High Prevalence of Non-typeable Haemophilus influenzae and Haemophilus haemolyticus Among Vaccinated Children with Community-Acquired Pneumonia in Vietnam.

Among 467 children under five hospitalized with community-acquired pneumonia, the prevalence of Haemophilus influenzae or Haemophilus haemolyticus was 60.8%, all cases were non-typable H. influenzae (NTHi) or H. haemolyticus. NTHi/H. haemolyticus PCR detection was associated with about twice the risk for severe disease. The results highlight the need for increased awareness and research efforts to investigate the role of NTHi/H. haemolyticus in severe CAP among children.

Percutaneous Management of Septic Left Anterior Descending Coronary Occlusion Following Minimally Invasive Surgery for Mitral Valve Infective Endocarditis.

Coronary artery embolization is an unusual complication following infective endocarditis (IE) surgery. A 43-year-old woman developed an anterior ST-elevation myocardial infarction (STEMI) with acute left anterior descending artery occlusion due to septic emboli during the immediate postoperative period following minimally invasive mitral valve repair for IE. It was successfully treated with thromboaspiration and balloon angioplasty. Coronary septic emboli should be part of the differential diagnosis in patients presenting with STEMI during the early postoperative period for IE.

Exploring the signature gut and oral microbiome in individuals of specific Ayurveda prakriti.

Diagnosis and treatment of various diseases in Ayurveda, the Indian system of medicine, relies on 'prakriti' phenotyping of individuals into predominantly three constitutions, kapha, pitta and vata. Recent studies propose that microbiome play an integral role in precision medicine. A study of the relationship between prakriti - the basis of personalized medicine in Ayurveda and that of gut microbiome, and possible biomarker of an individual's health, would vastly improve precision therapy. Towards this, we analyzed bacterial metagenomes from buccal (oral microbiome) and fecal (gut microbiome) samples of 272 healthy individuals of various predominant prakritis. Major bacterial genera from gut microbiome included Prevotella, Bacteroides and Dialister while oral microbiome included Streptococcus, Neisseria, Veilonella, Haemophilus, Porphyromonas and Prevotella. Though the core microbiome was shared across all individuals, we found prakriti specific signatures such as preferential presence of Paraprevotella and Christensenellaceae in vata individuals. A comparison of core gut microbiome of each prakriti with a database of 'healthy' microbes identified microbes unique to each prakriti with functional roles similar to the physiological characteristics of various prakritis as described in Ayurveda. Our findings provide evidence to Ayurvedic interventions based on prakriti phenotyping and possible microbial biomarkers that can stratify the heterogenous population and aid in precision therapy.

Comparative analysis of the pulmonary microbiome in healthy and diseased pigs.

The lungs possess an effective antimicrobial system and a strong ability to eliminate microorganisms in healthy organisms, and were once considered sterile. With the development of culture-independent sequencing technology, the richness and diversity of porcine lung microbiota have been gaining attention. In order to study the relationship between lung microbiota and porcine respiratory disease complex (PRDC), the lung microbiota in healthy and diseased swine bronchoalveolar lavage fluids were analyzed and compared using the Illumina MiSeq sequencing platform. The predominant microbial communities of healthy and diseased swine were similar at the phylum level, mainly composed of Proteobacteria, Firmicutes, Tenericutes, and Bacteroidetes. However, the bacterial taxonomic communities of healthy and diseased swine differed at the genus level. The higher relative abundances of Lactococcus, Enterococcus, Staphylococcus, and Lactobacillus genera in healthy swine might provide more benefits for lung health, while the enhanced richness of Streptococcus, Haemophilus, Pasteurella, and Bordetella genera in diseased swine might be closely related to pathogen invasion and the occurrence of respiratory disease. In conclusion, the observed differences in the richness and diversity of lung microbiota can provide novel insights into their relationship with PRDC. Analyses of swine lung microbiota communities might produce an effective strategy for the control and prevention of respiratory tract infections.

Severity of Respiratory Infections With Seasonal Coronavirus Is Associated With Viral and Bacterial Coinfections.

The clinical presentation of human coronavirus (HCoV) infections in children varies strongly. We show that children with an HCoV-associated lower respiratory tract infection more frequently had respiratory syncytial virus codetected and higher abundance of Haemophilus influenzae/haemolyticus than asymptomatic HCoV carriers as well as children with a non-HCoV-associated lower respiratory tract infection. Viral and bacterial cooccurrence may drive symptomatology of HCoV-associated infections including coronavirus disease 2019.

