Impact of the COVID-19 pandemic on Haemophilus influenzae infections in pediatric patients hospitalized with community acquired pneumonia.

The COVID-19 pandemic has altered the infection landscape for many pathogens. This retrospective study aimed to compare Haemophilus influenzae (H. influenzae) infections in pediatric CAP patients hospitalized before (2018-2019) and during (2020-2022) the COVID-19 pandemic. We analyzed the clinical epidemiology and antimicrobial resistance (AMR) patterns of H. influenzae from a tertiary hospital in southwest China. A total of 986 pediatric CAP patients with H. influenzae-associated infections were included. Compared to 2018, the positivity rate increased in 2019 but dropped significantly in 2020. Although it rose in the following 2 years, the rate in 2022 remained significantly lower than in 2019. Patients' age during the pandemic was significantly higher than in 2018 and 2019, while gender composition remained similar across both periods. Notably, there were significant changes in co-infections with several respiratory pathogens during the pandemic. Resistance rates of H. influenzae isolates to antibiotics varied, with the highest resistance observed for ampicillin (85.9%) and the lowest for cefotaxime (0.0%). Resistance profiles to various antibiotics underwent dramatic changes during the COVID-19 pandemic. Resistance to amoxicillin-clavulanate, cefaclor, cefuroxime, trimethoprim-sulfamethoxazole, and the proportion of multi-drug resistant (MDR) isolates significantly decreased. Additionally, MDR isolates, alongside isolates resistant to specific drugs, were notably prevalent in ampicillin-resistant and ß-lactamase-positive isolates. The number of pediatric CAP patients, H. influenzae infections, and isolates resistant to certain antibiotics exhibited seasonal patterns, peaking in the winter of 2018 and 2019. During the COVID-19 pandemic, sharp decreases were observed in February 2020, and there was no resurgence in December 2022. These findings indicate that the COVID-19 pandemic has significantly altered the infection spectrum of H. influenzae in pediatric CAP patients, as evidenced by shifts in positivity rate, demographic characteristics, respiratory co-infections, AMR patterns, and seasonal trends.

Quercetin Protects Blood-Brain Barrier Integrity via the PI3K/Akt/Erk Signaling Pathway in a Mouse Model of Meningitis Induced by Glaesserella parasuis.

Glaesserella parasuis (G. parasuis) causes serious inflammation and meningitis in piglets. Quercetin has anti-inflammatory and anti-bacterial activities; however, whether quercetin can alleviate brain inflammation and provide protective effects during G. parasuis infection has not been studied. Here, we established a mouse model of G. parasuis infection in vivo and in vitro to investigate transcriptome changes in the mouse cerebrum and determine the protective effects of quercetin on brain inflammation and blood-brain barrier (BBB) integrity during G. parasuis infection. The results showed that G. parasuis induced brain inflammation, destroyed BBB integrity, and suppressed PI3K/Akt/Erk signaling-pathway activation in mice. Quercetin decreased the expression of inflammatory cytokines (Il-18, Il-6, Il-8, and Tnf-α) and BBB-permeability marker genes (Mmp9, Vegf, Ang-2, and Et-1), increased the expression of angiogenetic genes (Sema4D and PlexinB1), reduced G. parasuis-induced tight junction disruption, and reactivated G. parasuis-induced suppression of the PI3K/Akt/Erk signaling pathway in vitro. Thus, we concluded that quercetin may protect BBB integrity via the PI3K/Akt/Erk signaling pathway during G. parasuis infection. This was the first attempt to explore the protective effects of quercetin on brain inflammation and BBB integrity in a G. parasuis-infected mouse model. Our findings indicated that quercetin is a promising natural agent for the prevention and treatment of G. parasuis infection.

An antibacterial, multifunctional nanogel for efficient treatment of neutrophilic asthma.

