Differential Ubiquitination as an Effective Strategy Employed by the Blood-Brain Barrier for Prevention of Bacterial Transcytosis.

The protective mechanisms of blood-brain barrier (BBB) prohibiting entry of pathogens into central nervous system (CNS) are critical for maintenance of brain homeostasis. These include various intracellular defense mechanisms that are vital to block transcytosis of neurotropic pathogens into the CNS. However, mechanistic details of coordination between these defense pathways remain unexplored. In this study, we established that BBB-driven ubiquitination acts as a major intracellular defense mechanism for clearance of Streptococcus pneumoniae, a critical neurotropic pathogen, during transit through BBB. Our findings suggest that the BBB employs differential ubiquitination with either K48- or K63-ubiquitin (Ub) chain topologies as an effective strategy to target S. pneumoniae toward diverse killing pathways. While K63-Ub decoration triggers autophagic killing, K48-Ub directs S. pneumoniae exclusively toward proteasomes. Time-lapse fluorescence imaging involving proteasomal marker LMP2 revealed that in the BBB, the majority of the ubiquitinated S. pneumoniae was cleared by proteasome. Fittingly, inhibition of proteasome and autophagy pathway led to accumulation of K48-Ub- and K63-Ub-marked S. pneumoniae, respectively, and triggered significant increases in intracellular S. pneumoniae burden. Moreover, genetic impairment of either K48- or K63-Ub chain formation demonstrated that although both chain types are key in disposal of intracellular S. pneumoniae, K48-Ub chains and subsequent proteasomal degradation have more pronounced contributions to intracellular S. pneumoniae killing in the BBB. Collectively, these observations, for the first time, illustrated a pivotal role of differential ubiquitination deployed by BBB in orchestrating a symphony of intracellular defense mechanisms for interception and degradation of S. pneumoniae, blocking its entry into the brain, which could be exploited to prevent bacterial CNS infections. IMPORTANCE The blood-brain barrier (BBB) represents a unique cellular barrier that provides structural integrity and protection to the CNS from pathogen invasion. Recently, ubiquitination, which is key for cellular homeostasis, was shown to be involved in pathogen clearance. In this study, we deciphered that the BBB deploys differential ubiquitination as an effective strategy to prevent S. pneumoniae trafficking into the brain. The different ubiquitin chain topologies formed on S. pneumoniae dictated the selection of downstream degradative pathways, namely, autophagy and proteasomes, among which the contribution of the proteasomal system in S. pneumoniae killing is more pronounced. Overall our study revealed how the BBB deploys differential ubiquitination as a strategy for synchronization of various intracellular defense pathways, which work in tandem to ensure the brain's identity as an immunologically privileged site.

Adolescente con corea de inicio agudo: a propósito de una entidad olvidada / Adolescent with acute-onset chorea: on the subject of a forgotten entity

La corea de Sydenham es como se denomina el cuadro de origen neurológico consistente en agitación y movimientos anormales que ocurre en contexto de una fiebre reumática, secundariamente a la infección por estreptococo del grupo A. Dado que la incidencia de fiebre reumática ha disminuido significativamente en los últimos años, las complicaciones asociadas pueden considerarse actualmente excepcionales. No obstante, dado que presenta un pronóstico excelente si se instaura precozmente el tratamiento, es muy importante saber reconocer el cuadro clínico (AU)

Sydenham’s chorea, with a documented relationship with group A streptococcal infections, is the one of the most common acquired movement disorder of adolescence. However, rheumatic fever´s incidence is significantly lower than years ago. The clinical picture is very characteristic, and its recognition is essential in order to improve the prognostic starting an specific treatment as soon as possible (AU)

Experimental Study on the Resistance of Synthetic Penicillin Solid Lipid Nanoparticles to Clinically Resistant Staphylococcus aureus.

