Penicillin-binding proteins (PBPs) are the target of β-lactam antibiotics (the major treatment for Streptococcus pneumoniae infections), and mutations in PBPs are considered as a primary mechanism for the development of β-lactam resistance in S. pneumoniae. This study was conducted to investigate the mutations in the PBPs of clinical S. pneumoniae isolates in Hangzhou, China, in correlation with β-lactam resistance. Results showed that 19F was the predominant serotype (7/27) and 14 of the S. pneumoniae isolates were resistant to both penicillin G and cephalosporin. Genotyping results suggested that β-lactam-resistant isolates primarily exhibited single-site mutations in both the STMK and SRNVP motifs of pbp1a in combination with double-site mutations in the STMK motif of pbp2x, which might be the primary mechanisms underlying the β-lactam resistance of the isolates in this study.
Anti-Bacterial Agents ; pharmacology ; China ; epidemiology ; Drug Resistance, Bacterial ; Humans ; Pneumococcal Infections ; epidemiology ; microbiology ; Streptococcus pneumoniae ; drug effects ; genetics ; beta-Lactams ; pharmacology

The carriage rate and serotype distribution of Streptococcus pneumoniae (S. pneumoniae) in a healthy population in China remains unclear. In this study, we collected the oropharyngeal swabs from 513 individuals in Xinjiang, China. Real-time PCR targeting the lytA gene and 12 serotypes were assessed to identify S. pneumoniae carriage. The total carriage rate of S. pneumoniae was 70.4% (361/513). The most prevalent serotypes were 19B/F, 18B/C, 5, and 6A/B. The highest carriage rate of S. pneumoniae was noted in children aged 6-10 years (88.6%), which merits further attention. The co-colonization rate of two or more S. pneumoniae serotypes was 79.8% (264/331). This study aimed to investigate the baseline pneumococcal carriage rate among healthy individuals in China to improve our understanding of the epidemiology of S. pneumoniae.
Adolescent ; Adult ; Carrier State ; epidemiology ; microbiology ; Child ; Child, Preschool ; China ; epidemiology ; Cross-Sectional Studies ; Female ; Humans ; Infant ; Male ; Middle Aged ; Pneumococcal Infections ; epidemiology ; microbiology ; Prevalence ; Real-Time Polymerase Chain Reaction ; Serogroup ; Streptococcus pneumoniae ; classification ; genetics ; isolation & purification ; Young Adult

OBJECTIVETo investigate the prokaryotic expression of proteins pneumococcal endopeptidase O (PepO) and pneumococcal surface adhesin A (PsaA) in Streptococcus pneumoniae and their immunoprotective effect as vaccine candidate proteins.

METHODSSpecific primers of target gene fragments were designed, and then PCR amplification was performed to establish recombinant plasmids pET28a(+)-pepO and pET28a(+)-psaA, which were transformed into host cells, Escherichia coli BL21 and DE3, respectively, to induce expression. Highly purified target proteins PepO and PsaA were obtained after purification. Mucosal immunization was performed for BALB/c mice and specific antiserum was prepared. ELISA was used to measure the antibody titer, and Western blot was used to analyze the specificity of the antiserum of target proteins. The mice were randomly divided into negative control group, PepO group, PsaA group, and PepO+PsaA combined immunization group, with 18 mice in each group. The models of different serotypes of Streptococcus pneumoniae infection were established to evaluate the immunoprotective effect of target proteins used alone or in combination.

RESULTSThe target proteins PepO and PsaA were successfully obtained and Western blot demonstrated that the antiserum of these proteins had good specificity. There was no significant difference in the titers of IgA in saliva and IgG in serum between the PepO group and the combined immunization group (P>0.05); however, these two groups had significantly higher antibody titers than the PsaA group (P<0.05). The PepO, PsaA, and combined immunization groups had significantly higher protection rates for mice infected with Streptococcus pneumoniae D39 and CMCC31436 in the nasal cavity than the negative control group (P<0.05). The PepO and combined immunization groups had a significantly higher protection rate for mice infected with Streptococcus pneumoniae D39 than the PsaA group (P<0.05). The results of colonization experiment showed that compared with the control group, the PepO, PsaA, and combined immunization groups showed a significant reduction in the colonization of Streptococcus pneumoniae (CMCC31693 and CMCC31207) in the nasopharynx and lung (P<0.05). The combined immunization group showed a better effect on reducing the colonization of CMCC31207 in the lung than the PepO and PsaA alone groups.

