PERISCOPE: road towards effective control of pertussis.

The resurgence and changing epidemiology of pertussis in high-income countries, the high infant mortality caused by pertussis in low-income countries, and the increasing morbidity in all age groups worldwide call for a concerted effort to both improve the current vaccines and develop new vaccines and vaccination strategies against pertussis. In this Personal View, we identify several key obstacles on the path to developing a durable solution for global control of pertussis. To systematically address these obstacles, the PERtussIS Correlates Of Protection Europe (PERISCOPE) Consortium was established in March, 2016. The objectives of this consortium are to increase scientific understanding of immunity to pertussis in humans induced by vaccines and infections, to identify biomarkers of protective immunity, and to generate technologies and infrastructure for the future development of improved pertussis vaccines. By working towards the accelerated licensure and implementation of novel, well tolerated, and effective pertussis vaccines, we hope to strengthen and stimulate further collaboration and transparency between the key stakeholders, including the public, the scientific community, public health institutes, regulatory authorities, and vaccine manufacturers.

Shattering a myth - Whooping cough susceptible to antibiotics.

Bordetella parapertussis is the causative agent of a milder form of pertussis or whooping cough. Little is reported about the antibiotic resistance patterns and mechanism of drug resistance of Bordetella parapertussis. The objective of this study has been to investigate antimicrobial resistance, distribution of integrons and presence of gene cassettes to quinolones (qnr) and sulfonamides (sul) among B. parapertussis strains' isolated from Pakistan. Thirty-five (35) samples were collected from various hospitals of Pakistan from children (median age 3 years) with pertussis-like symptoms, all were tested and confirmed to be B. Parapertussis. Resistance profile of Ampicillin, Cephalexin, Sulphamethoxazole, Chloramphenicol, Ofloxacin, Nalidixic acid, Gentamycin and Erythromycin were investigated through all samples. Majority of the isolates were found to be resistant to the afore-mentioned antibiotics except erythromycin. All isolates were resistant to quinolones phenotypically, but qnr genes were detected in only 25.7% (9/35) of isolates. On the other hand, 71.4% (25/35) isolates were resistant to sulfonamides phenotypically. From these 71% strains showing phenotypical resistance, 96% (24/25) were found to possess sul genes. Only two isolates were carrying class 1 integrons, which also harbored sul gene and qnr gene cassettes. It can be safely concluded that the phenotypic resistance patterns seemed mostly independent of presence of integrons. However, interestingly both integrons harboring strains were resistant to quinolones and sulfonamides and also possessed qnr and sul genes.

Quimioprofilaxis en coqueluche: ¿sacar agua a canastos? / Pertussis chemoprophylaxis: a sterile effort?

La quimioprofilaxis (QP) en coqueluche debe orientarse a proteger personas con riesgo de presentar complicaciones graves o fallecer: neonatos y lactantes bajo un año, senescentes, pacientes con afecciones cardiacas y pulmonares con insuficiencia funcional, y mujeres en tercer trimestre de embarazo (para proteger al neonato). La evidencia disponible permite recomendar una QP selectiva en los contactos ocurridos en el hogar, hasta 21 días de aparecer el caso primario, y antes de presentarse un caso secundario, recomendación que puede hacerse extensible a personas con alto riesgo que co-habitan con un caso índice en el hospital, guarderías infantiles y hogares de ancianos. La transmisibilidad de B. pertussis podría alcanzar una distancia mayor de 1,5 metros desde la cara del paciente, concepto importante para diseñar la QP en el medio hospitalario. Sólo existen argumentos sólidos para emplear macrólidos y azálidas; siete días es un plazo suficiente para erradicar B. pertussis con eritromicina o claritromicina, 5 días para azitromicina.

[Comparative pathomorphologic study of the toxic properties of a corpuscular pertussis vaccine and of a cell-free pertussis preparation]. / Sravnitel'noe patomorfologicheskoe izuchenie toksicheskikh svoistv korpuskuliarnoi kokliushnoi vaktsiny i beskletochnogo kokliushnogo preparata.

The comparative study of morphological changes in the body of outbred mice under the action of corpuscular pertussis vaccine and acellular pertussis preparation has been made. The corpuscular vaccine has been shown to produce a pronounced, dynamically increasing toxic effect, thus causing the damage of lymphoid thymic and spleen cells, prolonged interstitial reaction in the lungs, destructive inflammatory process at the site of injection. The acellular pertussis preparation is less toxic, induces less pronounced changes in these organs at the early period of the experiment, stimulates the proliferation of lymphoid cells and lymphoblast transformation. As noted in this study, the damaging action of pertussis vaccine is mainly indicated by pathological phenomena appearing in the organs of the immune system, pulmonary parenchyma and muscular tissue (in the inoculation zone).

Toxic and reactogenic properties of pertussis bacteria (experimental and clinical studies).

The results of the study revealed correlation between the reactogenicity of pertussis vaccines in epidemiological observations and the toxic properties of pertussis bacteria in experiment. Quantitative and qualitative differences were found between the toxic factors in pertussis bacteria depending on their type-specific serological activity. Serotype 1.0.3 microbes exhibit more pronounced toxicity which accounts for the greater reactogenicity of vaccines prepared from this serotype as compared with the preparation produced from the serotype 1.2.3. The obtained results suggest the necessity of considering the greater toxicity of the serotype 1.0.3 in the preparation of pertussis vaccines.

Use of glutamic acid to supplement fluid medium for cultivation of Bordetella pertussis.

The amino acid consumption by Bordetella pertussis growing in broth containing casein hydrolysate was examined. Serine, proline, alanine, glycine, aspartate, and glutamate were rapidly consumed, in a manner which suggested that they supplied the energy requirements of the organism; exhaustion of the energy source appeared to be the main factor limiting the yield of cells. There was no correlation between the utilization of individual amino acids and the phase of growth; uptake appeared to depend only upon relative concentrations. Consumption of threonine, phenylalanine, histidine, leucine, and methionine was slight; consumption of valine and lysine was variable, and isoleucine was excreted. The addition of monosodium l-glutamate (3 mg/ml) to the broth in shaken flasks increased the cell yield by an average of 43.5%. It had no detectable adverse effect upon the agglutin-producing capacity, agglutinability in antisera versus smooth and rough growth phases, mouse-lethal toxicity, histamine-sensitizing factor potency, or intracerebral protective potency of the culture. Broth supplemented with monosodium l-glutamate has been used over a 2-year period to prepare experimental vaccines by both batch and continuous cultivation methods at controlled pH; the cell yields obtained from the supplemented broth have been up to 52% higher than those from the basal broth. The use of glutamate to replace a proportion of casein hydrolysate in the broth caused a reduction in the cell yield, an alteration in cell morphology, and reduction in the mouse-lethal toxicity, the histamine-sensitizing factor potency, and the intracerebral protective potency of the cells.