BACKGROUND: With the increasing resistance of antibiotics to bacteria, new and effective methods are needed to transform existing antibiotics to solve the problem of long development cycles for new drugs. The antibiotic nanodelivery system has proven to be a promising strategy. AIM: The purpose of this study is to synthesize penicillin solid lipid nanoparticles (penicillin SLNs) to enhance the antibacterial activity of penicillin against drug-resistant Staphylococcus aureus. MATERIALS AND METHODS: Penicillin SLNs were synthesized. And particle size, the polydispersity index (PI), and zeta potential (ZP) of penicillin SLNs were measured. The surface morphology of penicillin SLNs was observed using a transmission electron microscope. RESULTS: The particle size of penicillin SLNs is 112.3 ± 11.9 nm, the polydispersity index (PI) and zeta potential (ZP) of penicillin SLNs are 0.212 ± 0.03 and -27.6 ± 5.5 mV. The encapsulation efficiency and drug loading were 98.31 ± 1.2% and 4.98 ± 0.05 (%w/w), respectively. Penicillin SLNs had a more significant inhibitory effect on the growth of methicillin-sensitive Staphylococcus aureus (MSSA) after the drug and the bacteria were incubated for 12 hours. The number of MRSA colonies in the penicillin group increased after 12 hours, while the number of MRSA colonies in the penicillin SLNs group did not change significantly. CONCLUSION: Penicillin SLNs enhance the ability of penicillin to enter cells and increase the concentration of penicillin in the cell and also extend the residence time of penicillin in the cell. Our findings indicated that penicillin SLNs enhance the inhibitory effect of penicillin on drug-resistant Staphylococcus aureus.

Rheumatic heart disease in The Gambia: clinical and valvular aspects at presentation and evolution under penicillin prophylaxis.

BACKGROUND: Rheumatic heart disease (RHD) remains the leading cause of cardiac-related deaths and disability in children and young adults worldwide. In The Gambia, the RHD burden is thought to be high although no data are available and no control programme is yet implemented. We conducted a pilot study to generate baseline data on the clinical and valvular characteristics of RHD patients at first presentation, adherence to penicillin prophylaxis and the evolution of lesions over time. METHODS: All patients registered with acute rheumatic fever (ARF) or RHD at two Gambian referral hospitals were invited for a clinical review that included echocardiography. In addition, patients were interviewed about potential risk factors, disease history, and treatment adherence. All clinical and echocardiography information at first presentation and during follow-up was retrieved from medical records. RESULTS: Among 255 registered RHD patients, 35 had died, 127 were examined, and 111 confirmed RHD patients were enrolled, 64% of them females. The case fatality rate in 2017 was estimated at 19.6%. At first presentation, median age was 13 years (IQR [9; 18]), 57% patients had late stage heart failure, and 84.1% a pathological heart murmur. Although 53.2% of them reported history of recurrent sore throat, only 32.2% of them had sought medical treatment. A history suggestive of ARF was reported by 48.7% patients out of whom only 15.8% were adequately treated. Two third of the patients (65.5%) to whom it was prescribed were fully adherent to penicillin prophylaxis. Progressive worsening and repeated hospitalisation was experienced by 46.8% of the patients. 17 patients had cardiac surgery, but they represented only 18.1% of the 94 patients estimated eligible for cardiac surgery. CONCLUSION: This study highlights for the first time in The Gambia the devastating consequences of RHD on the health of adolescents and young adults. Our findings suggest a high burden of disease that remains largely undetected and without appropriate secondary prophylaxis. There is a need for the urgent implementation of an effective national RHD control programto decrease the unacceptably high mortality rate, improve case detection and management, and increase community awareness of this disease.

Antimicrobial use on 74 Japanese pig farms in 2019: A comparison of Japanese and European defined daily doses in the field.

Defined daily doses (DDD) have been established in human medicine to standardize the measurement of treatment in a population. In veterinary medicine, the European Medicine Agency published defined daily dose (DDDvet) values for antimicrobial agents used in food-producing animals in 2016. National defined doses (DDDjp) for antimicrobials used for pigs in Japan have recently been determined. The aim of this study was to compare the results of calculated antimicrobial use in the field using the DDDjp and DDDvet values. Data from 74 pig farms in Japan relative to antimicrobial use in 2019 was collected. The numbers of DDDs (the weight of biomass treated in kg-days) using DDDjp and DDDvet values for each farm and for different antimicrobial classes were compared. Associations between calculated numbers of DDDjp and DDDvet on farm level were investigated. In addition, differences in antimicrobial use were investigated between different production types of farms (farrowing, finishing and farrow-to-finish farms). Using DDDjp and DDDvet values, the aggregated number of DDDs for 74 farms were 4,099,188 and 2,217,085 respectively, with the former being larger by 1.85 times than the latter. The most frequently used antimicrobial class was penicillin regardless of whether DDDjp or DDDvet was used. The absence of DDDvet values for certain antimicrobial agents used in Japan and the differences in the number of DDDjps/PCU and DDDvets/PCU indicated the need for Japanese DDDs. The number of DDDs per kg population correction unit (PCU) per farm tended to be higher in farrowing farms than in farrow-to-finish farms and finishing farms, with no significant difference (P = 0.19).