CONCLUSIONSCombined PepO/PsaA vaccines may produce a better protective effect by mucosal immunization compared with the vaccine used alone in mice. The combined vaccines can effectively reduce the colonization of Streptococcus pneumoniae in the nasopharynx and lung. Therefore, such protein vaccines may have a great potential for research and development.

Adhesins, Bacterial ; immunology ; Animals ; Antibodies, Bacterial ; analysis ; Bacterial Proteins ; immunology ; Female ; Immunization ; Lipoproteins ; immunology ; Lung ; microbiology ; Metalloendopeptidases ; immunology ; Mice ; Mice, Inbred BALB C ; Pneumococcal Infections ; prevention & control ; Pneumococcal Vaccines ; immunology ; Saliva ; immunology

This study was performed to measure early changes in the serotype distribution of pneumococci isolated from children with invasive disease during the 3-year period following the introduction of 10- and 13-valent pneumococcal conjugate vaccines (PCVs) in Korea. From January 2011 to December 2013 at 25 hospitals located throughout Korea, pneumococci were isolated among children who had invasive pneumococcal disease (IPD). Serotypes were determined using the Quellung reaction, and the change in serotype distribution was analyzed. Seventy-five cases of IPD were included. Eighty percent of patients were aged 3-59 months, and 32% had a comorbidity that increased the risk of pneumococcal infection. The most common serotypes were 19A (32.0%), 10A (8.0%), and 15C (6.7%). The PCV7 serotypes (4, 6B, 9V, 14, 18C, 19F, 23F, and 6A) accounted for 14.7% of the total isolates and the PCV13 minus PCV7 types (1, 3, 5, 7F and 19A) accounted for 32.0% of the total isolates. Serotype 19A was the only serotype in the PCV13 minus PCV7 group. The proportion of serotype 19A showed decreasing tendency from 37.5% in 2011 to 22.2% in 2013 (P = 0.309), while the proportion of non-PCV13 types showed increasing tendency from 45.8% in 2011 to 72.2% in 2013 (P = 0.108). Shortly after the introduction of extended-valent PCVs in Korea, serotype 19A continued to be the most common serotype causing IPD in children. Subsequently, the proportion of 19A decreased, and non-vaccine serotypes emerged as an important cause of IPD. The impact of extended-valent vaccines must be continuously monitored.
Adolescent ; Bacteremia/complications/diagnosis ; Child ; Child, Preschool ; Female ; Hospitals ; Humans ; Infant ; Male ; Pneumococcal Infections/microbiology/*prevention & control ; Pneumococcal Vaccines/*immunology ; Republic of Korea ; Serotyping ; Streptococcus pneumoniae/*classification/isolation & purification ; Vaccines, Conjugate/*immunology

In Republic of Korea, a 7-valent pneumococcal conjugated vaccine (PCV7) was licensed for use in infants in 2003, and 13-valent PCV (PCV13) replaced it since 2010. We investigated trends in serotype distribution and antibiotic susceptibility of pneumococcal isolates from adult patients with invasive pneumococcal diseases (IPD). Invasive pneumococcal isolates from adult patients of ≥ 16 years of age were collected from 1997 to 2012. Serotypes of the isolates were determined by the Quellung reaction. Distribution of serotypes was analyzed according to the vaccine types. Antibiotic susceptibility was tested by using E-test strips. A total of 272 invasive pneumococcal isolates were included. The most common serotypes were serotype 19F (8.5%, 23/272), and serotype 3 (8.1%, 22/272), and 24.6% (67/272) of the isolates were of non-vaccine serotypes. Of the 272 isolates, 2.6% (7/272) were penicillin MICs of ≥ 4 µg/mL. The proportion of the PCV13 serotypes decreased from 63.3% (50/79) in 1997-2003 to 48.6% (17/35) in 2011-2012, whereas that of non-vaccine serotypes was 26.6% (21/79) and 25.7% (9/35), respectively, for the same periods. The proportion of the PCV13 serotypes showed a decreasing trend among adult patients with IPD over the study period.
Adolescent ; Adult ; Aged ; Anti-Infective Agents/*pharmacology/therapeutic use ; Ceftriaxone/pharmacology/therapeutic use ; Female ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Penicillins/pharmacology/therapeutic use ; Pneumococcal Infections/drug therapy/*microbiology/mortality ; Republic of Korea ; Serogroup ; Serotyping ; Streptococcus pneumoniae/*drug effects/isolation & purification ; Young Adult