Haemophilus urethritis in males: A series of 30 cases.

INTRODUCTION AND OBJECTIVES: Pathogens such as Haemophilus spp. have been associated with non-gonococcal urethritis, but their role is unproven. To describe the clinical characteristics and therapeutic outcomes in male patients diagnosed with Haemophilus spp. urethritis. METHODS: We carried out a retrospective study of all patients who presented to our hospital (in either the emergency department or the outpatient clinic) between July 2016 and April 2018 in whom Haemophilus spp. was isolated in the urethral samples. We enrolled 30 men with Haemophilus spp.-positive urethritis, including coinfections with Neisseria gonorrhoeae and Chlamydia trachomatis. Clinical, laboratory, demographic, and behavioral data were obtained by reviewing medical histories. RESULTS: The mean age of the patients was 36.6 years (range 21-87). Seventeen patients (63%) reported being exclusively heterosexual. Three patients (10%) were HIV infected, all of them with an undetectable viral load. The most common clinical presentation was mucopurulent urethral discharge, in 13 patients (43%). The antibiotic treatment achieved a complete clinical resolution in 73%. CONCLUSIONS: Haemophilus urethritis affected men regardless of their sexual orientation or HIV status. Unprotected oral sex may play a role in its transmission. The limitations of the study preclude verification of the pathogenic role of Haemophilus spp. in acute urethritis, but clinical response after antibiotic treatment suggests that Haemophilus spp. can play such a role.

Bacterial composition of nasal discharge in children based on highly accurate 16S rRNA gene sequencing analysis.

Nasopharyngeal colonization by bacteria is a prerequisite for progression to respiratory disease and an important source of horizontal spread within communities. We aimed to perform quantitative analysis of the bacterial cells and reveal the microbiota of the nasal discharge in children at the species level based on highly accurate 16S rRNA gene sequencing. This study enrolled 40 pediatric patients with rhinorrhea. The bacterial cells in the nasal discharge were counted by epifluorescence microscopic analysis. The microbiota was analyzed by using the 16S rRNA gene clone library sequencing method. We demonstrated that a high abundance (median 2.2 × 107 cells/mL) of bacteria was contained in the nasal discharge of children. Of the 40 samples, 37 (92.5%) were dominated by OTUs corresponding to Haemophilus aegyptius/influenzae, Moraxella catarrhalis/nonliquefaciens, or Streptococcus pneumoniae. These samples showed higher cell abundance and lower alpha diversity than the remaining three samples in which the other bacteria coexisted. In addition, 12 sequences with low homology to type strains were considered as previously unknown bacterial lineages. In conclusion, the nasal discharge of most young children contains a large amount of respiratory pathogens and several unknown bacteria, which could not only cause endogenous infection but also be a source of transmission to others.

Longitudinal Changes in Early Nasal Microbiota and the Risk of Childhood Asthma.

OBJECTIVES: Although the airway microbiota is a highly dynamic ecology, the role of longitudinal changes in airway microbiota during early childhood in asthma development is unclear. We aimed to investigate the association of longitudinal changes in early nasal microbiota with the risk of developing asthma. METHODS: In this prospective, population-based birth cohort study, we followed children from birth to age 7 years. The nasal microbiota was tested by using 16S ribosomal RNA gene sequencing at ages 2, 13, and 24 months. We applied an unsupervised machine learning approach to identify longitudinal nasal microbiota profiles during age 2 to 13 months (the primary exposure) and during age 2 to 24 months (the secondary exposure) and examined the association of these profiles with the risk of physician-diagnosed asthma at age 7 years. RESULTS: Of the analytic cohort of 704 children, 57 (8%) later developed asthma. We identified 4 distinct longitudinal nasal microbiota profiles during age 2 to 13 months. In the multivariable analysis, compared with the persistent Moraxella dominance profile during age 2 to 13 months, the persistent Moraxella sparsity profile was associated with a significantly higher risk of asthma (adjusted odds ratio, 2.74; 95% confidence interval, 1.20-6.27). Similar associations were observed between the longitudinal changes in nasal microbiota during age 2 to 24 months and risk of asthma. CONCLUSIONS: Children with an altered longitudinal pattern in the nasal microbiota during early childhood had a high risk of developing asthma. Our data guide the development of primary prevention strategies (eg, early identification of children at high risk and modification of microbiota) for childhood asthma. These observations present a new avenue for risk modification for asthma (eg, microbiota modification).