Inverse association between use of broad spectrum penicllin with beta-lactamase inhibitors and prevalence of type 1 diabetes mellitus in Europe.

Increasing incidence of type 1 diabetes is supposed to be induced by environmental factors. Microbiome modulated by antibiotics seems to serve as one of the environmental factors which could influence the development of T1DM. Mitochondria, as autochthonous environmental bacteria living in our cells, and other bacteria share many common enzymes including beta-lactamases and it is supported by evidence that some beta-lactamase inhibitors are able to interact with counterpart enzymes. Thus, antibiotics may utilize two different pathways influencing the development of T1DM; one through modulation of microbiome and a second one via the interaction of mitochondrial enzymes. Data of consumption of penicillin (both narrow and broad spectrum) and beta-lactamase inhibitors in 30 European countries were collected from the database of the European Centre for Disease Prevention and Control. These data were correlated with the prevalence reported by the International Diabetes Federation (2019) referring to type 1 diabetes in Europe. No correlation was found between total penicillin consumption or use of broad spectrum penicillin and the prevalence of type 1 diabetes. Nevertheless, broad spectrum penicillin, in combination with beta-lactamase inhibitor, was in inverse correlation with the prevalence of type 1 diabetes (r = - 0.573, p = 0.001). On the other hand, narrow spectrum penicillin was in positive correlation with type 1 diabetes (r = 0.523, p = 0.003). Prevalence of type 1 diabetes showed an inverse correlation with the use of beta-lactamase inhibitors and a positive one with that of narrow spectrum penicillin. Such a detailed analysis has not so far been provided referring to the penicillin group. In the background of this association either microbiomal or direct mitochondrial effects can be supposed.

Antistaphylococcal penicillins vs. cefazolin in the treatment of methicillin-susceptible Staphylococcus aureus infective endocarditis: a quasi-experimental monocentre study.

Whether cefazolin is as effective and safer than antistaphylococcal penicillins (ASPs) for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) is still debated in the absence of a randomized controlled trial. In this quasi-experimental study, we aimed to assess the effectiveness and safety of these two treatments in MSSA-IE, using the ASPs nationwide shortage in April 2016 as a unique opportunity to overcome the indication bias associated with observational studies. In this single-centre study, we compared patients with Duke-Li definite MSSA-IE treated with ASPs from January 2015 to March 2016 versus those treated with cefazolin from April 2016 to December 2018, when ASPs were not available. Effectiveness outcome was 90-day all-cause mortality. Safety outcomes included significant decrease in GFR and significant increase in serum liver enzymes. Logrank test was used to compare survival rates. Of 73 patients with MSSA-IE, 35 and 38 were treated with ASPs and cefazolin, respectively. Baseline patients' characteristics (demography, native or prosthetic valve IE, clinical characteristics, cardiac and septic complications) were similar between groups. Ninety-day all-cause mortality was 28.6% and 21.1%, in patients treated with ASPs and cefazolin, respectively (logrank p = 0.5727). There was no difference between groups for incident renal or liver toxicity events: acute kidney injury 45.7% vs. 44.7% (p = 0.933), increased ALT 5.7% vs. 13.2% (p = 0.432), bilirubin increase 5.7% vs. 10.5% (p = 0.676), in ASPs vs. cefazolin groups, respectively. In this quasi-experimental, effectiveness and safety did not statistically differ between ASPs and cefazolin for MSSA-IE treatment.

Impending Aortic Rupture in a Patient with Syphilitic Aortitis.

We report the case of a 48-year-old man, admitted for atrial fibrillation with rapid heart rate and intense chest pain. A quick evaluation revealed a giant aortic aneurysm with severe aortic regurgitation and pericardial fluid without a trace of aortic dissection. Because of high suspicion of aortic rupture, an emergency surgery was planned, and a Bentall procedure was performed. On examination of the aortic wall revealing vertical wrinkling with a tree bark aspect, suspicion of syphilitic aortitis arose. The diagnosis was confirmed through postoperative serologic testing and histological examination. Histopathologic differential diagnosis, special treatment and follow-up are presented.

Distinct contribution of hyperbaric oxygen therapy to human neutrophil function and antibiotic efficacy against Staphylococcus aureus.

