Pertussis is an acute, highly infectious respiratory disease caused by Bordetella pertussis, and is one of the leading causes of infant disease and death worldwide. The pertussis vaccine has been used in the expanded program on immunization globally since 1974 and the vaccination coverage remains high. In recent years, the pertussis incidence rate increased, even pertussis outbreaks occurred, in more and more countries or areas after years with low incidence level. The disease burden of pertussis has been seriously underestimated, and the prevention and control of pertussis is facing many challenges. This article reviews the epidemic status of pertussis worldwide, the factors affecting the reemergence of pertussis, and the challenges in the prevention and control to provide a reference for prevention and control of pertussis.
Infant ; Humans ; Whooping Cough/prevention & control* ; Vaccination ; Pertussis Vaccine/therapeutic use* ; Bordetella pertussis ; Disease Outbreaks

Aims: This study aims to produce Achromobacter biosurfactant in nutrient-rich and nutrient-limited media. Methodology and results: This study conducted fermentation on nutrient-rich and nutrient-limited media using a minimal salt medium (MSM). Dextrose and sodium citrate were used as sole carbon supplemented with 0.5% yeast extract for nutrient-rich media, while nutrient-limited media used molasses and rice straw hydrolysate (RSH) at variations of concentrations of 100 ppm and 200 ppm. The research was performed over 120 h and evaluated from growth response, surface tension and emulsification activity. The study revealed that the best surface tension value was when 2% (w/v) sodium citrate was used as C-source and 0.5% (w/v) yeast extract as N-source, after 72 h upon incubation at 30 °C/120 rpm having 45.45 ± 2.19 mN/m with emulsification activity 24.54 ± 3.42%. Whereas the best result of the nutrient-limited medium was obtained by RSH at a concentration of 200 ppm having 48.86 ± 5.36 mN/m. Conclusion, significance and impact of study The experiment showed that nutrient-limited medium from rice straw hydrolysate could compete with the nutrient-rich medium. The use of rice straw will contribute to the reduction of biosurfactant production costs and valorisation of agricultural waste.
Achromobacter denitrificans ; Surface-Active Agents

We previously demonstrated that Bordetella bronchiseptica (B. bronchiseptica) antigen (Ag) enhances the Mycoplasma hyopneumoniae Ag-specific immune response. The focus of this study was whether acellular bacterin of B. bronchiseptica could be used as an adjuvant to increase antigen-presenting capability of dendritic cells (DCs) by increasing the level of activation. The metabolic activity of DCs was increased by B. bronchiseptica, similar to lipopolysaccharide (LPS). Flow cytometry analysis revealed that B. bronchiseptica increases the expression of major histocompatibility complex class-2, cluster of differentiation (CD)40, CD54, and CD86 which are closely related to DC-mediated immune responses. B. bronchiseptica enhanced the production of cytokines related to adaptive immune responses. Furthermore, the survival rate of B. bronchiseptica-injected groups was 100% at 15 and 20 mg/kg doses, whereas that of LPS-injected groups was only 20%, 0% at 15 and 20 mg/kg doses respectively, and so B. bronchiseptica is likely to be safer than LPS. Taken together, these results indicate that B. bronchiseptica can be used as an adjuvant to enhance the antigen-presenting capability of DCs. B. bronchiseptica is a candidate for producing vaccines, especially in case of DC-mediating efficacy and safety demands. This study provides researchers and clinicians with valuable information regarding the usage of B. bronchiseptica as a safe bacteria-derived immunostimulating agent for developing efficient vaccines.
Bacterial Vaccines ; Bordetella bronchiseptica ; Bordetella ; Cytokines ; Dendritic Cells ; Flow Cytometry ; Immunization ; Major Histocompatibility Complex ; Mycoplasma hyopneumoniae ; Survival Rate ; Vaccines