BACKGROUND: The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide. METHODS: We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics. RESULTS: Antibiotic susceptibility tests revealed that 100% and 47% isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84%) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16%) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes. CONCLUSIONS: The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; DNA, Bacterial/metabolism ; Drug Resistance, Multiple, Bacterial/*genetics ; Erythromycin/*pharmacology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Phenotype ; Pneumococcal Infections/microbiology/pathology ; Polymerase Chain Reaction ; Streptococcus pneumoniae/*drug effects/*genetics/isolation & purification ; Tetracycline/pharmacology

OBJECTIVETo investigate nasopharyngeal carriage rate, antimicrobial resistance and serotype distribution of Streptococcus pneumoniae among children with upper respiratory infection.

METHODSNasopharygeal swabs were collected from children with upper respiratory infection visiting the outpatient department of Beijing Children′s Hospital between March 2013 and February 2014. The antibiotic susceptibility was tested by Etest method, and the serotype was determined by Quellung reaction.

RESULTSThe nasopharyngeal carriage rate for Streptococcus pneumoniae was 23.8% (699/2 941). One hundred isolates were randomly chosen for antimicrobial susceptiblity test and serotyping. Up to 98.0% isolates were susceptible to parenteral penicillin. The susceptible rate against oral penicillin, however, was 33.0%. The non-susceptible rate to erythromycin and azithromycin was 97.0%. The multi-drug resistance rate was up to 86.0%. The common serotypes were 6A(12.0%), 19F(12.0%), 6B(10.0%), 23F(9.0%) and 14(8.0%). The coverage rates of 7-, 10- and 13-valent pneumococcal conjugate vaccine were 41.0%, 42.0% and 59.0% respectively.

CONCLUSIONSAbout 25% of children with upper respiratory infection are nasopharyngeal colonized by Streptococcus pneumoniae. The isolates show a high antimicrobial resistance. The 13-valent pneumococcal conjugate vaccine covers about 60.0% of the isolates.

Adolescent ; Carrier State ; epidemiology ; microbiology ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Nasopharynx ; microbiology ; Pneumococcal Vaccines ; immunology ; Respiratory Tract Infections ; microbiology ; Serotyping ; Streptococcus pneumoniae ; classification ; drug effects ; isolation & purification

BACKGROUNDErythromycin-resistant Streptococcus pneumoniae isolates that causing invasive pneumococcal diseases (IPD) in Chinese children remain uncharacterized. This study aims to identify the resistance genes associated with erythromycin resistance and to determine the genetic relationships of IPD isolates in Chinese children.

METHODSA total of 171 S. pneumoniae strains were isolated from 11 medical centers in China from 2006 to 2008. All the isolates were characterized via serotyping and antibiotic susceptibility determination. The erythromycin-resistant isolates were further characterized via ermB and mefA gene detection, multi-locus sequence typing analysis, and pulsed-field gel electrophoresis.

RESULTSA total of 164 (95.9%) isolates showed resistance to erythromycin, of which 162 strains with high high-level resistance (MIC ≥ 256 µg/ml). A total of 104 (63.4%) isolates carry the ermB gene alone, whereas 59 (36.0%) harbor both ermB and mefA genes. Of the 59 strains, 54 were of serotypes 19A and 19F and were identified as highly clonal and related to the Taiwan(19F)-14 clone.

CONCLUSIONSThe erythromycin resistance rate in IPD isolates is significantly high and is predominantly mediated by the ermB gene. Isolates that carry both ermB and mefA genes are predominantly of serotypes 19A and 19F.

Adolescent ; Anti-Bacterial Agents ; pharmacology ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Erythromycin ; pharmacology ; Humans ; Infant ; Multilocus Sequence Typing ; Pneumococcal Infections ; microbiology ; Serotyping ; Streptococcus pneumoniae ; classification ; drug effects ; genetics ; isolation & purification

OBJECTIVETo study the clinical characteristics of Streptococcus pneumonia-associated hemolytic uremic syndrome (SP-HUS) in children.

