Evaluation of lytB Gene for Detection of Streptococcus pneumoniae in Isolates and Clinical Specimens by Real-Time PCR

Azarsa, Mohammad; Salami, Seyed Alireza; Pourmand, Mohammad Reza; Forushani, Abbas Rahimi; Kazemian, Hossein

doi:10.5812/jjm.14378

Cited by 6 publications

(3 citation statements)

References 17 publications

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“…The present study results revealed that the PNSP rate in IPD was 35.5%, of which 25.5% and 10% were PRSP (penicillin‐resistant S. pneumoniae ) and PISP (penicillin‐intermediate S. pneumoniae ), respectively. The findings of surveillance studies performed in Iran between the years 2014 and 2019 indicated that 20.8% and 58% of the studied isolates were PNSP 10,11,13,14,27,28 …”

Section: Discussionmentioning

confidence: 96%

“…The findings of surveillance studies performed in Iran between the years 2014 and 2019 indicated that 20.8% and 58% of the studied isolates were PNSP. 10 , 11 , 13 , 14 , 27 , 28 Therefore, the prevalence of nonsusceptibility to penicillin emphasizes the necessity of continued monitoring of the pneumococcal population in Iran. The highest genetic diversity of pbp genes was found in the genetic profile of pbp2x , followed by pbp2b and pbp1a genes.…”

Section: Discussionmentioning

confidence: 99%

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Identification and molecular characterization of penicillin‐nonsusceptible Streptococcus pneumoniae isolates recovered from invasive infections in a pre‐pneumococcal vaccine era

Mosadegh

Ghahfarokhi

Ahmadi

et al. 2022

Clinical Laboratory Analysis

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Background Given the significant role of penicillin‐nonsusceptible Streptococcus pneumoniae in inducing severe infectious diseases, identifying serotypes and genotypes that can mediate antimicrobial resistance has become a pillar of treatment strategies. This study aims to determine the correlation between the minimum inhibitory concentration of antimicrobial agents and amino acid mutations in penicillin‐binding proteins. Moreover, molecular serotyping and multiple‐locus variable number tandem repeat analysis typing were first‐ever performed to characterize the invasive penicillin‐nonsusceptible S. pneumoniae isolates in Iran. Methods Of 149 isolates, antimicrobial susceptibility tests were performed against penicillin, ceftriaxone, and cefotaxime by the MIC Test Strip, and sequence analysis of the pbp genes was performed through PCR‐sequencing method. All penicillin‐nonsusceptible S. pneumoniae isolates were serotyped and genotyped by sequential multiplex PCR and multiple‐locus variable‐number tandem repeat analysis, respectively. Results Among pneumococcal isolates, 53 isolates were classified as penicillin‐nonsusceptible S. pneumoniae, of which 38 (71.7%) and 15 (28.3%) were resistant and intermediate to penicillin, respectively. Furthermore, ceftriaxone‐ and cefotaxime‐nonsusceptible pneumococci constituted 33 (62.2%) and 29 cases (54.7%), respectively. Of note, there were 8 and 41 different serotypes and multiple‐locus variable‐number tandem repeat analysis types, respectively. Conclusions Due to the increasing resistance to antimicrobial agents, the most efficient approach to preventing pneumococcal infection mortality as vaccine‐preventable diseases is focusing on wide‐spectrum vaccination. Based on our findings, the 13‐valent pneumococcal conjugate vaccine could considerably reduce the incidence of invasive pneumococcal diseases due to the high rate of serotype coverage.