OBJECTIVE: To study the value of cleaved lymphocytes in peripheral blood smear in assisting the early diagnosis of pertussis. METHODS: Nasopharyngeal swabs and peripheral blood samples were collected from 107 children with pertussis-like disease. PCR-flow fluorescent hybridization was used to detect the nucleic acids of Bordetella pertussis. Based on the detection results, the children were divided into two groups: pertussis (n=52) and non-pertussis (n=55). According to age, the pertussis group was divided into two subgroups: <1 year old (n=42) and ≥1 year old (n=10). According to disease severity, the pertussis group was divided into another two subgroups: mild (n=45) and severe (n=7). An automatic blood cell analyzer was used to determine peripheral blood cell counts. Wright's staining and peroxidase staining were used to observe and count cleaved lymphocytes under a microscope. RESULTS: Cleaved lymphocytes in peripheral blood were round with small cytoplast, less cytoplasm and cleaved or lobulated nuclei. According to the negative peroxidase staining results, these cells were confirmed as lymphocytes. Compared with the non-pertussis group, the pertussis group had significantly higher leukocyte count, lymphocyte percentage, platelet count, and percentage of cleaved lymphocytes (P<0.001). For the children with pertussis, the <1 year old subgroup had significantly higher lymphocyte percentage, platelet count, and percentage of cleaved lymphocytes than the ≥1 year old subgroup (P<0.05). The severe subgroup had slightly higher leukocyte count, lymphocyte percentage, platelet count, and percentage of cleaved lymphocytes than the mild subgroup (P>0.05). CONCLUSIONS The detection of cleaved lymphocytes combined with peripheral blood cell counts provides a new option for the early diagnosis of pertussis in children.
Bordetella pertussis ; Humans ; Infant ; Leukocyte Count ; Lymphocytes ; Platelet Count ; Whooping Cough

The Chinese and English names of pertussis or whooping cough show the important clinical features of the disease in terms of its course and cough characteristics respectively. In the clinical description of typical pertussis, the meanings of the Chinese and English words are not completely consistent, such as spastic cough versus paroxysmal cough, spasmodic stage/phase versus paroxysmal stage/phase, and "back-hook" versus whoop, and some descriptions in English are not seen in Chinese. This article aims to provide more comprehensive information for the understanding of pertussis by comparing the descriptions of typical clinical manifestations of pertussis in Chinese and English literatures and to put forward suggestions for the diagnosis of pertussis syndrome based on typical clinical manifestations.
Asian Continental Ancestry Group ; Bordetella pertussis ; Humans ; Language ; Whooping Cough

OBJECTIVE: To investigate the prevalence of Bordetella pertussis infection in children with chronic cough and its clinical features. METHODS: A total of 106 children who were treated at the outpatient service or hospitalized from January 1, 2016 to May 31, 2017 were enrolled. Their nasopharyngeal swabs and venous blood samples were collected for Bordetella pertussis culture, multiple PCR and serum anti-pertussis toxin antibody detection. According to these results, the children were divided into pertussis group with 26 children and control group with 80 children, and clinical features were analyzed for both groups. E-test stripes were used to determine the sensitivity of Bordetella pertussis strains to erythromycin, azithromycin, doxycycline, levofloxacin, sulfamethoxazole/trimethoprim and amoxicillin. RESULTS: Of the 106 children with chronic cough, 26 (24.5%) were found to have Bordetella pertussis infection. There were no significant differences in the incidence rates of typical symptoms of pertussis between the pertussis and control groups (P>0.05). E-test showed that erythromycin and azithromycin had a minimal inhibitory concentration (MIC) of >256 mg/L against five Bordetella pertussis strains, while amoxicillin had an MIC of 0.5-1 mg/L. CONCLUSIONS The presence of Bordetella pertussis infection in children with chronic cough should be taken seriously by clinicians, and children with chronic cough and Bordetella pertussis infection may not have the typical symptoms of pertussis and are mainly manifested as chronic cough. Amoxicillin may be an alternative drug for macrolide-resistant Bordetella pertussis infection.
Azithromycin ; Bordetella pertussis ; Child ; Humans ; Prevalence ; Whooping Cough ; epidemiology

