Pneumococcal conjugate vaccine (PCV) introduction has reduced pneumococcal meningitis incidence. The Pneumococcal Serotype Replacement and Distribution Estimation (PSERENADE) project described the serotype distribution of remaining pneumococcal meningitis in countries using PCV10/13 for least 5–7 years with primary series uptake above 70%. The distribution was estimated using a multinomial Dirichlet regression model, stratified by PCV product and age. In PCV10-using sites (N = 8; cases = 1141), PCV10 types caused 5% of cases <5 years of age and 15% among ≥5 years; the top serotypes were 19A, 6C, and 3, together causing 42% of cases <5 years and 37% ≥5 years. In PCV13-using sites (N = 32; cases = 4503), PCV13 types caused 14% in <5 and 26% in ≥5 years; 4% and 13%, respectively, were serotype 3. Among the top serotypes are five (15BC, 8, 12F, 10A, and 22F) included in higher-valency PCVs under evaluation. Other top serotypes (24F, 23B, and 23A) are not in any known investigational product. In countries with mature vaccination programs, the proportion of pneumococcal meningitis caused by vaccine-in-use serotypes is lower (≤26% across all ages) than pre-PCV (≥70% in children). Higher-valency PCVs under evaluation target over half of remaining pneumococcal meningitis cases, but questions remain regarding generalizability to the African meningitis belt where additional data are needed.

Colistin (COL) is one of the few antimicrobials that retain activity against carbapenemase-producing Gram-negative bacteria (GNB). However, the emergence of COL resistance has renewed the use of combination therapy. The aim of this study was to determine the activity of COL plus rifampicin (RIF) against clinical isolates of COL-resistant, carbapenemase-producing GNB. We employed 36 COL-resistant carbapenemase-producing isolates (27 Klebsiella pneumoniae, 5 Serratia marcescens, and 4 Acinetobacter baumannii) belonging to 36 patients. E-test/agar dilution of all strains was performed with E-test strips of COL placed on agar plates with and without RIF. In 11 patients, the synergy was confirmed by time-kill studies. Synergy was detected in 34 isolates, whereas indifference was detected in two S. marcescens. The E-test/agar dilution method showed comparable results to the time-kill studies. Seven patients infected with these isolates (two meningitis, four sepsis, and one urinary tract infection) were treated with the combination successfully.

Mass spectrometry has revolutionized the clinical microbiology field in America’s and Europe’s industrialized countries, for being a fast, reliable and inexpensive technique. Our study is based on the comparison of the performance of two commercial platforms, Microflex LT (Bruker Daltonics, Bremen, Germany) and Vitek MS (bioMérieux, Marcy l´Etoile, France) for the identification of unusual and hard-to-diagnose microorganisms in a Reference Laboratory in Argentina. During a four-month period (February–May 2018) the diagnostic efficiency and the concordance between both systems were assessed, and the results were compared with the polyphasic taxonomic identification of all isolates. The study included 265 isolates: 77 Gram-Negative Bacilli, 33 Gram-Positive Cocci, 40 Anaerobes, 35 Actinomycetales, 19 Fastidious Microorganisms and 61 Gram-Positive Bacilli. All procedures were practiced according to the manufacturer’s recommendations in each case by duplicate, and strictly in parallel. Other relevant factors, such as the utility of the recommended extraction protocols, reagent stability and connectivity were also evaluated. Both systems correctly identified the majority of the isolates to species and complex level (82%, 217/265). Vitex MS achieved a higher number of correct species-level identifications between the gram-positive microorganisms; however, it presented greater difficulty in the identification of non-fermenting bacilli and a higher number of incorrect identifications when the profile of the microorganism was not represented in the commercial database. Both platforms showed an excellent performance on the identification of anaerobic bacteria and fastidious species. Both systems enabled the fast and reliable identification of most of the tested isolates and were shown to be very practical for the user.

Morbidity and mortality rates for pertussis in infants are high because disease often occurs before the onset of routine immunization or in those who do not complete a primary immunization series. Pertussis immunization is recommended during pregnancy to achieve antibody levels sufficient to protect young infants. To our knowledge, no previous reports of maternal pertussis immunization results in Latin America exist in the literature. This study compared pertussis antibody levels in newborns from mothers who received or did not receive a tetanus-diphtheria-acellular pertussis vaccination (TdapV) during pregnancy. Each mother's level of immunoglobulin G antibodies against pertussis toxin (IgG-PT) was measured with a validated, specific enzyme-linked immunosorbent assay (ELISA). Paired mother and cord serum samples were compared in 105 mothers with and 99 mothers without a TdapV. At birth, the mothers with and those without a TdapV had serum IgG-PT geometric mean concentrations (GMCs) of 35.1 and 9.8 ELISA units (EU)/mL, respectively (P < .0001); cord blood GMCs were 51.3 and 11.6 EU/mL, respectively (P < .0003); and cord blood IgG-PT levels were <5 EU/mL in 2.9% and 16.1% of the cord blood samples, respectively (P < .001). The mothers received their TdapV at a mean (± standard deviation [SD]) of 24.7 ± 4.8 weeks' gestation. Vaccination timing did not affect the IgG-PT GMC at birth. Placental antibody transference efficiencies (measured as the ratio of the cord blood GMC to the maternal GMC) were 1.46 and 1.18 for mothers with and those without a TdapV, respectively. The IgG-PT GMCs were 17.7 EU/mL in 36 infants in their first month of life and 11.6 EU/mL in 32 infants in their second month of life. Women who received a TdapV during pregnancy had significantly a higher serum/cord IgG-PT concentration at birth than mothers who did not receive a TdapV. Timing of the immunization was not correlated with antibody concentrations. Infants born to immunized mothers had significantly higher antibody levels during their first 2 months of life.