Asthma is a chronic and heterogeneous disease affecting the lungs and respiratory tract. In particular, the neutrophil subtype of asthma was described as persistent, more severe, and corticosteroid-resistant. Growing evidence suggested that nontypeable Haemophilus influenzae (NTHi) infection contributes to the development of neutrophilic asthma, exacerbating clinical symptoms and increasing the associated medical burden. In this work, arginine-grafted chitosan (CS-Arg) was ionically cross-linked with tris(2-carboxyethyl) phosphine (TCEP), and a highly-efficient antimicrobial agent, poly-ε-L-Lysine (ε-PLL), was incorporated to prepare ε-PLL/CS-Arg/TCEP (ECAT) composite nanogels. The results showed that ECAT nanogels exhibited highly effective inhibition against the proliferation of NTHi, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In addition, ECAT nanogels could effectively inhibit the formation of mucins aggregates in vitro, suggesting that the nanogel might have the potential to destroy mucin in respiratory disease. Furthermore, in the ovalbumin (OVA)/NTHi-induced Balb/c mice model of neutrophilic asthma, the number of neutrophils in the alveolar lavage fluid and the percentage of inflammatory cells in the blood were effectively reduced by exposure to tower nebulized administration of ECAT nanogels, and reversing airway hyperresponsiveness (AHR) and reducing inflammation in neutrophilic asthma mice. In conclusion, the construction of ECAT nanogels was a feasible anti-infective and anti-inflammatory therapeutic strategy, which demonstrated strong potential in the clinical treatment of neutrophilic asthma.

The Effect of Ophthalmic Antibiotics on Clinical Outcomes and Transmissibility of Conjunctivitis Associated with Haemophilus influenzae versus Other Pathogens: Secondary Analysis of a Randomized Controlled Trial.

Transmission rates among children with conjunctivitis were low and antibiotic use was not associated with reduced transmission. Policies recommending exclusion from daycare and school for conjunctivitis should be scrutinized as they may not reduce transmission and may increase unnecessary antibiotic use.

Haemophilus parainfluenzae infective endocarditis complicated by multiorgan septic emboli.

Infective endocarditis (IE) caused by Haemophilus parainfluenzae is a rare but serious condition if not diagnosed and treated promptly. In this article, we describe a patient with H. parainfluenzae IE who initially presented with non-specific symptoms but subsequently developed multiple sequelae of IE. The diagnosis of IE was made based on clinical, echocardiographic, radiological and microbiological findings. He was treated successfully with a mitral valve replacement along with 4 weeks of intravenous antibiotic therapy. Our case highlights the importance of obtaining a thorough history and a complete physical examination to ensure an early diagnosis of IE.

Characterization of Ceftriaxone-Resistant Haemophilus influenzae Among Korean Children.

BACKGROUND: Haemophilus influenzae is a frequently encountered pathogen responsible for respiratory tract infections in children. Following the detection of ceftriaxone-resistant H. influenzae at our institution, we aimed to investigate the resistance mechanisms of ceftriaxone in H. influenzae, with a particular focus on alterations in penicillin-binding protein 3 (PBP3) and ß-lactamase production. METHODS: Among H. influenzae isolates collected at Asan Medical Center Children's Hospital from March 2014 to April 2019, ceftriaxone-resistant strains by the disk-diffusion test were included. Ceftriaxone minimum inhibitory concentrations (MICs) were determined using the E-test according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The presence of ß-lactamase was assessed through cefinase test and TEM-1/ROB-1 polymerase chain reaction (PCR). PBP3 alterations were explored via ftsI gene sequencing. RESULTS: Out of the 68 collected strains, 21 exhibited resistance to ceftriaxone in disk diffusion tests. Two strains were excluded due to failed subculture. Among 19 ceftriaxone-resistant H. influenzae isolates, eighteen were non-typeable H. influenzae, and twelve were positive for TEM-1 PCR. Isolates were classified into groups II (harboring only N526K, n = 3), III (N526K+S385T, n = 2), III+ (S385T+L389F+N526K, n = 11), and III-like+ (S385T+L389F+R517H, n = 3) according to the PBP3 alteration pattern. With a median ceftriaxone MIC of 0.190 mg/L (range, 0.008-0.750), the median ceftriaxone MIC was the highest in group III-like+ (0.250 mg/L), followed by groups III+ (0.190 mg/L), III (0.158 mg/L), and II (0.012 mg/L). All three strains belonging to group II, which did not harbor the S385T substitution, had ceftriaxone MICs of ≤ 0.125 mg/L. CONCLUSION: The emergence of ceftriaxone-resistant H. influenzae with ceftriaxone MIC values of up to 0.75 mg/L was observed even in children in South Korea, with most associated with S385T and L389F substitutions. The N526K mutation alone does not significantly impact ceftriaxone resistance. Further large-scale studies are essential to investigate changes in antibiotic resistance patterns and factors influencing antibiotic resistance in H. influenzae isolated from pediatric patients in Korea.