The microbiomes of adenoid and middle ear in children with otitis media with effusion and hypertrophy from a tertiary hospital in China.

INTRODUCTION: Otitis media with effusion (OME) is one of the most common pediatric diseases worldwide. Several studies have analyzed the diversity of the microbiomes found in the middle ear effusions (MEEs) of populations from developed countries. However, no microbiological studies of MEEs from Chinese children with OME have been reported. This study investigated the middle ear and adenoid microbiological profiles of children with OME, and compared the microbial flora of the adenoid between children with and without otitis media. METHODS: MEEs and adenoid swabs were acquired from 15 children undergoing ventilation tube insertion and adenoidectomy. Adenoid swabs from 15 patients with no ear disease were used as controls. Samples were analyzed by 16S rRNA sequencing. Operational taxonomic units (OTUs) abundance information were normalized. Alpha diversity analyses were used to assess the richness and diversity of the microbial community for each sample. Beta diversity analyses were used to determine the inter-group variability between microbiome structure. RESULTS: Based on the mean relative abundance, the MEEs were dominated by Haemophilus (14.75%), Staphylococcus (9.37%) and Halomonas (7.85%), and the bacterial compositions of the adenoids in the OME groups were dominated by Haemophilus (21.87%), Streptococcus (19.65%), and Neisseria (5.8%). The bacterial compositions in the adenoids of the controls were dominated by Haemophilus (15.96%), Streptococcus (13.33%), and Moraxella (12.28%). Alpha diversity analyses showed that there were no significant differences in microbiome richness or diversity between the middle ear effusions (TM) and adenoids (TA) of OME subjects. Adenoid samples from OME patients (TA) and control patients (CA) were also similar. Beta diversity analyses showed that the microbiomes of the adenoids in OME patients were also similar to that of controls. However, the microbiome structure of middle ear effusions was dissimilar to those of the adenoids in OME patients according to beta diversity analyses. CONCLUSIONS: Our results confirmed the microbial diversity of MEEs among Chinese children. However, the dissimilar microbiome composition between samples taken from the surface of the adenoids and from the middle ear effusions challenges the conventional theory that the adenoid serves as a microbial reservoir in children with otitis media with effusion.

Haemophilus seminalis sp. nov., isolated from human semen.

Two Haemophilus-like isolates with similar biochemical characteristics, designated strains SZY H1T and SZY H2, were isolated from human semen specimens. Cells were Gram-negative, non-motile, non-acid-fast, pleomorphic rods or coccobacilli. The major fatty acids (>10 %) were C16 : 0, C14 : 0, iso-C16 : 0 and/or C14 : 0 3-OH and C16 : 1 ω6c and/or C16 : 1 ω7c. The polar lipids were determined to be phosphatidylethanolamine, phosphatidylglycerol, an unidentified phospholipid, an unidentified aminophospholipid, two unidentified polar lipids and four unidentified aminolipids. The major polyamine was found to be cadaverine. The near-full-length (1462 nt) 16S rRNA gene sequences analysis showed the two isolates were nearly identical (>99.8 %), and closely matched Haemophilus haemolyticus ATCC 33390T with 98.9-99.1 % sequence similarities. Phylogenetic analysis based on 16S rRNA gene sequences and concatenation of 30 protein markers also revealed that the isolates clustered together with H. haemolyticus ATCC 33390T, and formed a distinct lineage well separated from the other members of the genus Haemophilus. Further, the average nucleotide identity values between the two isolates and their related species were below the established cut-off values for species delineation (95 %). Based on these findings, the two isolates are considered to represent a new species of the genus Haemophilus, for which name Haemophilus seminalis sp. nov. is proposed. The type strain is SZY H1T (=NBRC 113782T=CGMCC 1.17137T).

Shifts in the bacterial community of saliva give insights on the relationship between obesity and oral microbiota in adolescents.