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Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 99%

Identification and molecular characterization of penicillin‐nonsusceptible Streptococcus pneumoniae isolates recovered from invasive infections in a pre‐pneumococcal vaccine era

Mosadegh

Ghahfarokhi

Ahmadi

et al. 2022

Clinical Laboratory Analysis

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“…Molecular assays confirmed cultural and biochemical characterization of S. pneumoniae isolates. Isolates were examined for the presence of the lytB gene in DNA extracts by real-time PCR assay as previously described [13].…”

Section: Methodsmentioning

confidence: 99%

Molecular serotyping and genotyping of penicillin non-susceptible pneumococci: the introduction of new sequence types, Tehran, Iran

Azarsa

Moghadam

Rahbar

et al. 2019

New Microbes and New Infections

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The emergence of penicillin non-susceptible Streptococcus pneumoniae (PNSP) isolates can pose significant challenges to today's health-care system. Resistant clonal isolates are disseminated in different regions and countries, and this study was focused on the description of the epidemiological spread of these strains. Clinical samples were collected from individuals admitted to hospitals affiliated to the Tehran University of Medical Sciences, Iran. To investigate the molecular characteristics of PNSP isolates, they were subjected to molecular typing using multi-locus sequence typing (MLST). Serotype distributions of S. pneumoniae isolates were also evaluated by multiplex PCR assay. The most prevalent serotypes in the PNSP isolates were 23F, 19F, 14, 3 and 9V. Two isolates were considered as a non-vaccine serotype. The MLST analysis showed that PNSP isolates belonged to five different clonal complexes (CC180, CC217, CC81, CC63 and CC320) and 42% (5/12) of the sequence types were novel (12936, 12937, 12938, 12939 and 12940). This study indicates the high level of heterogeneity that is present among PNSP isolates. Unexpected high genetic diversity in small populations indicates consecutive diversification of resistant strains.

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The status of Streptococcus pneumoniae in Iran compared to the world: a systematic review

Asadollahi

Darbandi

Lohrasbi

et al. 2021

Reviews and Research in Medical Microbiology

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Introduction:Streptococcus pneumoniae is a leading cause of vaccine-preventable deaths worldwide. Sero-epidemiological data on S. pneumoniae is needed in each country to monitor the burden of this important pathogen in each population. The aim of this study was to evaluate the prevalence, antibiotic resistance, prevalent serotypes and virulence factors of S. pneumoniae in Iran, compared to other parts of the world.Methods:A search via Google Scholar, Scopus, PubMed, ISI, Iranmedex, Magiran, SID and ISC was conducted for original articles investigating S. pneumoniae in Iran. The search terms were ‘Streptococcus pneumoniae’, ‘S. pneumoniae’, ‘prevalence’, ‘antibiotic resistance’, ‘antimicrobial resistance’, ‘typing’, ‘serotyping’, ‘virulence factors’, ‘Iran’.Results:The overall prevalence of invasive pneumococcal disease had an increasing trend in Iran. The most common serotypes amongst Iranian population were 1, 19A, 6A/ 6B, 23F, 14,18C, 20, 19, 3, 6, 9 V, 11A and 19F. Resistance to penicillin and co-trimoxazole had significant decreasing trends whilst resistance to erythromycin was increasing although insignificantly. The most prevalent pneumococcal virulence genes were lytA and pspC.Conclusion:Since pneumococcal serotypes differ in invasiveness, virulence, and antibiotic resistance it is important to closely monitor the changes on evolving serotypes, antibiotic resistance and virulence factors of this pathogen to be able to implement suitable prevention and therapeutic strategies.

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Evaluation of lytB Gene for Detection of Streptococcus pneumoniae in Isolates and Clinical Specimens by Real-Time PCR

Abstract: Background: Streptococcus pneumoniae is a causative agent of morbidity and mortality worldwide. Diagnosis of pneumococcal infection includes conventional culture-based and molecular methods. Differentiation of S. pneumoniae from other mitis group streptococci is not reliable.

Cited by 6 publications

References 17 publications

Identification and molecular characterization of penicillin‐nonsusceptible Streptococcus pneumoniae isolates recovered from invasive infections in a pre‐pneumococcal vaccine era

Identification and molecular characterization of penicillin‐nonsusceptible Streptococcus pneumoniae isolates recovered from invasive infections in a pre‐pneumococcal vaccine era

Molecular serotyping and genotyping of penicillin non-susceptible pneumococci: the introduction of new sequence types, Tehran, Iran

The status of Streptococcus pneumoniae in Iran compared to the world: a systematic review

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