae and Streptococcus pseudopneumoniae and their distinction from other mitis group streptococci using a collection of 54 isolates obtained by the routine culturing of 53 respiratory specimens from patients with community-acquired pneumonia. The combined results of the biochemical and molecular assays indicated the presence of 23 S. pneumoniae, 2 S. pseudopneumoniae, and 29 other mitis group streptococcal isolates. The tube bile solubility test that is considered gold standard for the identification of S. pneumoniae showed concordant results with optochin susceptibility testing (CO 2 atmosphere) and a real-time multiplex PCR assay targeting the Spn9802 fragment and the autolysin gene. Optochin susceptibility testing upon incubation in an O 2 atmosphere, bile solubility testing by oxgall disk, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and sequence analysis of the tuf and rpoB genes resulted in several false-positive, false-negative, or inconclusive results. The S. pseudopneumoniae isolates could be identified only by molecular assays, and the multiplex real-time PCR assay was concluded to be most convenient for the identification of S. pneumoniae and S. pseudopneumoniae isolates. Using this method, S. pneumoniae and S. pseudopneumoniae DNA could be detected in the respiratory samples from which they were isolated and in an additional 11 samples from which only other streptococci were isolated. S treptococcus pneumoniae is a major cause of community-acquired pneumonia (CAP). There is no true gold standard for S. pneumoniae identification, but the bile solubility test has been shown to have a high level of accuracy and is frequently used for the identification of S. pneumoniae (18). Since this test is relatively time-consuming and sometimes difficult to interpret, several other conventional biochemical and phenotypic tests, like Gram stain morphology, optochin susceptibility, colony morphology, and alpha-hemolysis on sheep blood agar, are currently applied as part of routine procedures in the clinical microbiology laboratory. S. pneumoniae belongs to the mitis group of streptococci, and several molecular assays have been applied in an attempt to discriminate S. pneumoniae from other mitis group streptococci. A variety of genes has been used as target for a (real-time) PCR assay to detect S. pneumoniae, including genes encoding the virulence factors autolysin (lytA) and pneumolysin (ply) and the DNA fragment Spn9802 (1,4,7,16,22,25,32). However, most of these PCR assays are not able to discriminate S. pneumoniae from the recently discovered Streptococcus pseudopneumoniae and other mitis group streptococci. As an alternative approach, sequence analysis of several genes has been used for the species-level identifica...

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confidence: 98%

Evaluation of Several Biochemical and Molecular Techniques for Identification of Streptococcus pneumoniae and Streptococcus pseudopneumoniae and Their Detection in Respiratory Samples

et al. 2012

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“…COPD with infected exacerbation and previous hospitalization with COPD were significantly associated with increase in the acquisition of S. pseudopneumoniae in spite of large number of studied cases suffering from COPD in this research. The association of COPD with S. pseudopneumoniae infection has been documented by previous studies (Keith et al, 2006;Harf-Monteil et al, 2006), however other studies have recorded that S. pseudopneumoniae were more frequently associated with bronchitis and pneumonia rather than COPD (Laurens et al, 2012). To determine the actual role of S. pseudopneumoniae in COPD exacerbation, cohort studies for patients during periods of exacerbation and stability of COPD is recommended to observe the appearance of new S. pseudopneumoniae isolates in the exacerbation periods that could confirm the association of infection with new bacterial strains and COPD exacerbation (Sethi et al, 2002).…”

Section: Discussionmentioning

confidence: 88%

“…Isolated organisms were identified according to standard microbiological methods. Alpha hemolytic colonies were selected for Gram staining, colonies that showed Gram positive cocci arranged in pairs or chains were subjected to further identification by pneumococcal capsule detection test (capsules were detected by observing a halo around Pneumococci with India ink at ×400 magnification) (Harf-Monteil et al, 2006), optochin susceptibility and bile solubility tests.…”

Section: Culture and Identificationmentioning

confidence: 99%

Streptococcus pseudopneumoniae as an emerging pathogen from patients with respiratory diseases

El-Kazzaz¹,

El-Khier²,

Arram³

2017

Afr. J. Microbiol. Res.

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Streptococcus pseudopneumoniae is a mischaracterized species of Streptococci that is usually overlooked during examination of sputum samples of patients with chest infections. The association of this organism with lower respiratory tract diseases is still unclear and its isolation and description is underestimated in our locality. To our knowledge, there are no published studies on the isolation of S. pseudopneumoniae from pathological specimens in Egypt. The aims of this study were to isolate S. pseudopneumoniae from sputum specimens of patients admitted to Chest Department of Mansoura University Hospitals (MUHs) and to differentiate it from Streptococcus pneumoniae and other viridans group Streptococci, also to determine its prevalence and associated risk factors. Sixteen isolates of S. pseudopneumoniae were diagnosed phenotypically by optochin susceptibility and bile solubility tests followed by genotypic characterization by multiplex polymerase chain reaction (PCR). All of the isolates were subjected to antibiotic susceptibility testing using the disk diffusion method. The prevalence of S. pseudopneumoniae among studied patients was 4.9% (16/329). All of the examined isolates were found to be positive for aliB-like ORF2 and negative for cpsA and lytA genes by multiplex PCR. Elevated resistance rate of the isolates was recorded for erythromycin, penicillin and co-trimoxazole. Infection by S. pseudopneumoniae was found to be significantly associated with Chronic Obstructive Pulmonary Diseases (COPD). Although, S. pseudopneumoniae recorded a low prevalence in this study, their elevated antibiotic resistance together with the association with COPD and their pure isolation from sputum samples underline the necessity of spending more effort for their detection and characterization in the microbiology laboratories.