Haemophilus influenzae endocarditis: a case report and literature review.

INTRODUCTION: Haemophilus influenzae (HI) is an exceedingly rare cause of infective endocarditis (IE). CASE PRESENTATION/METHODS: We present a case of a 90-year-old female diagnosed with HI-IE involving the native tricuspid valve in the absence of traditional risk factors for right-sided endocarditis. She was treated with a 5-week course of IV Ampicillin from negative cultures and suffered no complications. We also conducted a thorough literature review through PubMed and Google Scholar, which yielded a mere 15 reported cases of HI-IE. RESULTS: Fourteen of the reported HI-IE cases included epidemiological data, showing no gender predominance. The mean age of the subjects was 39.5, with the mitral valve being the most implicated (64%) and tricuspid valve involvement being rare (21%). CONCLUSION: Native tricuspid valve IE is an uncommon entity, especially in the absence of IV drug use. Haemophilus influenzae is an extremely rare cause of IE, with a literature review showing merely 15 reported cases. This article cites the 16th case of HI-IE published in the literature.

17ß-estradiol Attenuates the Middle Ear Inflammatory Response to Nontypeable Haemophilus influenzae.

OBJECTIVES: 17ß-estradiol (E2) is a steroidal hormone with immunomodulatory functions that play a role in infectious and inflammatory diseases. E2 was recently identified as the leading upstream regulator of differentially expressed genes in a comparative RNA sequencing study of pediatric patients with otitis media (OM) versus OM-free counterparts and may therefore play a role in the inflammatory response to bacterial otopathogens during pediatric OM. This study examined the effect of E2 on bacterial-induced inflammatory cytokine expression in an in vitro pediatric OM model. METHODS: An immortalized middle ear (ME) epithelial cell line, ROM-SV40, was developed from a pediatric recurrent OM patient. The culture was exposed to E2 at physiological levels for 1-48 h prior to 6 h-stimulation with nontypeable Haemophilus influenzae (NTHi) whole cell lysate. TNFA, IL1B, IL6, and IL8 were assayed by qPCR and ELISA. RESULTS: E2 pretreatment (24 h) abrogated NTHi induction of IL6; a longer pretreatment (1-10 nM, 48 h) abrogated IL1B induction (p < 0.05). E2 pretreatment (5 nM, 48 h) abrogated NTHi-induced IL8 secretion (p = 0.017). CONCLUSION: E2 pretreatment partially rescued NTHi-induced cytokine production by ME epithelia. These data support a role for E2 in moderating the excessive inflammatory response to middle ear infection that contributes to OM pathophysiology. LEVELS OF EVIDENCE: NA Laryngoscope, 134:3815-3819, 2024.

Pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH) in the German CAPNETZ-Cohort.

OBJECTIVES: The objective of this study was to identify the pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH), and to compare it with a matched HIV negative group in order to reassess therapeutic strategies for PLWH. METHODS: Seventy-three (n = 73) PLWH (median CD4 3-6 months before CAP: 515/µl; SD 309) with community acquired pneumonia (CAP) were matched with 218 HIV-negative CAP controls in a prospective study design. Pathogen identifications used blood culture, samples from the upper and lower respiratory tract (culture and multiplex PCR) and urinary pneumococcal and legionella antigen test. RESULTS: Although the vaccination rate among PLWH with CAP was significantly higher (pneumococcal vaccination: 27.4 vs. 8.3%, p < 0.001; influenza vaccination: 34.2 vs. 17.4%, p = 0.009), pneumococci were found most frequently as pathogen among both PLWH (n = 19/21.3%) and controls (n = 34/17.2%; p = 0.410), followed by Haemophilus influenzae (PLWH, n = 12/13.5%, vs. controls, n = 25 / 12.6%; p = 0.850). Staphylococcus aureus was found equally in 20.2 and 19.2% in PLWH and controls, but infection or colonization could not be distinguished. Mortality during 6-month follow-up was significantly higher for PLWH (5/73, or 6.8%) versus controls (3/218, or 1.4%), however with lower case numbers than previously reported. Typical HIV-associated pathogens such as Pneumocystis jirovecii were found only exceptionally. CONCLUSIONS: Our study underscores the persistent clinical burden of CAP for PLWH. From pathogen perspective, empirical antibiotic treatment for CAP in PLWH on antiretroviral therapy should cover pneumococci and Haemophilus influenzae and may be adopted from valid common recommendations.