The current study aimed at the determination of the impact of obesity on the salivary microbiome in adolescents. Sixty subjects ranging 14-17 years old were enrolled (obese: n = 30-50% females, and normal weight: n = 30-50% females). Stimulated saliva was collected for denaturing gradient gel electrophoresis (DGGE) band patterns and massive 16S rRNA gene sequencing using the Ion Torrent platform. Overall, data analysis revealed that male subjects harbored a higher diverse salivary microbiome, defined by a significant higher richness (32.48 versus 26.74) and diversity (3.36 versus 3.20), higher Simpson values (0.96 versus 0.95) and distinct bacterial community structure considering either sex or condition (p < 0.05). Bacterial community fingerprinting analysis in human saliva showed a positive correlation with increased body mass index (BMI) in adolescents. Veillonella, Haemophilus and Prevotella occurrence was found to be affected by BMI, whereas Neisseria and Rothia occurrence was significantly impacted by sex in obese subjects. Our findings suggest that male and female adolescents may harbor a naturally distinct salivary microbiota and that obesity may specifically have an impact on their oral bacterial community. The potential dysbiotic oral microbiome in obese adolescents raises new insights on the etiology and prevention of future conditions in these populations.

Airway microbiome composition correlates with lung function and arterial stiffness in an age-dependent manner.

OBJECTIVE: To investigate age-associated changes in airway microbiome composition and their relationships with lung function and arterial stiffness among genetically matched young and elderly pairs. METHODS: Twenty-four genetically linked family pairs comprised of younger (≤40 years) and older (≥60 years) healthy participants were recruited (Total n = 48). Lung function and arterial stiffness (carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx)) were assessed. Sputum samples were collected for targeted 16S rRNA gene amplicon sequencing and correlations between microbiome composition, lung function and arterial stiffness were investigated. RESULTS: Elderly participants exhibited reductions in lung function (FEV1 (p<0.001), FVC (p<0.001) and percentage FEV1/FVC (p = 0.003)) and a 1.3-3.9-fold increase in arterial stiffness (p<0.001) relative to genetically related younger adults. Elderly adults had a higher relative abundance of Firmicutes (p = 0.035) and lower relative abundance of Proteobacteria (p = 0.014), including specific genera Haemophilus (p = 0.024) and Lautropia (p = 0.020) which were enriched in the younger adults. Alpha diversity was comparable between young and elderly pairs (p>0.05) but was inversely associated with lung function (FEV1%Predicted and FVC %Predicted) in the young (p = 0.006 and p = 0.003) though not the elderly (p = 0.481 and p = 0.696). Conversely, alpha diversity was negatively associated with PWV in the elderly (p = 0.01) but not the young (p = 0.569). Specifically, phylum Firmicutes including the genus Gemella were correlated with lung function (FVC %Predicted) in the young group (p = 0.047 and p = 0.040), while Fusobacteria and Leptotrichia were associated with arterial stiffness (PWV) in the elderly (both p = 0.004). CONCLUSION: Ageing is associated with increased Firmicutes and decreased Proteobacteria representation in the airway microbiome among a healthy Asian cohort. The diversity and composition of the airway microbiome is independently associated with lung function and arterial stiffness in the young and elderly groups respectively. This suggests differential microbial associations with these phenotypes at specific stages of life with potential prognostic implications.

Identification and Characterization of "Haemophilus quentini" Strains Causing Invasive Disease in Ontario, Canada (2016 to 2018).

Haemophilus influenzae is a well-established human pathogen capable of causing a range of respiratory and invasive diseases. Since the 1970s, it has been observed that a nontypeable cryptic genospecies of H. influenzae, most often biotype IV, has been associated with the genitourinary tracts of females and with invasive neonatal infections. This distinct genospecies has been provisionally named "Haemophilus quentini" Here, we report seven cases of invasive H. quentini disease in patients from Ontario, Canada, over a 2-year period. Significantly, while most reports of invasive disease with H. quentini to date have been in neonates, we observed five cases in adults (three in women of childbearing age and two in seniors) as well as two in neonates. Identification of H. quentini is challenging and was not possible for frontline laboratories, requiring work at the reference laboratory level. We describe in detail the biochemical results, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-Tof MS) results, and PCR results with several targets, including the 16S rRNA gene and multilocus sequence typing (MLST) genes, for the seven Ontario H. quentini isolates and several controls. Our data, combined with those of other publications, support the fact that H. quentini is distinct from H. influenzae and Haemophilus haemolyticus This organism is recognized as a pathogen of neonates, but we hypothesize that it may be underrecognized as an important pathogen in adults as well, particularly pregnant women. By sharing the detailed descriptions of these isolates, we hope to enable other laboratories to better identify H. quentini so that the true prevalence of this organism and disease can be explored.

A novel nucleic acid based bio-assay toward recognition of Haemophilus influenza using bioconjugation and DNA hybridization method.

