Analysis of amino acid motif of penicillin-binding proteins 1a, 2b, and 2x in invasive Streptococcus pneumoniae nonsusceptible to penicillin isolated from pediatric patients in Casablanca, Morocco

Diawara, Idrissa; Nayme, Kaotar; Katfy, Khalid; Barguigua, Abouddihaj; Kettani-Halabi, Mohamed; Belabbès, Houria; Timinouni, Mohammed; Zerouali, Khalid; Elmdaghri, Naima

doi:10.1186/s13104-018-3719-5

Cited by 13 publications

(16 citation statements)

References 19 publications

(37 reference statements)

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“…Identical mutation patterns were published by Diawara et al previously. The absence of amino acid substitution in the conserved SVVK and KTG motif in this study is identical to previous report, hence suggesting that these two motifs are not involved in penicillin resistance development [44]. On the other hand, no mutations were observed in pbp1a gene of SP2 isolate, and this probably due to pbp1a only involves in developing high penicillin-resistance and it can only be mediated by the presence of mutation on pbp2b and pbp2x [43].…”

Section: Discussionsupporting

confidence: 89%

Molecular detection and genotypic characterisation of Streptococcus pneumoniae isolated from children in Malaysia

Goh

Kee

Jabar

et al. 2020

Pathogens and Global Health

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Streptococcus pneumoniae (S. pneumoniae) is one of the main causative agents of pneumococcal diseases. To date, more than 90 distinct serotypes have been identified. Implementation of vaccines has caused a drastic reduction in vaccine-serotype pneumococcal diseases but increase in cases due to non-vaccine serotype has been observed in Malaysia. However, further investigation on different serotype incidence in Malaysia is needed and the rate of pneumococcal vaccination for new-born babies in Malaysia remains low. The recent emergence of drug-resistant S. pneumoniae (DRSP) has also been a global concern, especially penicillin resistance. This study determined the serotypes of S. pneumoniae strains (n = 95) isolated from nasopharyngeal specimens from children admitted to UMMC from 2013 to 2015. In accordance with previous studies, PCR result showed 40% of NT isolates were successfully typed as 3 less common serotypes, namely 9N/L, 17A, and 23B. The repetitive-element PCR (REP-PCR) result revealed genetic variations among the strains whereby five major clusters were observed at the similarity of 80% by clustering analysis based on fingerprint data. Penicillin-binding proteins (pbps) of selected isolates were studied by PCR and sequencing. Three strains with ≤19-mm diameter zone for Oxacillin Disc Diffusion (ODD) test previously were recorded to have mutation on all pbp1a, pbp2b, and pbp2x with MIC of 4 µg/ml, which were penicillin-intermediate resistance according to the CLSI breakpoints.

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Section: Discussionsupporting

confidence: 89%

Molecular detection and genotypic characterisation of Streptococcus pneumoniae isolated from children in Malaysia

Goh

Kee

Jabar

et al. 2020

Pathogens and Global Health

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“…Penicillin resistant isolates giving positive results for the wild type PBP2b, might be explained by amino acid substitutions near the sequence encoding the downstream KTG motif which can confer PEN resistance 11 or other mutations in different genes such as PBP2x and PBP1a. 33 On the other hand, penicillin-sensitive isolates giving negative result for the wild-type PBP2b need to be further studied and sequenced to uncover the unique genetic resistance profile of the Egyptian pneumococcal isolates that might have different substitutions at other sites. Regarding erythromycin, two susceptible isolates had false-positive mef-A and erm-B genes.…”

Section: Discussionmentioning

confidence: 99%

<p>Serotypes and Antimicrobial Susceptibility of Nasopharyngeal Isolates of <em>Streptococcus pneumoniae</em> from Children Less Than 5 Years Old in Egypt</p>