The Association between Transformation Ability and Antimicrobial Resistant Potential in Haemophilus influenzae.

The prevalence of quinolone low-susceptible Haemophilus influenzae has increased in Japan. Low quinolone susceptibility is caused by point mutations in target genes; however, it can also be caused by horizontal gene transfer via natural transformation. In this study, we examined whether this horizontal gene transfer could be associated with resistance to not only quinolones but also other antimicrobial agents. Horizontal transfer ability was quantified using the experimental transfer assay method for low quinolone susceptibility. Further, the association between horizontal transfer ability and resistance to ß-lactams, the first-choice drugs for H. influenzae infection, was investigated. The transformation efficiency of 50 clinical isolates varied widely, ranging from 102 to 106 colony forming unit (CFU) of the colonies obtained by horizontal transfer assay. Efficiency was associated with ß-lactam resistance caused by ftsI mutations, indicating that strains with high horizontal transfer ability acquired quinolone low-susceptibility as well as ß-lactam resistance more easily. Strains with high transformation efficiency increased the transcript level of comA, suggesting that enhanced com operon was associated with a high DNA uptake ability. Overall, this study revealed that the transformation ability of H. influenzae was associated with multiple antimicrobial resistance. Increase in the number of strains with high horizontal transformation ability has raised concerns regarding the rapid spread of antimicrobial-resistant H. influenzae.

Molecular characterization of multidrug-resistant non-typeable Haemophilus influenzae with high-level resistance to cefuroxime, levofloxacin, and trimethoprim-sulfamethoxazole.

BACKGROUND: Non-typeable Haemophilus influenzae (NTHi) has become the major cause of invasive H. influenzae diseases in the post-H. influenzae type b vaccine era. The emergence of multidrug-resistant (MDR) NTHi is a growing public health problem. Herein, we investigated the molecular basis of MDR in NTHi. The isolated NTHi were subjected to antimicrobial susceptibility testing for 12 agents. Whole genome and plasmid sequencing were conducted and analyzed to identify significant genetic variations and plasmid-encoded genes conferred antibiotic resistance. RESULTS: Thirteen (50%) MDR NTHi isolates were obtained; of these, 92.3% were non-susceptible to ampicillin, 30.8% to amoxicillin-clavulanate, 61.5% to cefuroxime, 61.5% to ciprofloxacin/levofloxacin, 92.3% to trimethoprim-sulfamethoxazole, 30.8% to tetracycline, and 7.7% to azithromycin. Eight ampicillin-resistant isolates were ß-lactamase positive; of these, 6 carried blaTEM-1 and 2 carried blaROB-1, whereas 4 were ß-lactamase negative. Genetic variations in mrdA, mepA, and pbpG were correlated with amoxicillin-clavulanate non-susceptibility, whereas variations in ftsI and lpoA conferred cefuroxime resistance. Five variations in gyrA, 2 in gyrB, 3 in parC, 1 in parE, and 1 in the parC-parE intergenic region were associated with levofloxacin/ciprofloxacin non-susceptibility. Among these genes, 8 variations were linked to high-level levofloxacin resistance. Six variations in folA were associated with trimethoprim-sulfamethoxazole resistance. Plasmid-bearing tet(B) and mef(A) genes were responsible for tetracycline and azithromycin resistance in 4 and 1 MDR isolates, respectively. CONCLUSIONS: This study clarified the molecular epidemiology of MDR in NTHi. This can benefit the monitoring of drug resistance trends in NTHi and the adequate medical management of patients with NTHi infection.

Haemophilus influenzae septicaemia and urinary tract infection associated with nefrocalcinosis: case report.

Haemophilus influenzae is an uncommon uropathogen with fastidious growth requirements, which must be taken into consideration in the diagnostic process. We present a rare case of urosepsis with H. influenzae in a young patient with nefrocalcinosis.

A case of diffuse panbronchiolitis caused by Mycoplasma amphoriforme.

Mycoplasma amphoriforme is a novel specie which was discovered in 2003 and associated with congenital immune deficiency. It has been described as an underlying cause of bronchopneumonia. There is limited description of the in vitro sensitivities. In this article, we present the first description of M. amphoriforme as the causative agent of diffuse panbronchiolitis in a patient with X-linked hypogammaglobulinema and bronchiectasis, with symptoms improved by treatment with azithromycin. We also describe the difficulty obtaining this organism through routine culture and the need to consider culture independent methods of recovery when the suspicion is high.