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

PURPOSE: Although the DTaP and Tdap vaccines used to prevent pertussis have been used for a long time, there is no standard method for measuring pertussis antigens. Therefore, this preliminary study was conducted to develop an enzyme-linked immunosorbent assay method using an animal model for measuring antibodies against pertussis toxin, the most important pertussis pathogenic antigen, in the sera of vaccinated mice. MATERIALS AND METHODS: Bordetella pertussis Tohama phase I was cultured for 24–30 hours, and then pertussis toxin was purified from the culture medium by chromatography. Purified pertussis toxin was diluted in phosphate-buffered saline-coating buffer, and 100 µL of diluted pertussis toxin was added to each well and reacted at room temperature for 4 hours. Positive serum was diluted to 1/1,250–1/80,000 and negative serum was diluted to 1/50 to determine the coating concentration with the optimal signal/noise ratio. Optimal test conditions were confirmed from the dilution factors of the secondary antibody and streptavidin horseradish peroxidase (SA-HRP). RESULTS: Optimal conditions were as follows: 4 µg/mL for coating antigen; 1/40,000 for secondary antibody; and 1/1,000 for the SA-HRP dilution factor. Comparison of the sera obtained from mice treated with a developing vaccine and commercial vaccine with National Institute for Biological Standard and Control standard serum under the established conditions showed the following results: 1,300.62, 534.94, and 34.85, respectively. CONCLUSION: The method developed in this study is suitable for measuring anti-pertussis toxin antibodies and may be applicable for clinical sample analysis or indirect diagnosis of pertussis.
Animals ; Antibodies ; Bordetella pertussis ; Chromatography ; Diagnosis ; Enzyme-Linked Immunosorbent Assay* ; Horseradish Peroxidase ; Methods ; Mice* ; Models, Animal ; Pertussis Toxin ; Streptavidin ; Vaccines ; Whooping Cough

OBJECTIVE: To study the clinical features and risk factors of pertussis in children. METHODS: A retrospective analysis was performed for the clinical data and laboratory markers for immune function of 253 hospitalized children with pertussis. A total of 314 hospitalized children with cough were used as the control group. Quantitative real-time PCR was used to detect Bordetella pertussis DNA. The clinical data of both groups were collected to analyze the risk factors for pertussis. RESULTS: A total of 23 typical clinical parameters were compared between the pertussis and control groups, and there were significant differences in only 10 clinical parameters between the two groups (P<0.01). As for the complications observed in the two groups, the pertussis group had a significantly lower incidence rate of myocarditis than the control group (P<0.05). The pertussis group had significantly lower levels of serum globulin and IgM than the control group (P<0.05). Compared with the control group, the pertussis group had a significantly higher proportion of children with a lack of diphtheria-pertussis-tetanus immunization or timely immunization and a contact history of suspected pertussis patients (P<0.05). A lack of vaccine immunization or timely immunization and a contact history of suspected pertussis patients were risk factors for pertussis (P<0.05). CONCLUSIONS The clinical features are not typical in children with pertussis. Quantitative real-time PCR for detecting Bordetella pertussis DNA helps with the early diagnosis of atypical pertussis. Infants/toddlers should be immunized in time and be isolated from suspected pertussis patients to reduce the incidence of pertussis.
Bordetella pertussis ; Child ; Diphtheria-Tetanus-Pertussis Vaccine ; Humans ; Retrospective Studies ; Risk Factors ; Whooping Cough

Achromobacter xylosoxidans is a non-fermentative, aerobic, oxidase, and catalase-positive Gram-negative rod similar to Pseudomonas species. This organism colonizes aquatic environments and can cause nosocomial infections, especially in patients with immune deficiency such as human immunodeficiency virus infection, cancer, cystic fibrosis, neutropenia, and immunoglobulin M deficiency. Infections are found as bacteremia, pneumonia, meningitis, urinary tract infection, abscess formation, and osteomyelitis. It is known that most effective antibiotics are piperacillin/tazobactam, meropenem, and trimethoprim/sulfamethoxazol. But there is no optimal antibiotic therapy so far. We present a case of Achromobacter xylosoxidans bacteremia in a 13-month-old Korean girl who had past history of neutropenia.
Abscess ; Achromobacter denitrificans* ; Achromobacter* ; Anti-Bacterial Agents ; Bacteremia* ; Child* ; Colon ; Cross Infection ; Cystic Fibrosis ; Female ; HIV ; Humans ; Immunoglobulin M ; Infant ; Meningitis ; Neutropenia* ; Osteomyelitis ; Oxidoreductases ; Pneumonia ; Pseudomonas ; Urinary Tract Infections