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“…pneumoniae in the respiratory tract is low (1% to 12%) (20)(21)(22), and it is more frequently present in sputum than in the nasopharynx (23). Moreover, our purpose here was not to evaluate this RT-PCR assay but to assess the lyophilization of DNA.…”

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confidence: 99%

Cost-Effective Pooling of DNA from Nasopharyngeal Swab Samples for Large-Scale Detection of Bacteria by Real-Time PCR

et al. 2015

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We investigated the potential of pooling DNA from nasopharyngeal specimens to reduce the cost of real-time PCR (RT-PCR) for bacterial detection. Lyophilization is required to reconcentrate DNA. This strategy yields a high specificity (86%) and a high sensitivity (96%). We estimate that compared to individual testing, 37% fewer RT-PCR tests are needed. R eal-time PCR (RT-PCR) is an essential tool for routine diagnostics and large epidemiological studies of infectious diseases (1, 2). However, its cost remains significant and limits its use. To reduce it, samples can be pooled (3)(4)(5). This idea was suggested by Dorfman in 1943 (6) and has been used for the serological diagnosis of infectious diseases. Pooling samples is also an efficient way to screen for the nucleic acids of viruses, bacteria, or parasites (4,5,(7)(8)(9)(10)(11)(12)(13)(14)(15). However, pooling can decrease the sensitivity of assays due to the dilution of the samples, which is problematic in clinical diagnostics (16). Here, we investigated the potential of pooling DNA from clinical specimens using lyophilization to concentrate the pooled DNA and maintain the sensitivity of RT-PCR.We screened 2,380 nasopharyngeal swabs (Remel, USA) by RT-PCR to detect their rates of Streptococcus pneumoniae, Haemophilus influenzae, and Klebsiella pneumoniae carriage. DNA was extracted using a Macherey-Nagel NucleoSpin-96 kit. A total of 119 pools containing 80 l of DNA from 20 patients was frozen for 4 h at Ϫ20°C, lyophilized using a Lyovac GTZ instrument (Leybold Heraeus, France), and redissolved in 80 l of sterile water. The effectiveness of lyophilization was verified with pool controls, including one positive sample with a known threshold cycle (C T ) value for each bacterium. The specificities of the primers and probes (17, 18) were verified in silico by conducting a BLAST search in GenBank and performing RT-PCR on 10 to 15 closely related bacterial strains present in the respiratory tract (see Tables S1 and S2 in the supplemental material). RT-PCR was performed using 5 l of DNA per reaction and a 7900HT thermocycler (Applied Biosystems). Nuclease-free water was used as a negative control, and DNA from a clinical strain was used as a positive control. The cutoff C T value for positive results was Յ38. Each sample was also tested individually. The DNA extraction quality of each pool was verified by RT-PCR targeting the human beta-actin gene (19).The prevalences for the individual samples were 9% (215/ 2,380) for S. pneumoniae, 7% (169/2,380) for H. influenzae, and 4% (95/2,380) for K. pneumoniae. Among the pools tested, 69% (82/119) were positive for S. pneumoniae, 53% (63/119) were positive for H. influenzae, and 53% (63/119) were positive for K. pneumoniae (Table 1). Among them, 184/357 (52%) were truepositive results and 142/357 (40%) were true-negative results. However, 24/357 (7%) were false positives (negative individual samples), and 7/357 (2%) negative pools contained positive individual specimens, yielding false negatives (see Table S3 in the sup...

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Incidence and Pathogenic Effect of Streptococcus pseudopneumoniae

Cited by 37 publications

References 7 publications

Evaluation of Several Biochemical and Molecular Techniques for Identification of Streptococcus pneumoniae and Streptococcus pseudopneumoniae and Their Detection in Respiratory Samples

Evaluation of Several Biochemical and Molecular Techniques for Identification of Streptococcus pneumoniae and Streptococcus pseudopneumoniae and Their Detection in Respiratory Samples

Streptococcus pseudopneumoniae as an emerging pathogen from patients with respiratory diseases

Cost-Effective Pooling of DNA from Nasopharyngeal Swab Samples for Large-Scale Detection of Bacteria by Real-Time PCR

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