Septic Arthritis Caused by Haemophilus parainfluenzae : A Pediatric Case Report and Literature Review.

We report a healthy 5-year-old boy without apparent risk factors who developed septic arthritis of the hip from Haemohilus parainfluenzae infection. A literature review revealed only 4 pediatric cases of osteoarticular infection caused by this pathogen. To our knowledge, our case may be the first pediatric case of septic arthritis of the hip caused by H. parainfluenzae .

In Vivo Genome-Wide Gene Expression Profiling Reveals That Haemophilus influenzae Purine Synthesis Pathway Benefits Its Infectivity within the Airways.

Haemophilus influenzae is a human-adapted bacterial pathogen that causes airway infections. Bacterial and host elements associated with the fitness of H. influenzae within the host lung are not well understood. Here, we exploited the strength of in vivo-omic analyses to study host-microbe interactions during infection. We used in vivo transcriptome sequencing (RNA-seq) for genome-wide profiling of both host and bacterial gene expression during mouse lung infection. Profiling of murine lung gene expression upon infection showed upregulation of lung inflammatory response and ribosomal organization genes, and downregulation of cell adhesion and cytoskeleton genes. Transcriptomic analysis of bacteria recovered from bronchoalveolar lavage fluid samples from infected mice showed a significant metabolic rewiring during infection, which was highly different from that obtained upon bacterial in vitro growth in an artificial sputum medium suitable for H. influenzae. In vivo RNA-seq revealed upregulation of bacterial de novo purine biosynthesis, genes involved in non-aromatic amino acid biosynthesis, and part of the natural competence machinery. In contrast, the expression of genes involved in fatty acid and cell wall synthesis and lipooligosaccharide decoration was downregulated. Correlations between upregulated gene expression and mutant attenuation in vivo were established, as observed upon purH gene inactivation leading to purine auxotrophy. Likewise, the purine analogs 6-thioguanine and 6-mercaptopurine reduced H. influenzae viability in a dose-dependent manner. These data expand our understanding of H. influenzae requirements during infection. In particular, H. influenzae exploits purine nucleotide synthesis as a fitness determinant, raising the possibility of purine synthesis as an anti-H. influenzae target. IMPORTANCE In vivo-omic strategies offer great opportunities for increased understanding of host-pathogen interplay and for identification of therapeutic targets. Here, using transcriptome sequencing, we profiled host and pathogen gene expression during H. influenzae infection within the murine airways. Lung pro-inflammatory gene expression reprogramming was observed. Moreover, we uncovered bacterial metabolic requirements during infection. In particular, we identified purine synthesis as a key player, highlighting that H. influenzae may face restrictions in purine nucleotide availability within the host airways. Therefore, blocking this biosynthetic process may have therapeutic potential, as supported by the observed inhibitory effect of 6-thioguanine and 6-mercaptopurine on H. influenzae growth. Together, we present key outcomes and challenges for implementing in vivo-omics in bacterial airway pathogenesis. Our findings provide metabolic insights into H. influenzae infection biology, raising the possibility of purine synthesis as an anti-H. influenzae target and of purine analog repurposing as an antimicrobial strategy against this pathogen.

Clinical characteristics of 32 cases of diffuse panbronchiolitis. / 32例弥漫性泛细支气管炎的临床特征.