Staphylococcus aureus (SA) causes superficial and severe endovascular infections. The present in vitro study investigates the anti-SA mechanisms of hyperbaric oxygen therapy (HBOT) on direct bacterial killing, antibiotic potentiation, and polymorphonuclear leukocyte (PMN) enhancement. SA was exposed to isolated human PMNs, tobramycin, ciprofloxacin, or benzylpenicillin. HBOT was used as one 90-min session. Bacterial survival was evaluated after 4 h by quantitative bacteriology. PMN functionality as reactive oxygen species (ROS) production was measured by means of dihydrorhodamine 123 analysis. We showed that HBOT exhibits significant direct anti-SA effects. HBOT increased the anti-SA effects of PMNs by 18% after PMA stimulation (p = 0.0004) and by 15% in response to SA (p = 0.36). HBOT showed an additive effect as growth reductions of 26% to sub-MICs of tobramycin (p = 0.0057), 44% to sub-MICs of ciprofloxacin (p = 0.0001), and 26% to sub-MICs of penicillin (p = 0.038). The present in vitro study provides evidence that HBOT has differential mechanisms mediating its anti-SA effects. Our observation supports the clinical possibility for adjunctive HBOT to augment the host immune response and optimize the efficacy of antibiotic treatments.

Extracellular vesicles from dHL-60 cells as delivery vehicles for diverse therapeutics.

Extracellular vesicles (EVs) are membrane-derived heterogeneous vesicles that mediate intercellular communications. They have recently been considered as ideal vehicles for drug-delivery systems, and immune cells are suggested as a potential source for drug-loaded EVs. In this study, we investigated the possibility of neutrophils as a source for drug-loaded EVs. Neutrophil-like differentiated human promyelocytic leukemia cells (dHL-60) produced massive amounts of EVs within 1 h. The dHL-60 cells are also easily loaded with various cargoes such as antibiotics (penicillin), anticancer drug (paclitaxel), chemoattractant (MCP-1), miRNA, and Cas9. The EVs derived from the dHL-60 cells showed efficient incorporation of these cargoes and significant effector functions, such as bactericidal activity, monocyte chemotaxis, and macrophage polarization. Our results suggest that neutrophils or neutrophil-like promyelocytic cells could be an attractive source for drug-delivery EVs.

Safety and efficacy of direct two-step penicillin challenges with an inpatient pharmacist-driven allergy evaluation.

Background: Penicillin allergy is commonly reported and has clinical and financial consequences for patients and hospitals. A penicillin evaluation program can safely delabel patients and optimize antibiotic therapy. Pharmacists who perform this task have focused on a detailed interview or penicillin skin testing (PST). Antibiotic graded challenge after PST requires more resources and is more costly than going directly to a two-step challenge. Objective: To determine whether a pharmacist-driven penicillin allergy evaluation and a testing protocol that primarily uses direct oral challenges can safely delabel patients. Methods: Adult patients (ages >18 years) with a penicillin allergy in their electronic medical record (EMR) who were admitted between September 2019 and June 2020 were eligible. Although all patients with penicillin allergy were eligible, priority was given to patients who required antibiotics. Patients were interviewed, and, if indicated, based on an institutional protocol, were tested by using PST and/or two-step oral challenge. If the patient passed the challenge, then the penicillin allergy label was removed in the EMR and the patient counseled. Demographic information, allergy questionnaire results, testing results, and changes in antimicrobial therapy were collected. Results: Fifty patients were evaluated from September 2019 to June 2020. Ninety-six percent of the patients were delabeled, and antibiotic therapy changed for 54%. Twenty patients were delabeled with an interview alone, and 30 patients underwent oral two-step challenge. Only one patient required PST. Conclusion: A pharmacist-driven penicillin allergy evaluation program focused on direct oral graded challenges and bypassing PST can effectively delabel admitted patients. However, more safety data are needed before implementation of similar programs to optimize antibiotic treatment.

Evolución de la distribución de serotipos de Streptococcus pneumoniae aislados en líquido pleural en la Comunidad de Madrid entre los años 2007 y 2018 / Evolution of the distribution of Streptococcus pneumoniae serotypes isolated in pleural fluid in the Madrid Autonomous Community between the years 2007-2018