Haemophilus influenza (H. influenza) is a gram negative coccobacillus pathogenic microorganism. H. influenza produces beta-lactamases, and it is also able to modify its penicillin-binding proteins, so it has gained resistance to the penicillin family of antibiotics. In this work, a novel sensitive approach was established for the monitoring of H. influenza using DNA based bio-assay. For the first time, specific sequence of thiolated probe of Haemophilus influenza (SH-5'-AAT TTT CCA ACT TTT TCA CCT GCA T-3') was immobilized on the surface of gold (Au) electrode. Square wave voltammetry (SWV) was carried out in toluidine blue (TB) solution for DNA hybridization and targeting of cDNA sequence of Haemophilus influenza. Field scanning electron microscope (FE-SEM) was applied to investigation of the electrode morphology and estimate of particle size. In the optimal conditions, the planned strategy could detect target DNA (5'-ATG CAG GTG AAA AAG TTG GAA AAT T-3') down to 1 ZM with a linear range from 1 µM to 1 ZM. Moreover, engineered geno-assay selectively differentiates the complementary sequence from target sequences with one, double and three base mismatch sequences.

Dysbiotic salivary microbiota in dry mouth and primary Sjögren's syndrome patients.

OBJECTIVES: Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by reduced lacrimal and salivary secretion. Sicca symptoms together with fatigue and musculoskeletal pain can significantly reduce the patients' quality of life. Furthermore, low salivary secretion may disrupt the oral microbial homeostasis. The aim of this study was to compare the salivary microbiota from pSS patients with patients with sicca symptoms not fulfilling the classification criteria for pSS (non-SS), and with healthy controls without sicca complaints. METHODS: Pellets from centrifuged chewing-stimulated whole saliva from pSS patients (n = 15), non-SS sicca patients (n = 15) and healthy controls (n = 15) were prepared. DNA was extracted and analyzed by 16S rRNA gene sequencing. The acquired sequencing data were performed using the human oral microbiome database (HOMD). RESULTS: We detected 42, 45, and 34 bacterial genera in saliva samples from pSS patients, non-SS sicca patients, and healthy controls, respectively. The most abundant genera in all samples were Prevotella, Veillonella, Streptococcus, and Haemophilus. At species level Streptococcus intermedius, Prevotella intermedia, Fusobacterium nucleatum subsp. vincentii, Porphyromonas endodontalis, Prevotella nancensis, Tannerella spp., and Treponema spp. were detected in the samples from pSS and non-SS only, while Porphyromonas pasteri was mostly found among the healthy controls. CONCLUSION: Our study indicated dysbiosis in the salivary microbiota from pSS and non-SS patients compared to healthy controls. Additionally, the results showed that the salivary microbiome in the pSS group differed significantly from the non-SS group.

Disseminated "Haemophilus quentini" infection in a patient with multiple myeloma - a case report and review of the literature.

We describe a case report of a 56-year-old male with undiagnosed multiple myeloma who had severe sepsis associated with pneumonia, meningitis, polyarthritis, and osteomyelitis related to invasive "Haemophilus quentini" infection. The genus was misidentified as H. influenzae by the common bacterial identification systems including newly introduced syndromic PCR-based methods. We review the epidemiological, clinical, and laboratory aspects of this rare, cryptic species of Haemophilus.

Pathogen reservoir hypothesis investigated by analyses of the adenotonsillar and middle ear microbiota.

INTRODUCTION: Adenotonsillar and middle ear diseases result in some of the most frequently performed operations in the pediatric population worldwide. The pathogen reservoir hypothesis (PRH) suggests that the adenoids act as a reservoir of bacteria which play a potential pathogenic role in otitis media. Evidence supporting this hypothesis is limited. This study sought to comprehensively determine and compare associations between the adenotonsillar and middle ear bacterial microbiota within individual patients via next-generation sequencing and microbial network analyses. METHODS: Bacterial 16S rRNA gene-targeted amplicon sequencing was used to determine the bacterial composition of ten pediatric patients undergoing adenotonsillectomy and ventilation tube insertion for otitis media with effusion. At the time of surgery, swabs were taken from the adenoid surface, tonsil crypts and middle ear clefts (through the myringotomy incision). RESULTS: The most abundant sequences within the bacterial community at genus level across all anatomical sites were Fusobacterium, Haemophilus, Neisseria, and Porphyromonas. There was an observable difference in the relative abundance of bacterial communities, with a higher proportion of Haemophilus and Moraxella in the adenoid when compared with the middle ear. Furthermore, only one module (consisting of 4 bacterial OTUs) from one patient was identified through microbial network analyses to be significantly associated between middle ear and adenoid. In addition, microbial network analysis revealed that the adenoid and tonsil microbiota share greater similarity than do the adenoid and middle ear. CONCLUSION: The results of this study suggest that the adenoid microenvironment does not correlate to the middle ear microenvironment. A future study at the species level, and over time, is required to further investigate whether the differing relationship between the microbiota of the adenoid and middle ear rejects the pathogen reservoir hypothesis.

The Microbiology of Complicated Acute Sinusitis among Pediatric Patients: A Case Series.

OBJECTIVE: The microbiology of pediatric complicated acute rhinosinusitis (ARS) has evolved, and our current understanding of pathogenic organisms is limited. The objectives of this study are to describe the incidence of pathogens causing complicated ARS requiring surgical intervention at our institution over a 10-year period as well as their associated treatment outcomes. STUDY DESIGN: Retrospective cohort study. SETTING: A single tertiary care children's hospital. SUBJECTS AND METHODS: Data were reviewed from all patients who underwent surgery for complicated ARS and had positive culture data from 2006 to 2016. Associations among pathogens, complications, and outcomes were analyzed with Pearson χ2 and Wilcoxon rank-sum tests. RESULTS: Eighty-nine patients met criteria. Complications included orbital infections (78%), intracranial infections (48%), Pott's puffy tumor (13%), and cavernous sinus thrombosis (9.0%). Bacterial isolates were majority polymicrobial (55%) and included Streptococcus species (58%), Staphylococcus species (49%; including methicillin-resistant S aureus [MRSA], 11%), and anaerobic bacteria (35%). S pneumoniae (9.0%), Haemophilus species (4.5%), and Moraxella catarrhalis (1.1%) were relatively uncommon. Bacterial isolates were similar among patients with all types of complications. CONCLUSION: Among a large cohort of pediatric patients with complicated ARS, most bacterial isolates were polymicrobial, with Streptococcus and Staphylococcus species contributing to the majority of cases. S aureus species, including MRSA and anaerobic pathogens, were common. The pattern of bacterial isolates was similar among patients with all types of complications of ARS. We suggest treatment for complicated ARS with broad-spectrum antibiotics with coverage for Streptococcus species, Staphylococcus species including MRSA, and anaerobic bacteria.

Haemophilus Species Isolated in Urethral Exudates as a Possible Causative Agent in Acute Urethritis: A Study of 38 Cases. / Aislamiento de Haemophilus spp. en exudados uretrales como posible agente etiológico de uretritis aguda: estudio de 38 casos.

INTRODUCTION: The incidence of urethritis due to Haemophilus species is increasing. The main aim of this study was to describe the clinical and microbiological characteristics of patients with this form of urethritis. A secondary aim was to discuss the adequacy of treatments in patients with different types of antibiotic resistance. MATERIAL AND METHODS: We studied patients with a microbiologically confirmed diagnosis of urethritis seen at the Sexually Transmitted Infections Unit of our hospital between July 2015 and July 2018. We selected all patients in whom Haemophilus species were isolated on chocolate agar. Antibiotic resistance was tested using the disk-diffusion method. Cross-sectional data were collected prospectively during outpatient visits. RESULTS: Haemophilus species were isolated in 33.6% of cases. The most common clinical manifestation was urethral discharge (57.6%); 60% of the patients were men who have sex with men and in this subgroup Haemophilus species were significantly more common than either Neisseria or Chlamydia species. Haemophilus species were found in isolation in 39.5% of patients and the most common one was Haemophilus parainfluenzae (isolated in 84.2% of cases). In total, 34.2% of patients were resistant to azithromycin and 26.3% were resistant to both azithromycin and tetracycline. Empirical treatment achieved clinical and microbiologic cure in 11 of the patients who were not lost to follow-up (n=17; 44.7%). The remaining 6 patients required treatment with a new antibiotic. CONCLUSIONS: Haemophilus species are a new cause of nongonococcal urethritis, whose incidence is rising, particularly in men who have sex with men who engage in unprotected oral sex. The clinical manifestations are similar to those seen in gonococcal urethritis. Eradication of infection must be confirmed due to the high rate of antibiotic resistance associated with Haemophilus species.