OBJECTIVES: Diffuse panbronchiolitis (DPB) is a chronic airway inflammation with low specificity and its diagnosis is often missed or delayed. This study aims to summarize the clinical characteristics and treatment of DPB in order to improve the understanding and diagnosis of the disease. METHODS: The clinical data of 32 DPB patients were collected, analyzed and summarized from March 1, 2013 to March 1, 2022 in the Second Xiangya Hospital of Central South University. The basic information, clinical manifestations, laboratory tests, pulmonary function, imaging tests, treatment, and regression of patients were analyzed. RESULTS: A total of 32 patients were enrolled in the final analysis, with a male-to-female ratio at 1.67. The median age at symptom onset was 26.5 (11.0-69.0) years, and the median age of diagnosis was 47.5 (16.0-77.0) years. All patients presented with chronic cough and copious sputum production. A total of 26 patients had post activity shortness of breath and 14 patients had a positive result (blood cold agglutination test titer≥1꞉64). Pulmonary function examination was performed in 31 patients, 18 patients showed mixed pulmonary ventilation dysfunction, 12 patients showed obstructive pulmonary ventilation, and 1 patient had normal pulmonary ventilation function. A total of 31 patients had a bilateral, diffuse, small nodule pattern on chest CT. All patients were treated with macrolides. A total of 31 patients showed improvement, and 20 patients showed improvement in partial pressure of oxygen and blood oxygen saturation compared with before at discharge. A total of 12 patients were re-examined by chest CT after completing macrolides treatment, 6 cases showed less diffuse nodules, 5 cases showed no significant changes, and 1 case showed more diffuse nodules, which indicated the disease progression. Seven patients received pulmonary function tests after completing macrolides treatment, forced expiratory volume in one second (FEV1) and FEV1/forced vital capacitywere improved, but forced expiratory flow at 25% of vital capacity did not change significantly. CONCLUSIONS: The clinical manifestations of DPB are nonspecific. Early diagnosis and treatment are very important for the prognosis of patients.

Characterization of Serotypes and Molecular Drug Resistance Patterns of Haemophilus influenzae in Kunming Children.

The present study aimed to determine the capsular serotype distribution and antimicrobial drug resistance patterns of Haemophilus influenzae from children in the Kunming region of China. This information could guide policymakers in clinical treatment. In the present study, H. influenzae isolates were tested for their serotypes, antimicrobial susceptibility pattern, and presence of ß-lactamases. One-hundred forty-eight H. influenzae strains isolated from children 0-2 years old were investigated for capsular types by glass slide agglutination and molecular methods, and biotyped by the biochemical reactions. The drug resistance-encoding genes TEM-1, ROB-1, and the ftsI gene mutations PBP3-3, and PBP3-BLN were detected with real-time quantitative polymerase chain reaction (qPCR). The prevalence of ß-lactamase-producing strains (60.3%) was significantly higher (p < 0.05) than non-enzyme-producing strains. ß-Lactamase-producing strains were multidrug resistant to various antibiotics such as ampicillin, tetracycline, sulfamethoxazole/trimethoprim, chloramphenicol, cefuroxime, and cefaclor. Among ß-lactamase-producing strains, the detection rates of the TEM-1, PBP3-BLN, PBP3-s, and ROB-1 were 54.1%, 18.9%, 11.8%, and 6.9%, respectively. The biotyping results show that most H. influenzae strains were of type II and III. Non-typeable H. influenzae (NTHi) accounted for 89.3% of the strains. NTHi strains were the most prevalent in this region; most belonged to biological types II and III. ß-Lactamase-positive ampi-cillin-resistant (BLPAR) strains were prevalent among H. influenzae isolates in this region.

Molecular Epidemiology of Haemophilus influenzae Strains with Reduced Susceptibility and Genetic Profiles of Resistance in the Postvaccination Period.

Haemophilus influenzae serotype b has been the main cause of invasive infections in children, during the prevaccination period. More than 20 years after the introduction of the conjugate vaccine against Hib, HiNT has emerged as the cause of localized infections in children and adults. The main objective of this work is to evaluate the susceptibility and resistance mechanisms of H. influenzae strains from carriers and describe the molecular epidemiology and their clonal relationships by multilocus sequence typing (MLST). Sixty-nine strains from clinical cases and asymptomatic carriers from 2009 to 2019 were analyzed, confirmed as H. influenzae, and serotyped by polymerase chain reaction. The susceptibility to antibiotics was evaluated by E-test strips. Genotyping was performed by MLST. HiNT was the most frequent in all age groups. Resistance to ampicillin, sulfamethoxazole+trimethoprim, and amoxicillin+clavulanic acid was detected, with the production of ß-lactamase being the main resistance mechanism. Among 21 HiNT strains with complete allelic MLST profiles, 19 new sequence types were described, reinforcing the already reported heterogeneity of nontypeable strains, and only one clonal complex (cc-1355) was observed. Our results show a high percentage of colonization regardless of age, increased antimicrobial resistance, and high genetic diversity, along with an increased number of cases caused by HiNT strains. These findings reinforce the need for continuous surveillance for HiNT strains as it has been reported worldwide after the introduction of the Hib conjugate vaccine.