El-Kholy¹,

Badawy²,

Gad³

et al. 2020

IDR

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Purpose: Streptococcus pneumoniae (S. pneumoniae) is the etiology of severe and lifethreatening infections in children less than 5 years old. Though pneumococcal conjugate vaccines (PCVs) are effective in the prevention of pneumococcal infections, yet they are not included in the National Immunization Program in Egypt pending the identification of pathogenic serotypes. As S. pneumoniae colonization of the pharynx predisposes to pneumonia and invasive pneumococcal disease (IPD) caused by the colonizing serotypes, identification of the nasopharyngeal (NP) serotypes can be a surrogate to the invasive serotypes. In this study, we aimed to 1. Identify the serotypes and antimicrobial susceptibility testing (AST) of Streptococcus pneumoniae colonizing the nasopharynx of Egyptian children younger than 5 years in two successive winter seasons. 2. Correlate the identified serotypes with vaccine coverage of the 13-valent conjugate pneumococcal vaccines (PCV13). 3. Compare the serotypes and AST of S. pneumoniae from NP to those of IPD that were routinely identified in our clinical laboratory during the study period. Materials and Methods: The study was conducted in two successive winter seasons (December 2015-March 2016; December 2016-March 2017). We enrolled 334 children, aged 6 months to 5 years, attending the outpatient general clinics of Cairo University Children Hospital, excluding those with fever, signs of infection, history of antibiotic intake or hospitalization in the preceding month. We tested NP swabs for S. pneumoniae by culture and real-time PCR. Serotyping was performed by sequential multiplex PCR for all positive samples. AST was done to S. pneumoniae isolates by Vitek-2™ (BioMérieux, Marcy-L'Etoile, France). We included routinely detected S. pneumoniae from sterile body sites during the study period, and identified their serotypes and AST. Results: PCR was positive for pneumococci in 217 out of 334 pharyngeal swabs (65%), including 186 typable samples. The most common serotypes were serotypes 1, 6ABC, 19 F, 5 and 18ABC. By culture, we isolated only 110 out of 334 pharyngeal swabs (32.9%). The theoretical coverage of the PCV13 vaccine for the detected serotypes was 77.4%. The AST of NP isolates revealed low susceptibility rates to all antimicrobials except for vancomycin, linezolid, levofloxacin and clindamycin. During the study period, we identified 40 IPD; 21 identified by PCR and 19 by culture. The commonest pneumococcal serotypes were 1, 18ABC, 6ABC and 5. The PCV13 coverage was 75%. By Vitek-2, the isolates showed 100%, 100%, 94.7%, 89.5%, 84.2%, 84.2% and 78.9% susceptibility to vancomycin, linezolid, clindamycin, levofloxacin, penicillin, cefotaxim and erythromycin, respectively. Conclusion: Based on the serotype vaccine coverage and the emerging antimicrobial resistance of S. pneumoniae, PCVs will be valuable to Egyptian children.

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“…Mutational changes to PBPs that are associated with resistance act by reducing the affinities of PBPs for β-lactams [129][130][131][132]. PBP3 is encoded by the ftsI gene.…”

Section: Target-site Modification: Changes To Pbp3mentioning

confidence: 99%

β-lactam Resistance in Pseudomonas aeruginosa: Current Status, Future Prospects

Glen

Lamont

2021

Pathogens

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Pseudomonas aeruginosa is a major opportunistic pathogen, causing a wide range of acute and chronic infections. β-lactam antibiotics including penicillins, carbapenems, monobactams, and cephalosporins play a key role in the treatment of P. aeruginosa infections. However, a significant number of isolates of these bacteria are resistant to β-lactams, complicating treatment of infections and leading to worse outcomes for patients. In this review, we summarize studies demonstrating the health and economic impacts associated with β-lactam-resistant P. aeruginosa. We then describe how β-lactams bind to and inhibit P. aeruginosa penicillin-binding proteins that are required for synthesis and remodelling of peptidoglycan. Resistance to β-lactams is multifactorial and can involve changes to a key target protein, penicillin-binding protein 3, that is essential for cell division; reduced uptake or increased efflux of β-lactams; degradation of β-lactam antibiotics by increased expression or altered substrate specificity of an AmpC β-lactamase, or by the acquisition of β-lactamases through horizontal gene transfer; and changes to biofilm formation and metabolism. The current understanding of these mechanisms is discussed. Lastly, important knowledge gaps are identified, and possible strategies for enhancing the effectiveness of β-lactam antibiotics in treating P. aeruginosa infections are considered.

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Analysis of amino acid motif of penicillin-binding proteins 1a, 2b, and 2x in invasive Streptococcus pneumoniae nonsusceptible to penicillin isolated from pediatric patients in Casablanca, Morocco

Cited by 13 publications

References 19 publications

Molecular detection and genotypic characterisation of Streptococcus pneumoniae isolated from children in Malaysia

Molecular detection and genotypic characterisation of Streptococcus pneumoniae isolated from children in Malaysia

<p>Serotypes and Antimicrobial Susceptibility of Nasopharyngeal Isolates of <em>Streptococcus pneumoniae</em> from Children Less Than 5 Years Old in Egypt</p>

β-lactam Resistance in Pseudomonas aeruginosa: Current Status, Future Prospects

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