OBJECTIVE: To investigate the alternative antimicrobial drugs for the treatment of neonatal pertussis and the antigen genotypes of Bordetella pertussis (B. pertussis) strains. METHODS: A total of 32 B. pertussis strains isolated from neonates between May 2013 and July 2018 were used in this study. E-test stripes were used to measure the minimal inhibitory concentration (MIC) of 18 antimicrobial drugs including erythromycin, sulfamethoxazole-trimethoprim (SMZ) and ampicillin. The 23S rRNA gene of isolated strains was amplified and sequenced to identify the mutation site of erythromycin resistance gene, and the seven antigen genotypes of B. pertussis strains (ptxA, ptxC, ptxP, prn, fim2, fim3 and tcfA2) were analyzed. RESULTS: Of the 32 B. pertussis strains, 25 (78%) were resistant to erythromycin, azithromycin, clarithromycin and clindamycin, with an MIC of >256 mg/L, and A2047G mutation was observed in the 23S rRNA gene. All strains had an MIC of ≤0.064 mg/L for SMZ. The MIC of ampicillin, amoxicillin, amoxicillin-clavulanic acid and ceftriaxone ranged from 0.032 to 1 mg/L. The strains resistant to macrolide antibiotics had an antigen genotype of ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3-1/tcfA2. CONCLUSIONS B. pertussis strains from neonates are often resistant to macrolides, and the in vitro test shows that off-label use of sulfonamides is a reliable regimen for the treatment of neonates with macrolide-resistant pertussis. The prevalence of drug-resistant strains further emphasizes the importance of immunoprophylaxis.
Anti-Bacterial Agents ; Bordetella pertussis ; genetics ; Erythromycin ; Genotype ; Humans ; Infant, Newborn ; Microbial Sensitivity Tests ; Whooping Cough

Pertussis is a representative vaccine-preventable disease. However, there have been recent outbreaks in countries where even higher vaccination against the disease. One reason is the emergence of antigenic variants, which are different to vaccine type. In Korea, reported cases have rapidly increased since 2009. Therefore, we analyzed genotype of strains isolated in 2011-2012 by multilocus sequence typing method. As expected, the genotype profiles of tested genes dramatically changed. The major sequence type changed from ST1 to ST2, and new sequence type (ST8) appeared. In the minimum spanning tree, recent isolates belonging to the ACC-I-ST3 subgroup were detected that were composed of ST2, ST3, and ST6. In particular, the ST2 frequency increased to 81%. The novel ST8 was linked to the increased frequency of ST2. In addition, toxic strains carrying the ptxP3 promoter type were confirmed. This ptxP3 type emerged from 2009 and its frequency had increased to 100% in 2012. Based on these results, it can be inferred that the genotypic changes in the currently circulating strains are strongly associated with the recent increasing of pertussis in Korea. Therefore, the surveillance system should be strengthened, and genetic characterization of the isolates should be expanded to the whole genome sequence level.
*Antigenic Variation ; Antigens/*genetics/immunology/metabolism ; Bacterial Proteins/genetics/metabolism ; Bordetella pertussis/*genetics/isolation & purification/*metabolism ; Genes, Bacterial ; Genotype ; Humans ; Pertussis Toxin/genetics/metabolism ; Promoter Regions, Genetic ; Republic of Korea ; Sequence Analysis, DNA ; Whooping Cough/immunology/*microbiology/pathology

