Study of the genetic diversity of Moraxella spp. isolates obtained from corneal abscesses / Estudio de la diversidad genética de aislamientos de Moraxella spp. a partir de abscesos corneales

Abstract This is the first study of the genetic diversity of Moraxella spp. Isolates were detected in an Eye Hospital in the City of Buenos Aires. Due to the high frequency of Moraxella spp. observed in corneal abscesses, we decided to validate their identification at the species level, determine their drug susceptibility and perform molecular subtyping. Seventeen (17) isolates obtained from corneal abscesses were evaluated. The identification was carried out using a combination of biochemical tests and MALDI-TOF mass spectrometry. Of these isolates, 88.2% were identified as Moraxella lacunata, and 11.8% as Moraxella nonliquefaciens. Molecular subtyping was performed using the pulsed-field gel electrophoresis (PFGE) technique. All isolates were typable and thirteen digestion patterns were identified. Based on the obtained results, the PFGE technique using the SmaI enzyme can be used for epidemiological studies of strains of these species.

Resumen En este trabajo se presenta el primer estudio de diversidad genética de aislamientos de Moraxella spp. detectados en un hospital de oftalmología de la Ciudad Autónoma de Buenos Aires. Debido a la observación de una elevada frecuencia de Moraxella spp. en abscesos corneales, se decidió confirmar su identificación a nivel de especie, conocer su sensibilidad y realizar la subtipificación molecular. Se analizaron 17 aislamientos provenientes de abscesos corneales. La identificación se realizó mediante una combinación de pruebas bioquímicas y espectrometría de masas, MALDI-TOF MS. El 88,2% fueron identificados como Moraxella lacunata y el 11,8% como Moraxella nonliquefaciens. La subtipificación molecular se realizó por la técnica de electroforesis en gel de campo pulsado (PFGE). Todos los aislamientos fueron tipificables y se identificaron 13 patrones de digestión. Nuestros resultados muestran que la técnica de PFGE con la enzima SmaI es útil para hacer estudios epidemiológicos en cepas de estas especies.

Research progress on pathogenicity and mechanism of important virulence factors of Moraxella catarrhalis / 中华检验医学杂志

Moraxella catarrhalis ( Mca) is a kind of gram-negative diplococcus which can exist in the respiratory tract of the human. It could be a non-symptom diplococcus on the health people. Otitis media occurs when the Mca reaches the middle ear along the eustachian tube. Sometimes the patients could suffer from the acute exacerbation of chronic obstructive pulmonary disease or pneumonia due to lung lesions caused by Mca. Little is known about the pathogenesis of the Mca, which leads to an incomplete understanding of its pathogenicity. This review aims to clarify the relationships between the Mca and the related diseases and the mechanism of the significant virulence factors. We hope to raise awareness of Mca and also provide some ideas for clinical diagnosis of relevant diseases it caused.

In vitro antibacterial activity of pediatric Faropenem sodium against respiratory tract pathogens in children / 中华实用儿科临床杂志

Objective:To evaluate the antibacterial activity of pediatric Faropenem sodium against common pathogens isolated from children′s respiratory tract in vitro, and to provide reference for its clinical research and application. Methods:Retrospective analysis.The minimum inhibitory concentration (MIC) of Faropenem sodium, Merope-nem, Imipenem and other antibiotics was determined by the agar dilution method.A total of 156 strains of Streptococcus pneumoniae [including 32 strains of Penicillin-susceptible Streptococcus pneumoniae (PSSP), 28 strains of Penicillin-intermediate Streptococcus pneumoniae (PISP) and 96 strains of Penicillin-resistant Streptococcus pneumoniae (PRSP)], 98 strains of Haemophilus influenza, 173 strains of Klebsiella pneumoniae, and 55 strains of Moraxella catarrhali clinical isolates were used.MIC 50, MIC 90 and the accumulative inhibition of the bacteria were investigated. Results:The MIC of Faropenem sodium against all the Streptococcus pneumoniae strains ranged from 0.010-2.000 mg/L.There was no difference in the MIC distribution of Faropenem sodium against PSSP, PISP and PRSP, and the MIC 90 value was all 1.000 mg/L.Faropenem sodium inhibited all the Haemophilus influenza strains at concentrations ranging from 0.030-8.000 mg/L.There was no difference in the MIC distribution of Faropenem sodium against Haemophilus influenza with or without β-lactamase and Ampicillin resistance.The MIC 90 value was all 4.000 mg/L.Ho-wever, the MIC of Faropenem sodium against Klebsiella pneumoniae ranged from 0.250 to above 32.000 mg/L, and both MIC 50 and MIC 90 were greater than 32.000 mg/L.Faropenem sodium inhibited all the Moraxella catarrhalis strains at concentrations ranging from 0.030-2.000 mg/L, with MIC 50 being 0.500 mg/L and MIC 90 being 1.000 mg/L. Conclusions:Antimicrobial susceptibility testing results in vitro demonstrate that pediatric Faropenem sodium has satisfactory antibacterial activities against Streptococcus pneumoniae, Haemophilus influenza, and Moraxella catarrhalis, but comparatively weak antibacterial activities against Klebsiella pneumoniae.