INTRODUCCIÓN: El objetivo de este estudio es describir la distribución de serotipos de Streptococcus pneumoniae aislados de líquido pleural en la Comunidad de Madrid entre los años 2007 y 2018. MÉTODOS: Se estudiaron las cepas de episodios de enfermedad neumocócica invasiva aisladas en la Comunidad de Madrid durante el periodo 2007-2018. La frecuencia de serotipos en líquido pleural se comparó con la observada en otras muestras. RESULTADOS: Se procesaron 6.115 cepas invasivas de neumococo; de ellas, 182(3%) se aislaron en muestras de líquido pleural. El 70,9% de los aislados pertenecía a alguno de los 6 siguientes serotipos: 1, 3, 19A, 8, 7F y 5. Los serotipos 3 y 8 aumentaron de manera significativa: pasaron del 9,6 al 30,8%, y del 5,3% al 20,5%, respectivamente, entre los periodos 2007-2010 y 2015-2018. CONCLUSIÓN: Los serotipos 3 y 8 son causas importantes de infección del líquido pleural en nuestra área en la actualidad

INTRODUCTION: The aim of this study was to describe the distribution of Streptococcus pneumoniae serotypes in isolates from pleural fluid in the Madrid Autonomous Community between the years 2007-2018. METHODS: Invasive pneumococcal disease strains isolated during the period 2007-2018 were studied. The frequency of serotypes from pleural fluid was compared with that observed in other samples. RESULTS: A total of 6,115 pneumococcal invasive isolates were processed. Of them, 182 (3%) were isolated from pleural fluid. A total of 70.9% of isolates belonged to some of the following 6 serotypes: 1, 3, 19A, 8, 7F and 5. The serotypes 3 and 8 increased significantly from 9.6% to 30.8%, and from 5.3% to 20.5%, respectively, over the periods 2007-2010 to 2015-2018. CONCLUSIONS: Pneumococcal serotypes 3 and 8 are currently significant causes of infection of pleural fluid in our region

Bilateral exudative retinal detachment in undiagnosed ocular syphilis after treatment with corticosteroids.

A case of a young Caucasian male who presented bilateral papilledema is described. He was misdiagnosed with bilateral anterior optic neuritis, developing panuveitis and exudative bilateral retinal detachment after being treated with megadoses of corticosteroids. He was finally diagnosed with ocular syphilis and treated with intravenous aqueous crystalline penicillin for 14 days, with complete resolution of his symptoms.

An observational cohort study on antimicrobial usage on dairy farms in Quebec, Canada.

Quantification of antimicrobial usage (AMU) is crucial to measure the effect of intervention programs, to determine associations between usage and resistance, to compare populations, and for benchmarking purposes. The primary objective of the study was to describe quantitatively the AMU on Quebec dairy farms over 1 yr: (1) the total AMU, (2) the AMU per administration route (intramammary, injectable, oral, intrauterine), and (3) the AMU per antimicrobial class and according to the categorizations of Health Canada and the World Health Organization. The secondary objective was to assess the effect of several characteristics (herd size, level of milk production, and incidence rate of common infectious diseases) on AMU rate. The AMU data were obtained for 101 dairy farms randomly selected in 3 important Quebec dairy regions by collecting and recording all empty drug packaging and invoices for medicated feed (spring 2017 to spring 2018). The AMU rate was reported in number of Canadian defined course doses for cattle per 100 cow-years. The average herd size was 67 cows per farm, and 2/101 farms were certified organic. Overall, an estimated mean of 537 Canadian defined course doses for cattle/100 cow-years was observed. The intramammary route during lactation was the most frequently observed, followed, in decreasing order of usage, by oral route in the feed, intramammary route at drying-off, and injectable route. Oral (other than in animal feed) and intrauterine formulations were infrequently collected from the garbage cans. The 5 most frequently observed antimicrobial classes were, by decreasing order of usage, ionophores, penicillins, aminocoumarins, aminoglycosides, and polymyxins. Highest priority critically important antimicrobials as defined by the World Health Organization were mainly collected from intramammary formulations during lactation followed by injectable and drying-off intramammary formulations. The herd size was positively associated with the total AMU rate but not with the usage rate of highest priority critically important antimicrobials. Incidence of diseases along with preventive use of antimicrobials (drying-off and medicated feed with antimicrobials) explained 48% of the variance in total AMU rate.

Rectal cancer mimic: a rare case of syphilitic proctitis.

Syphilitic proctitis is a rare presentation of sexually transmitted infection that poses a diagnostic challenge as it mimics rectal cancer clinically, radiologically and endoscopically. We report a case of a 66-year-old male patient with a background of HIV infection presenting with obstructive bowel symptoms and initial diagnosis of rectal cancer on CT. Sigmoidoscopy and histopathology were non-diagnostic. A diagnosis of secondary syphilis was suspected after obtaining sexual history and diagnostic serology, avoiding planned surgical intervention.

Sífilis: manifestaciones orales, revisión sistemática / Syphilis: oral manifestations, systematic review

INTRODUCCIÓN: la sífilis es una infección bacteriana, que se puede transmitir por contacto sexual o de forma congénita. Esta enfermedad consta de tres estadios, en los cuales se pueden dar diferentes manifestaciones orales. MATERIAL Y MÉTODO: se realizó una búsqueda en la base de datos PubMed, utilizándose como palabras clave: "sexually transmitted diseases", "venereal diseases", "syphilis", "primary syphilis", "secondary syphilis", "tertiary syphilis", "oral manifestations", "oral lesions". Como criterios de inclusión se emplearon: series de casos, estudios en los que el tema principal fueran las manifestaciones orales de la sífilis y trabajos en inglés y español. No hubo restricción por fecha. RESULTADOS: se seleccionaron un total de 18 artículos, la N total de pacientes fue de 201. El 10,05% padecía sífilis primaria, el 52,76% sífilis secundaria y el 36, 68% sífilis terciaria. Las lesiones orales predominantes de la sífilis primaria fueron úlceras, inflamación, chancro sifilítico; en la sífilis secundaria se apreciaban placas mucosas, lesiones eritematosas, inflamación, lesiones papulares, lesiones maculares, lesiones erosivas; en la sífilis terciaria aparecen gomas sifilíticos, lesiones leucoplásicas y atrofia lingual. DISCUSIÓN: la sífilis es una infección bacteriana que puede simular diversas enfermedades, es muy importante tenerla en cuenta a la hora de realizar el diagnóstico diferencial de diversas lesiones orales, sobre todo aquellas que se presentan de forma ulcerosa, indurada y asintomática

INTRODUCTION: syphilis is a bacterial infection, which is transmitted by sexual contact or congenitally. This disease develops in three stages, in which different oral manifestations can occur. MATERIAL AND METHOD: a search was made in the PubMed database, using as keywords: "sexually transmitted diseases", "venereal diseases", "syphilis", "primary syphilis", "secondary syphilis", "tertiary syphilis", "Oral manifestations", "oral lesions". The inclusion criteria were: case series, studies in which the main theme was the oral manifestations of syphilis and works in English and Spanish. There was no restriction by date. RESULTS: a total of 18 articles were selected, the total sample of patients was 201. 10.05% had primary syphilis, 52.76% secondary syphilis and 36, 68% tertiary syphilis. The predominant oral lesions of primary syphilis were ulcers, inflammation, syphilitic chancre; in secondary syphilis there were mucous patches, erythematous lesions, inflammation, papular lesions, macular lesions, erosive lesions; in tertiary syphilis, syphilitic gums, leukoplastic lesions and lingual atrophy. DISCUSSION: Syphilis is a bacterial infection that can simulate various diseases, it is very important to take it into account when making the differential diagnosis of various oral lesions, especially those that occur in an ulcerative, indurated and asymptomatic form

Longitudinal investigation of nasopharyngeal pneumococcal carriage in early childhood: The PATCH birth cohort study.

Streptococcus pneumoniae is a common cause of infectious diseases such as pneumonia and sepsis. Its colonization is thought to be the first step in the development of invasive pneumococcal diseases. This study aimed to investigate pneumococcal colonization patterns in early childhood. A longitudinal birth cohort study was conducted for investigating nasopharyngeal colonized pneumococci at 1, 6, 12, 18, 24, and 36 months of age, particularly focusing on the serotype distribution and antimicrobial susceptibilities. Pneumococcal conjugate vaccine (PCV) effect on nasopharyngeal colonization was also assessed. During 2013-2017, 855 infants were enrolled and a total of 107 isolates were recovered from 95 infants during the first three years of life. In this period, the prevalence of pneumococcal colonization increased, with values ranging from 0.2% (2/834) at 1 month of age to 5.9% (19/323) at 36 months of age. The investigation of serotype revealed that 81.1% (73/90) belonged to the non-PCV13 serotypes-23A, 15A, 15C, and 15B. Moreover, PCV13 serotypes significantly decreased during 2014-2015, when routine PCV13 vaccination was initiated in Taiwan. PCV13 introduction may lead to the reduction in the rates of pneumococcal isolates resistant (R) to penicillin. Under conditional PCV13 vaccination, pneumococcal isolates primarily belonged to non-PCV13 serotypes. This non-PCV13 serotype replacement exhibited lower rates of penicillin R isolates, suggesting that PCV13 administration may reduce the antibiotic-nonsusceptible pneumococcal disease burden and antibiotic use.