A recent resurgence of pertussis has raised public health concerns even in developed countries with high vaccination coverage. The aim of this study was to describe the clinical characteristics of infant pertussis, and to determine the relative importance of household transmission in Korea. The multicenter study was prospectively conducted from January 2009 to September 2011. We identified the demographic and clinical data from these patients and performed the diagnostic tests for pertussis in their household contacts. Twenty-one patients with confirmed pertussis were included in the analysis. All infections occurred in infants younger than 6 months of age (mean age, 2.5 months) who had not completed the primary DTaP vaccination except for one patient. Infants without immunization history had a significant higher lymphocytosis and longer duration of hospital stay compared to those with immunization. All were diagnosed with PCR (100%), however, culture tests showed the lowest sensitivity (42.9%). Presumed source of infection in household contacts was documented in 85.7%, mainly parents (52.6%). Pertussis had a major morbidity in young infants who were not fully immunized. Household members were responsible for pertussis transmission of infants in whom a source could be identified. The control of pertussis through booster vaccination with Tdap in family who is taking care of young infants is necessary in Korea.
Bordetella pertussis/genetics ; Diphtheria-Tetanus-acellular Pertussis Vaccines/immunology ; Female ; Humans ; Immunization, Secondary ; Infant ; Length of Stay ; Lymphocytosis/etiology ; Male ; Parents ; Polymerase Chain Reaction ; Prospective Studies ; Republic of Korea ; Whooping Cough/diagnosis/immunology/*transmission

The role of atypical bacteria and the effect of antibiotic treatments in acute bronchitis are still not clear. This study was conducted at 22 hospitals (17 primary care clinics and 5 university hospitals) in Korea. Outpatients (aged > or = 18 yr) who had an acute illness with a new cough and sputum (< or = 30 days) were enrolled in 2013. Multiplex real-time polymerase chain reaction (RT-PCR) was used to detect five atypical bacteria. A total of 435 patients were diagnosed as having acute bronchitis (vs. probable pneumonia, n = 75), and 1.8% (n = 8) were positive for atypical pathogens (Bordetella pertussis, n = 3; B. parapertussis, n = 0; Mycoplasma pneumoniae, n = 1; Chlamydophila pneumoniae, n = 3; Legionella pneumophila, n = 1). Among clinical symptoms and signs, only post-tussive vomiting was more frequent in patients with atypical pathogens than those without (P = 0.024). In all, 72.2% of the enrolled patients received antibiotic treatment at their first visits, and beta-lactams (29.4%) and quinolones (20.5%) were the most commonly prescribed agents. In conclusion, our study demonstrates that the incidence of atypical pathogens is low in patients with acute bronchitis, and the rate of antibiotic prescriptions is high.
Anti-Bacterial Agents/therapeutic use ; Bordetella parapertussis/genetics/*isolation & purification ; Bordetella pertussis/genetics/*isolation & purification ; Bronchitis/drug therapy/*microbiology ; Chlamydophila pneumoniae/genetics/*isolation & purification ; Community-Acquired Infections/microbiology ; Female ; Humans ; Hypertension/complications ; Legionella pneumophila/genetics/*isolation & purification ; Male ; Middle Aged ; Mycoplasma pneumoniae/genetics/*isolation & purification ; Real-Time Polymerase Chain Reaction ; Republic of Korea ; Sputum/microbiology

Epidemiological data of Bordetella pertussis infection among adolescents and adults are limited in Korea. Patients (> or = 11 yr of age) with a bothersome cough for less than 30 days were enrolled during a 1-yr period at 22 hospitals in Korea. Nasopharyngeal swabs were collected for polymerase chain reaction (PCR) and for bacteriologic culture. In total, 490 patients were finally enrolled, and 34 (6.9%) patients tested positive for B. pertussis; cough duration (14.0 days [7.0-21.0 days]) and age distribution were diverse. The incidence was the highest in secondary referral hospitals, compared to primary care clinics or tertiary referral hospitals (24/226 [10.6%] vs. 3/88 [3.4%] vs. 7/176 [4.0%], P = 0.012), and the peak incidence was observed in February and August (15.8% and 15.9%), with no confirmed cases between March and June. In the multivariate analysis, post-tussive vomiting was significantly associated with pertussis (odds ratio, 2.508; 95% confidence interval, 1.146-5.486) and secondary referral hospital showed a borderline significance. In conclusion, using a PCR-based method, 6.9% of adolescent and adult patients with an acute cough illness had pertussis infection in an outpatient setting. However, hospital levels and seasonal trends must be taken into account to develop a better strategy for controlling pertussis.
Adolescent ; Adult ; Bordetella pertussis/*genetics ; Child ; DNA, Bacterial/*analysis ; Demography ; Female ; Humans ; Incidence ; Male ; Middle Aged ; Multivariate Analysis ; Odds Ratio ; *Polymerase Chain Reaction ; Republic of Korea/epidemiology ; Seasons ; Vomiting/etiology ; Whooping Cough/*epidemiology/microbiology/pathology ; Young Adult