Common bacteria in oropharynx of children with Mycoplasma pneumoniae pneumonia and its clinical significance / 中华实用儿科临床杂志

Objective:To investigate the common bacteria in the oropharynx of children with Mycoplasma pneumoniae pneumonia (MPP) and its clinical significance.Methods:A total of 134 children with MPP who were hospitalized in the Department of Pediatric Respiratory, Shengjing Hospital of China Medical University from December 2016 to June 2017 were selected as the research subjects, and 42 healthy children in the same hospital were selected retrospectively as the healthy control group during the same period.Fluorescent quantitative polymerase chain reaction Taqman probe was used to detect common oropharyngeal bacteria[ Streptococcus pneumoniae(SP), Moraxella catarrhalis(CTA), Haemophilus influenza(HI)] for the enrolled children.Firstly, the bacterial detection rate of MPP children and healthy children was compared.Then, according to age(<1 years old, 1-<3 years old, 3-<6 years old and 6-14 years old), bacterial detection[Mycoplasma pneumoniae(MP), MP+ bacteria]and bacterial species(MP+ SP, MP+ CTA, MP+ HI), 134 children with MPP were divided into groups to compare.Moreover, the relevant clinical datas were retrospectively analyzed by rank sum test and chi- square test. Results:Among 134 children with MPP, 79 (58.96%) children were detected bacteria, and 17 (40.48%) children were detected bacteria among 42 healthy children, with statistically significant differences( χ2=4.404, P<0.05). Compared with the MP group, the level of white blood cell (WBC)[8.5(6.7, 12.0)×10 9/L vs.7.8(5.8, 9.3)×10 9/L, Z=-2.232], C reactive protein(CRP)[19.2(7.2, 35.0) mg/L vs.8.4(3.4, 24.6) mg/L, Z=-2.810], lactate dehydrogenase(LDH)[286(244, 365) U/L vs.250(210, 302) U/L, Z=-2.474] and the incidence of lobar pneumonia[40.51%(32/79 cases) vs.18.18%(10/55 cases), χ2=7.510], pleural effusion[13.92%(11/79 cases) vs.3.64%(2/55 cases), χ2=3.917], refractory Mycoplasma pneumoniae pneumonia (RMPP)[34.18%(27/79 cases) vs.18.18%(10/55 cases), χ2=4.151] in MP+ bacteria group were higher; the course of fever[10(7, 12) d vs.8(6, 10) d, Z=-2.706] and duration of antibiotic use[16(13, 19) d vs.12(9, 16) d, Z=-3.747] in MP+ bacteria group were longer (all P<0.05). The level of WBC in MP+ SP group[12.20(7.80, 17.30)×10 9/L] was higher than that in MP+ HI group [6.75(5.37, 9.44)×10 9/L], and the differences were statistically significant( Z=11.574, P<0.05), and the incidence of lobar pneumonia in MP+ SP group [56.67%(17/30 cases)]was higher than that in MP+ CTA group [0(0/3 cases)]and MP+ HI group[18.75%(3/16 cases)], and the differences were statistically significant( χ2=9.770, P<0.05). Conclusions:Bacterial colonization or infection is more likely to occur in the oropharynx of children with MPP.When WBC, CRP, and LDH are significantly increased and the image shows a large consolidation or pleural effusion, it may indicate mixed bacterial infection, longer course of fever and higher incidence of RMPP, and the common mixed bacteria is SP.

Molecular characterization of bacterial microbiota associated with infectious bovine keratoconjunctivitis in Michoacán, Mexico / Caracterización molecular de la microbiota bacteriana asociada con queratoconjuntivitis infecciosa bovina en Michoacán, México / Caracterização molecular da microbiota bacteriana associada à ceratoconjuntivite bovina infecciosa em Michoacán, México

Abstract Background: The most common ocular disease affecting cattle worldwide is infectious bovine keratoconjunctivitis (IBK), which has been associated with Moraxella bovis bacterium. Objective: To report the molecular characterization of the ocular bacterial microbiota and its relation to IBK in cattle in two dairy regions in Michoacán, Mexico. Methods: A total population of 761 bovines were evaluated, of which 17 (2.23%) showed symptoms of IBK. Thirty-eight bacterial isolates from ocular samples of bovines with IBK were characterized by Gram-staining and antimicrobial sensitivity. In addition, isolates were identified by sequence comparisons of the 16S ribosomal gene. Results: The genus Moraxella was one of the most abundant bacteria and M. bovoculi was the most predominant species. Conclusion: The bacterial isolates identified in eye lesions of cattle and associated to IBK are diverse. To the author´s knowledge, this is the first study on the subject in Mexico; therefore, more research is needed to estimate the incidence of IBK and determine its associated microbiota.

Resumen Antecedentes: la enfermedad ocular más común que afecta al ganado en todo el mundo es la queratoconjuntivitis infecciosa bovina (IBK), que se ha asociado con la bacteria Moraxella bovis. Objetivo: reportar la caracterización molecular de la microbiota bacteriana ocular y su relación con IBK en ganado de dos regiones lecheras en Michoacán, México. Métodos: se evaluó una población total de 761 bovinos de los cuales 17 (2,23%) mostraron síntomas de IBK. Se obtuvieron treinta y ocho aislamientos bacterianos de muestras oculares de bovinos con IBK, los cuales se caracterizaron por tinción de Gram y sensibilidad antimicrobiana. Además, los aislamientos se identificaron mediante comparaciones de secuencias del gen ribosomal 16S. Resultados: el género Moraxella fue una de las bacterias más abundantes y M. bovoculi fue la especie más predominante. Conclusión: los aislamientos bacterianos identificados en lesiones oculares de bovinos y asociados a IBK son diversos. Hasta donde sabemos, este es el primer estudio sobre el tema realizado en México; por lo tanto, es necesario ampliar esta investigación para estimar la incidencia de IBK y determinar la microbiota asociada con la misma.

Resumo Antecedentes: a doença ocular mais comum que afeta o gado no mundo é a ceratoconjuntivite bovina (IBK), que tem sido associada à bactéria Moraxella bovis. Objetivo: relatar a caracterização molecular da microbiota bacteriana ocular e sua relação com a IBK em bovinos de duas regiões leiteiras de Michoacán, México. Métodos: foi avaliada uma população total de 761 bovinos, más apenas 17 (2,23%) apresentaram sintomas de IBK. Trinta e oito isolados bacterianos de amostras de olho bovino com IBK foram caracterizados por coloração de Gram e sensibilidade antimicrobiana. Além disso, os isolados foram identificados por comparação de sequências do gene ribossômico 16S. Resultados: a microbiota bacteriana associada à IBK foi diversa, sendo o gênero Moraxella uma das mais abundantes e M. bovoculi a espécie predominante. Conclusão: de acordo com o conhecimento dos autores, este é o primeiro estudo sobre o tema no México até o momento, portanto é necessário expandir essa pesquisa para estimar a incidência de IBK e determinar a microbiota associada à mesma.

A polycyclic aromatic hydrocarbon degrading strain and its potential of degrading phenanthrene in various enhanced systems / 生物工程学报

Polycyclic aromatic hydrocarbons (PAHs) are a class of common environmental pollutants that pose threats to human health. In this study, a mesophilic bacterial strain CFP312 (grown at 15-37 °C, optimal at 30 °C) was isolated from PAHs-contaminated soil samples. It was identified as Moraxella sp. by morphological observation, physiological and biochemical test, and 16S rRNA gene phylogeny analysis. This is the first reported PAHs degrading strains in Moraxella. Degradation analysis showed that 84% and 90% of the loaded phenanthrene (400 mg/L) were degraded within 48 h and 60 h, and the degradation rates reached 1.21 and 1.29 mg/(L·h), respectively. During the degradation of phenanthrene, phenanthrene-3,4-dihydrodiol was detected as an intermediate. Based on this, it was proposed that double oxygenation at the positions 3 and 4 of phenanthrene was the first step of biodegradation. Adaptability of strain CFP312 to different enhanced phenanthrene-degradation systems was tested in aqueous-organic system, micellar aqueous system, and cloud point system. Strain CFP312 showed good adaptability to different systems. In addition, the bacterium can rapidly degrade the phenanthrene in contaminated soil in slurry-aqueous system, indicating great potential in environmental remediation.

Corneal Collagen Cross-linking for Corneal Ulcer from Moraxella Group

PURPOSE: To report a case of corneal collagen cross-linking for corneal ulcer caused by the Moraxella group.CASE SUMMARY: A 77-year-old male had decreased visual acuity for several days in his right eye. The patient showed severe stromal ring infiltrates with a corneal epithelial defect measuring (5.0 × 7.0 mm), a corneal endothelial plaque, and a hypopyon measuring less than 1.0 mm in height in the anterior chamber of the right eye. There was no abnormal finding in the right eye using B-scan ultrasonography. Before starting treatment, a corneal culture was conducted. The culture tests showed the presence of the Moraxella group. Because the patient was diagnosed with a corneal ulcer caused by the Moraxella group, corneal collagen cross-linking (CXL) was performed. The antimicrobial susceptibility test confirmed that this Moraxella group was sensitive to ceftazidime, so the patient was treated with 5% ceftazidime eye drops and 0.5% moxifloxacin eye drops every 2 hours for 9 months after corneal collagen CXL. The uncorrected visual acuity was 0.1 in the right eye, and there was almost no corneal stromal melting on anterior segment optical coherence tomography.CONCLUSIONS: This is the first known case of a corneal ulcer, in the Republic of Korea, caused by the Moraxella group and treated with corneal collagen CXL. Corneal collagen CXL should be considered as a surgical treatment for patients who have an impending corneal perforation due to a corneal ulcer because it is a simple procedure and causes fewer serious complications than other treatments.

Fulminant scleral abscess secondary to infected scleral buckle with Moraxella species

We here report a case of scleral buckle infection with fulminant scleral abscess secondary to Moraxella species. A 54-year-old chronic alcoholic male with a history of retinal detachment repair, with scleral buckle 8 years prior, presented with complaints of severe pain, redness, and swelling in the right eye since 2 weeks. The patient was diagnosed with scleral buckle infection, the buckle was removed, and cultures revealed Moraxella species. The postoperative course included fulminant scleral abscess treated with dual antibiotic therapy that included ceftriaxone and moxifloxacin. All systemic antibiotics were discontinued after 3 weeks, retina remained attached, and no recurrence occurred over a 1-year follow-up. Moraxella, though commonly associated with bacterial keratitis, can also lead to buckle infection, especially in chronic alcoholic and immunocompromised patients. In buckle infection, infected buckle along with sutures should be immediately removed without damaging underlying compromised sclera. Lastly, culture and drug sensitivity play a very important role in buckle infections.

Bacteremia due to Moraxella osloensis: a case report and literature review

ABSTRACT Herein we report the case of a 10-year-old boy with an autosomal mosaic mutation who developed bacteremia. The causative agent was identified as Moraxella osloensis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene sequencing. In the pediatric population, there have been 13 case reports of infection attributed to M. osloensis and this is the fifth reported case of pediatric bacteremia due to M. osloensis. After Moraxella species infection was confirmed, the patient recovered with appropriate antimicrobial therapy. It is important to consider that M. osloensis can cause serious infections, such as bacteremia, in otherwise healthy children.

Marcadores moleculares de tipo inserción en bacterias de las familias Moraxellaceae y Helicobacteraceae (phylum Proteobacteria) / Molecular markers of insertion type in bacterias of the Moraxellaceae and Helicobacteraceae (phylum Proteobacteria) families

Se efectuó un estudio con el empleo de la metodología de Gupta, en el Departamento de Biología y Geografía de la Universidad de Oriente en Santiago de Cuba, para determinar marcadores moleculares de tipo inserción en secuencias de las proteínas ADN polimerasa I y ADN polimerasa III (subunidad alfa), obtenidas de bases de datos internacionales y posteriormente alineadas con el programa ClustalX2. Las familias Moraxellaceae y Helicobacteraceae han sido ampliamente estudiadas, porque comprenden agentes patógenos causantes de numerosas enfermedades en humanos, pero pocas investigaciones han estado dirigidas a la identificación de las características moleculares que puedan distinguir a sus miembros de otros grupos de bacterias; de manera que los presentes resultados constituyen un aporte al conocimiento de la genética y la bioquímica de estas familias y proveen herramientas moleculares para la clasificación taxonómica y el diagnóstico de especies patógenas

A study with the use of Gupta methodology was carried out in the Biology and Geography Department of Oriente University in Santiago de Cuba, to determine molecular markers of insertion type in sequences of the DNA polimerase I proteins and DNA polimerase III (alpha subunity), obtained from international databases and later on aligned with the ClustalX2 program. The Moraxellaceae and Helicobacteraceae families have been broadly studied, because they comprise pathogen agents that cause numerous diseases in humans, but few investigations have been directed to the identification of the molecular characteristics that can distinguish their members from other groups of bacterias; so these results constitute a contribution to the knowledge of genetics and biochemistry of these families and provide molecular tools for the taxonomic classification and the diagnosis of pathogen species

Serotype distribution and drug resistance of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis isolated from nasopharynx of Uygur children / 中华儿科杂志

Objective@#To investigate the serotype distribution and antimicrobial susceptibility pattern of Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae) and Moraxella catarrhalis (M. catarrhalis) isolates collected from nasopharyngeal swabs from Uygur children in Kashi.@*Methods@#Nasopharyngeal swabs were collected from inpatient Uygur children aged from 1 month to 5 years with respiratory infections from the pediatric department, the First People's Hospital of Kashi, Xinjiang Uygur Autonomous Region. Antimicrobial susceptibilities of the isolates were determined with E-test and KB disk diffusion methods. The production of β-lactamase was detected for H. influenzae and M. catarrhalisisolates using nitrocefin disc method. Quellung test and latex agglutination test were adopted to identify serotypes of S. pneumoniae and H. influenzae isolates.@*Results@#Forty-seven S. pneumoniae, 13 H. influenzae and 16 M. catarrhalis isolates were detected. All of the 47 S. pneumoniae isolates were sensitive to parenteral penicillin, amoxicillin-clavulanic acid, vancomycin and levofloxacin; the susceptibility rates to cefotaxime, imipenem and chloramphenicol were 94% (44/47), 89% (42/47), and 98% (46/47). The resistance rate to erythromycin was 74% (35/47). The most common serotype of S. pneumoniae was serotype 19A (10 strains, 21%). The coverage rate of 13-valent conjugate vaccine (PCV13) was 70% (33/47). None of the 13 H. influenzae isolates could be typed. They were highly susceptible to tested β-lactams antibiotics, except ampicillin. Only one H. influenzae isolate could produce β-lactamase, and two isolates were identified as β-lactamase-negative-ampicillin-resistant ones. The sixteen M. catarrhalis isolates were all positive in β-lactamase detection, but sensitive to amoxicillin-clavulanic acid, cephalosporins and meropenem.@*Conclusions@#In Kashi, Xinjiang Uygur Autonmous Region, S. pneumoniae isolates from Uygur children were highly sensitive to parenteral penicillin and other β-lactams antibiotics. H. influenzae isolates from Uygur children were highly susceptible to amoxicillin-clavulanic acid, cephalosporins and ciprofloxacin. All M. catarrhalis isolates from Uygur children could produce β-lactamase, but were sensitive to the enzyme inhibitors and cephalosporins.

Antibiotic Resistance Analysis of Haemophilus Influenzae and Moraxella Catarrhalis Strains Isolated from Children in Sichuan Province from 2013 To 2016 / 现代检验医学杂志

Objective To investigate the changing antibiotic resistance profile of Haemophilus influenzae and Moraxella catarrhalis strains collected from children in Sichuan province from 2013 to 2016,provide some reference for rational utilization of clinical antimicrobial agents.Methods Collected the infection data of Haemophilus influenzae and Moraxella catarrhalis strains isolated from children which reported in Sichuan Province Drug Resistance Monitoring Report from 2013 to 2016.The experimental results were analyzed by WHONET5.6 software.Results The prevalence of H.influenzae increased with time from 8.95％ in 2013 to 16.6％ in 2016.The prevalence of M.catarrrhalis increased with time from 4.16％ in 2013 to 6.34％ in 2016.Among the 15 896 clinical strains of H.influenzae,the highest resistance rate was to ampicillin,which was 71.6％ in 2016.The resistance rate to cefaclor also increased from 26.1％ in 2013 to 59.5％ in 2016 for increase of 33.4％.The insensitivity rate to azithromycin increased from 8.3％ in 2013 to 25％ in 2016.However,the insensitivity rate to ceftriaxone and moxifloxacin decreased in recent years and the susceptibility rate to ceftriaxone,cefotaxime,levofloxacin and moxifloxacin were higher than 90％ in each year.The resistance rate of H.influenzae strains from children were higher than the stains from all patients.The insensitivity rate to azithromycin in strains from children and all patients increased from 8.3％,10.2％ in 2013 to 25％,22.1 ％ in 2016,respectively.The 5 625 clinical strains of M.catarrrhalis re mained highly susceptible to the amoxicillin-clavulanic acid,ceftriaxone,cefotaxime,levofloxacin,ciprofloxacin (greater than 90％).The resistance rate to cotrimoxazole increased from 15.1 ％ in 2013 to 59.1 ％ in 2016.Conclusion H.influenzae are still susceptible to the third generation cephalosporins (greater than 90 ％),which can be used as the first choice in clinical practice.Nearly 70 ％ of these strains were resistant to ampicillin and cotrimoxazole,which is inappropriate for clinical therapy.The resistance rate to cotrimoxazole in the M.catarrrhalis strains from children increased from 15.1％ in 2013 to 59.1 ％ in 2016,and the resistance rate to the other test drug in M.catarrrhalis did not change much in the-year period.

Preparation and identification of polyclonal antibodies against Moraxella catarrhalis UspA1 / 生物工程学报

To prepare polyclonal antibodies (PcAb) against UspA1 of Moraxella catarrhalis (Mc), we used bioinformatic analysis to determine the surface exposed region in this protein that holds the antigen epitopes. Then the corresponding coding sequences for this fragment was artificially synthesized according to the codon usage of Escherichia coli. The gene fragment was then subcloned into the prokaryotic expression vector pET-28a(+) and expressed in E. coli rosseta (DE3), and then the recombinant UspA1-His proteins were purified. Two New Zealand white rabbits were immunized with this protein to prepare antiserum. The resulting PcAb was then purified from the antiserum with Protein A affinity column. The results of fluorescence antibody assay, enzyme linked immunosorbent assay and Western blotting analysis showed that the PcAb could specifically recognize the surface exposed region of UspA1 on Mc. The preparation of the PcAb laid a foundation of further development of rapid detection technique for M. catarrhalis.

Development of real-time fluorescence quantitative PCR for the detection of Moraxella catarrhalis / 国际儿科学杂志

Objective To developed A laboratory diagnosis of Moraxella catarrhalis by an laboratories diagnostic method real-time fluorescence quantitative PCR assay. Methods The specific primers and probes were designed based on the sequence of outer membrane protein CopB(copB)gene in Moraxella catarrhalis,and the Taqman probe RT-PCR method was developed to detect the Moraxella catarrhalis.The standard plasmids ex-tracted from the Moraxella catarrhalis standard strains were used to constitute the standard samples,and compared with these standard samples,the sensitivity of the fluorescence quantitative PCR assay was tested by the estab-lished standard curves.The specificity of the fluorescence quantitative PCR assay was tested by the DNA samples of other bacterias in the laboratory.Meanwhile,321 throat swab samples from inpatient and outpatient child pa-tients,with asthma infection were collected as clinical samples to validate the fluorescence quantitative PCR as-say.Results The standard curve was drawn in the real-time PCR by the Taqman fluorescence reporter.During the sensitivity tests,the newly-developed real-time fluorescence PCR could detect at least 10 copies of Moraxella catarrhalis,and could successfully distinguish several DNAs of the pathogens.On the basis of the validation result of the 321 throat swab samples,there are 25 Moraxella catarrhalis with 7.79 % positive rate.Conclusion The fluorescence quantitative PCR assay is of great sensitivity and specificity,and it can be widely used for the detec-tion of Moraxella catarrhalis.

Isolation and identification of Moraxella cuniculi from a rabbit with keratoconjunctivitis

A Gram-negative, catalase- and oxidase-positive, coccus-shaped bacterium was isolated from a rabbit with keratoconjunctivitis. Colonies of the isolate were round, smooth, and exhibited hemolytic activity on 5% sheep blood agar. Scanning electron microscopy revealed 0.4 to 0.5 µm diameter oval cocci. Partial 16S rRNA gene (1446 bp) sequence analysis demonstrated the isolate had significant homology with the Moraxella cuniculi CCUG2154 strain isolated from a rabbit in Germany in 1973. Our isolate was designated as APQAB1701. Antibiotic susceptibility tests demonstrated that APQAB1701 was sensitive to 24 antibiotics; 3 of the antibiotics (nalidixic acid, spectinomycin, and colistin) had minimal inhibitory concentrations ≥ 32 µg/mL against the isolate.

Antibiograma y Prevalencia de Moraxella catarrhalis en el laboratorio "Instituto de Patología" Cochabamba 2005-2010 / Antibiogram and Prevalence of Moraxella catarrhalis in the "Institute of Pathology" Cochabamba 2005-2010

Moraxella catarrhalis es un diplococo Gram negativo, reconocido como miembro de la flora normal, en los últimos 20 años ha emergido como un importante patógeno causante de infecciones en el tracto respiratorio superior e inferior. Verificándose el mayor número de casos en los meses de junio, julio y diciembre a marzo, además de tener una sensibilidad a antimicrobianos como Gentamicina, Ciprofloxacina, Cloranfenicol y Amoxicilina-Acido Clavulánico. El objetivo de este estudio es determinar la prevalencia de Moraxella catarrhalis en aparato respiratorio, según edad, el tipo de muestra, además de su sensibilidad y resistencia a los antibióticos, durante la gestión 2005-2010. Estudio descriptivo, de corte transversal y retrospectivo, con universo de 67 muestras de cultivo bacteriano de vías respiratorias alta y baja, que acudieron al laboratorio, con sus respectivos antibiogramas. Se cuantificaron 39 muestras de esputo e hisopado faríngeo de los aislamientos de Moraxella catarrhalis registrados en laboratorio.

Moraxella catarrhalis is a gram-negative Diplococcus, recognized as a member of the normal flora, in the last 20 years has emerged as an important pathogen causing infections in the upper and lower respiratory tract. Showing a mayor number of cases in June, July and December to March, also has a sensitivity to some antibiotic such as Gentamicina, Ciproflaxacin, Chloramphenicol and Amoxicillin-Clavulonic acid.The objective of this study is to determine the prevalence of Moraxella catarrhalis in respiratory system, according to age, type of sample; sensitivity and antibiotic resistance during 2005 - 2010. Descriptive, transversal, retrospective study with a universe of 67 samples of microbiological culture and sensitivity from high and low airway was performed from people who came to the laboratory. Sputum samples and 39 throat swab isolates of Moraxella catarrhalis were quantified.

β-Lactamase production and antimicrobial susceptibility pattern of Moraxella catarrhalis isolates: Report from Pakistan

Objective: To assess the frequency of β-lactamase production and antimicrobial resistance in Moraxella catarrhalis isolated from clinical specimens in Pakistan. Methods: This cross sectional study (January to December 2010) was conducted in clinical microbiology laboratory of Aga Khan University Hospital. A total of 97 clinical respiratory specimens growing Moraxella catarrhalis were included. Frequency of β-lactamase production and antimicrobial resistance rates against ampicillin, erythromycin, ciprofloxacin and tetracycline were noted by performing minimum inhibitory concentration (MIC). MICs were calculated as MIC

β-Lactamase production and antimicrobial susceptibility pattern of Moraxella catarrhalis isolates: report from Pakistan

OBJECTIVE@#To assess the frequency of β-lactamase production and antimicrobial resistance in Moraxella catarrhalis isolated from clinical specimens in Pakistan.@*METHODS@#This cross sectional study (January to December 2010) was conducted in clinical microbiology laboratory of Aga Khan University Hospital. A total of 97 clinical respiratory specimens growing Moraxella catarrhalis were included. Frequency of β-lactamase production and antimicrobial resistance rates against ampicillin, erythromycin, ciprofloxacin and tetracycline were noted by performing minimum inhibitory concentration (MIC). MICs were calculated as MIC50 and MIC90.@*RESULTS@#β-Lactamase production was detected in 84% of isolates, which correlated well with high MIC of ampicillin. Majority of isolates were susceptible to erythromycin (97%) and tetracycline (96%) with MIC90=0.12 mg/L and MIC90=1 mg/L respectively. All isolates were found susceptible to ciprofloxacin (MIC90=0.06 mg/L).@*CONCLUSIONS@#Result suggests that empirical use of ampicillin should be discouraged while treating respiratory tract infections. This also emphasizes the importance of continuous surveillance in order to detect emerging resistance in Moraxella isolates.

The relationship between meteorological parameters and the prevalence of Moraxella catarrhalis infection in chil-dren hospitalized with acute respiratory infection in Suzhou / 临床儿科杂志

Objective To explore the correlation of meteorological parameters with the epidemic of acute Moraxella ca-tarrhalis respiratory infection in hospitalized children in Suzhou. Methods A total of 8143 children with acute respiratory infec-tion were participated in the trial during 2006 to 2010, and the secretions of nasopharynx were collected for bacterium culture. Moraxella catarrhalis was identified according to the routine technique of culture. Meteorological parameters including mean temperature, relative humidity, rainfall amount, duration of sunshine and mean wind velocity were collected monthly during the same period. The relationship between the epidemic of Moraxella catarrhalis and metrorological parameters were analyzed by seasonal decomposition method, the Spearman rank correlation and stepwise regression analysis. Results Moraxella catarrhalis was identified in 4.04% of 8 143 specimens. The prevalence of acute Moraxella catarrhalis respiratory infection was higher during winter and spring. The monthly infection rate of Moraxella catarrhalis was negatively correlated with mean temperature as well as duration of sunshine and wind velocity. Wind velocity was independent risk factor for Moraxella catarrhalis infection. Conclusions Moraxella catarrhalis is a primary pathogen in respiratory tract infection in children in Suzhou. The epidemic of Moraxella catarrhalis is closely related to meteorological parameters.

Antimicrobial resistance and BRO genotyping of Moraxella catarrhalis isolates from respiratory tract in children / 临床儿科杂志

Objectives To investigate antimicrobial resistance and beta-lactamase production of Moraxella catarrhalis isolates from respiratory tract in children and to understand the characteristics of BRO beta-lactamase gene. Methods From June 2011 to Sep-tember 2012, 401 Moraxella catarrhalis isolates were obtained from respiratory tract in children. Minimum inhibitory concentrations (MIC) of commonly-used antibiotics were determined by microbroth dilution assay, and beta-lactamase production was detected by Nitroceifn disk test. PCR combining restriction endonuclease analysis was employed to do the BRO genotyping. Results 96.5%iso-lates were beta-lactamase positive (387/401), MIC (MIC50/MIC90) values and resistant rates of beta-lactamase producing isolates were higher than those of non beta-lactamase producing isolates for ampicillin, cefaclor and cefuroxime (P<0.05). The positive rate of BRO gene was 99.2%in beta-lactamase producing isolates (384/387), consisting of 93.0%BRO-1 isolates and 7.0%BRO-2 isolates. MIC50 and MIC90 values of BRO-1+isolates were higher than those of BRO-2+isolates for ampicillin, cefaclor, cefuroxime and azithromycin. Conclusions The beta-lactamase production rate is high in Moraxella catarrhalis isolates from respiratory tract in children. BRO-1 type was the dominant genotype of beta-lactamase producing isolates, having more inlfuence than BRO-2 type in the inlfuence on some beta-lactams and macrolides.