METHODClinical and laboratory data of a pediatric case of SP-HUS were retrospectively analyzed and the key points of diagnosis and therapy were reviewed.

RESULTAn 18-month old girl was admitted with chief complaint of fever and cough for 5 days combined with mild labored breath. Breath sound was found weakened in right lung with lower lobe dullness on percussion. Laboratory tests revealed: WBC 3.7×10(9)/L, Hb 83 g/L, PLT 11×10(9)/L, C-reactive protein (CRP) > 180 mg/L. Morphological study of the RBCs showed marked anisocytosis and schistocytosis. Urinalysis showed 42.66 RBCs per high-power field, occult blood (+++), proteinura (++++). Streptococcus pneumoniae was isolated from blood, pleural fluid and sputum. Serotyping with simplified chessboard system was 3. The direct Coombs test was positive. Serum complement levels (C3 and C4) were depressed at 0.699 g/L, 0.064 g/L, respectively. Chest X-ray showed pleural effusion and infection of the right hemothorax. The computerized tomographic scan of the chest revealed pneumatoceles in the right lower lobe. The diagnosis on admission we considered was SP-HUS. Intravenous antibiotic therapy (vancomycin + cefoperazone/sulbactam) was administered. The renal replacement theraphy was administered to maintain electrolyte and fluid balances and adequate nutrition. Transfusions of washed red blood cells were administered to correct the anemia. One month after admission the patient was good with recovery. Liver and renal function recovered and the pneumonia was resolving, anemia and platelets were corrected. The direct Coombs test turned to be negative. Serum complement levels (C3 and C4) were normal. After 3-month follow-up, no clinical anomalies were detected.

CONCLUSIONSP-HUS should be suspected when the following occurs in the context of pneumococcal infections: microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure and a positive Coombs test result. Serotype 3 of SP was associated with HUS.

Anti-Bacterial Agents ; therapeutic use ; Biomarkers ; analysis ; Coombs Test ; Female ; Hemolytic-Uremic Syndrome ; diagnosis ; etiology ; microbiology ; therapy ; Humans ; Infant ; Lung ; diagnostic imaging ; pathology ; Pleural Effusion ; etiology ; Pneumococcal Infections ; complications ; Radiography ; Retrospective Studies ; Serotyping ; Streptococcus pneumoniae ; classification ; isolation & purification

This study was performed to estimate the direct medical costs and epidemiology of pneumonia in adults of Korea. We conducted a multi-center, retrospective, observational study and collected data targeting for community-acquired pneumonia patients ( > or = 50 yr) from 11 hospitals. Costs attributable to the treatment of pneumonia were estimated by reviewing resource utilization and epidemiology data (distribution of pathogen, hospital length of stay, overall outcome) were also collected. A total 693 patients were included; average 70.1 ( +/- 10.5) aged, 57.3% male and average 1.16 CURB-65 (confusion, blood urea nitrogen, respiratory rate, blood pressure, age > 65 yr) scored. The pathogen was identified in the 32.9% (228 patients); Streptococcus pneumoniae accounted for 22.4% (51 patients) of identified pathogens. The hospital mortality was 3.2% (especially, for S. pneumoniae was 5.9%) and average length of stay was 9 days. The mean total cost for the treatment of pneumonia was US dollar (USD) 1,782 (SD: USD 1,501). Compared to the cost of all caused pneumonia, that of pneumococcal pneumonia was higher, USD 2,049 ( +/- USD 1,919), but not statistically significant. Charge of hospitalization accounted the greatest part of total medical costs. The economic burden of pneumonia was high in Korea, and the prevention of pneumonia should be considered as effective strategy.
Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Community-Acquired Infections/economics/*epidemiology/mortality ; Female ; *Health Care Costs ; Hospital Mortality ; Hospitalization ; Humans ; Length of Stay ; Male ; Middle Aged ; Pneumonia/economics/*epidemiology/microbiology ; Pneumonia, Pneumococcal/economics/epidemiology/microbiology ; Republic of Korea/epidemiology ; Retrospective Studies ; Severity of Illness Index ; Streptococcus pneumoniae/isolation & purification