This study focused on prevention and treatment of acute and chronic asthma by oligonucleotides containing unmethylated CpG motifs (CpG-ODNs). Acute and chronic asthma models of mice were made by sensitizing and inhaling ovalbumin (OVA); The number of white blood cells (WBC) and eosnophils (EOS) in bronchoalveolar lavage fluid (BALF) was counted and the concentration of cytokines and vascular endothelial growth factor (VEGF) was examined in BALF by ELISA kit. After that, TLR-9 mRNA was detected in mice spleen cells by reverse transcription polymerase chain reaction (RT-PCR) and TLR-9 protein was determined in mice lung tissues by Western blotting. Compared with acute asthma models of mice, WBC in BALF decreased obviously in the groups of Bordetella pertussis, CpG-ODNs and seq A to seq I which were administrated by both of intragastric (ig) and intraperitoneal (ip) injection group, EOS decreased obviously in Bordetella pertussis, CpG+ and seq A to seq D ig groups, and in all ip administrating groups, although it was not effective in the groups of seq E to seq I. In chronic asthma models of mice, IFN-gamma increased ((1) control: 176.45 +/- 23.46 pg x mL(-1); (2) model: 174.11 +/- 22.71 pg x mL(-1); (3) CpG+ ip: 220.56 +/- 15.42 pg x mL(-1); (4) seq A ip: 225.23 +/- 21.60 pg x mL(-1)) and IL-4 decreased obviously (1) control: 66.91 +/- 5.81 pg x mL(-1); (2) model: 81.02 +/- 11.24 pg x mL(-1); (3) CpG+ ip: 63.99 +/- 6.09 pg x mL(-1); (4) seq A ip: 62.75 +/- 10.03 pg x mL(-1)) in the BALF of CpG+ and seq A ip group, although VEGF was not changed in this research. And also, TLR-9 mRNA in spleen cells (TLR-9/GAPDH: (1) control: 0.62 +/- 0.13; (2) model: 0.66 +/- 0.17; (3) CpG+ ip: 1.46 +/- 0.26; (4) seq A ip: 1.42 +/- 0.34) and TLR-9 protein in lung tissues (TLR-9/beta-actin: (1) control: 0.63 +/- 0.16; (2) model: 0.61 +/- 0.07; (3) CpG+ ip: 1.15 +/- 0.25; (4) seq A ip: 1.03 +/- 0.29) both increased in ip groups, but the change was not significant in ig group. The study confirms that CpG-ODNs and seq A could inhibit airway inflammation remarkably, this mechanism might be related with regulating Th1/Th2 balance and controlling the expression of TLR-9.
Adjuvants, Immunologic ; isolation & purification ; pharmacology ; Animals ; Asthma ; chemically induced ; metabolism ; pathology ; Bordetella pertussis ; Bronchoalveolar Lavage Fluid ; Eosinophils ; drug effects ; Female ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Leukocyte Count ; Leukocytes ; drug effects ; Lung ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Inbred ICR ; Oligodeoxyribonucleotides ; isolation & purification ; pharmacology ; Ovalbumin ; RNA, Messenger ; metabolism ; Random Allocation ; Signal Transduction ; drug effects ; Spleen ; metabolism ; Th1-Th2 Balance ; Toll-Like Receptor 9 ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism