Antibodies mediate formation of neutrophil extracellular traps in the middle ear and facilitate secondary pneumococcal otitis media

Otitis media (OM) (a middle ear infection) is a common childhood illness that can leave some children with permanent hearing loss. OM can arise following infection with a variety of different pathogens, including a coinfection with influenza A virus (IAV) and Streptococcus pneumoniae (the pneumococcus). We and others have demonstrated that coinfection with IAV facilitates the replication of pneumococci in the middle ear. Specifically, we used a mouse model of OM to show that IAV facilitates the outgrowth of S. pneumoniae in the middle ear by inducing middle ear inflammation. Here, we seek to understand how the host inflammatory response facilitates bacterial outgrowth in the middle ear. Using B cell-deficient infant mice, we show that antibodies play a crucial role in facilitating pneumococcal replication. We subsequently show that this is due to antibody-dependent neutrophil extracellular trap (NET) formation in the middle ear, which, instead of clearing the infection, allows the bacteria to replicate. We further demonstrate the importance of these NETs as a potential therapeutic target through the transtympanic administration of a DNase, which effectively reduces the bacterial load in the middle ear. Taken together, these data provide novel insight into how pneumococci are able to replicate in the middle ear cavity and induce disease.

A multi-centre open-label randomised non-inferiority trial comparing watchful waiting to antibiotic treatment for acute otitis media without perforation in low-risk urban Aboriginal and Torres Strait Islander children (the WATCH trial): study protocol for a randomised controlled trial

Background Treatment guidelines recommend watchful waiting for children older than 2 years with acute otitis media (AOM) without perforation, unless they are at high risk of complications. The high prevalence of chronic suppurative otitis media (CSOM) in remote Aboriginal and Torres Strait Islander communities leads these children to be classified as high risk. Urban Aboriginal and Torres Strait Islander children are at lower risk of complications, but evidence to support the subsequent recommendation for watchful waiting in this population is lacking. Methods/Design This non-inferiority multi-centre randomised controlled trial will determine whether watchful waiting is non-inferior to immediate antibiotics for urban Aboriginal and Torres Strait Islander children with AOM without perforation. Children aged 2 − 16 years with AOM who are considered at low risk for complications will be recruited from six participating urban primary health care services across Australia. We will obtain informed consent from each participant or their guardian. The primary outcome is clinical resolution on day 7 (no pain, no fever of at least 38 °C, no bulging eardrum and no complications of AOM such as perforation or mastoiditis) as assessed by general practitioners or nurse practitioners. Participants and outcome assessors will not be blinded to treatment. With a sample size of 198 children in each arm, we have 80 % power to detect a non-inferiority margin of up to 10 % at a significance level of 5 %, assuming clinical improvement of at least 80 % in both groups. Allowing for a 20 % dropout rate, we aim to recruit 495 children. We will analyse both by intention-to-treat and per protocol. We will assess the cost- effectiveness of watchful waiting compared to immediate antibiotic prescription. We will also report on the implementation of the trial from the perspectives of parents/carers, health professionals and researchers. Discussion The trial will provide evidence for the safety and effectiveness of watchful waiting for the management of AOM in Aboriginal and Torres Strait Islander children living in urban settings who are considered to be at low risk of complications.

Childhood otitis media - risk factors and surgical management

Background: Otitis media (OM) is one of the most common childhood diseases. Approximately every third child suffers from recurrent acute otitis media (RAOM), and 5% of all children have persistent middle ear effusion for months during their childhood. Despite numerous studies on the prevention and treatment of OM during the past decades, its management remains challenging and controversial. In this study, the effect of adenoidectomy on the risk for OM, the potential risk factors influencing the development of OM and the frequency of asthma among otitis-prone children were investigated. Subjects and methods: One prospective randomized trial and two retrospective studies were conducted. In the prospective trial, 217 children with RAOM or chronic otitis media with effusion (COME) were randomized to have tympanostomy with or without adenoidectomy. The age of the children at recruitment was between 1 and 4 years. RAOM was defined as having at least 3 episodes of AOM during the last 6 months or at least 5 episodes of AOM during the last 12 months. COME was defined as having persistent middle ear effusion for 2-3 months. The children were followed up for one year. In the first retrospective study, the frequency of childhood infections and allergy was evaluated by a questionnaire among 819 individuals. In the second retrospective study, data of asthma diagnosis were analysed from hospital discharge records of 1616 children who underwent adenoidectomy or had probing of the nasolacrimal duct. Results: In the prospective randomized study, adenoidectomy had no beneficial effect on the prevention of subsequent episodes of AOM. Parental smoking was found to be a significant risk factor for OM even after the insertion of tympanostomy tubes. The frequencies of exposure to tobacco smoke and day-care attendance at the time of randomization were similar among children with RAOM and COME. However, the frequencies of allergy to animal dust and pollen and parental asthma were lower among children with COME than those with RAOM. The questionnaire survey and the hospital discharge data revealed that children who had frequent episodes of OM had an increased risk for asthma. Conclusions: The first surgical intervention to treat an otitis-prone child younger than 4 years should not include adenoidectomy. Interventions to stop parental smoking could significantly reduce the risk for childhood RAOM. Whether an otitis-prone child develops COME or RAOM, seems to be influenced by genetic predisposition more strongly than by environmental risk factors. Children who suffer from repeated upper respiratory tract infections, like OM, may be at increased risk for developing asthma.

Dynamics of Streptococcus pneumoniae Serotypes Causing Acute Otitis Media Isolated from Children with Spontaneous Middle-Ear Drainage over a 12-Year Period (1999–2010) in a Region of Northern Spain

10 p.

Detección por PCR multiplexde pseudomonas aeruginosa, proteus mirabilis y malassezia SPP. en caninos con otitis externa.

Tesis (Maestría en Ciencia Animal) UANL, 2011.

Detección por PCR multiplex de pseudomonas aeruginosa, proteus mirabilis y malassezia SPP en caninos con otitis externa.

Tesis (Maestría en Ciencia Animal) UANL, 2011.

Evaluación de factores de riesgo y predisponentes de otitis media en niños expuestos y no a congregarse

Tesis (Doctorado en Medicina)

Chronic Suppurative Otitis Media in Cleft Palate: Microorganism Etiology and Susceptibilities

Objective: To investigate the microbial etiology of suppurative chronic otitis media (SCOM) in patients with complete cleft lip and palate and isolated cleft palate and to determine the sensitivity of isolated microorganisms to antibiotics by drug diffusion from impregnated discs in agar and the minimum inhibitory concentration of each drug to these microorganisms by drug dilution in agar. Design/Patients: Effusion samples of SCOM obtained from 40 patients with cleft lip and palate registered at the Hospital for Rehabilitation of Craniofacial Anomalies, University of Sao Paulo, at Bauru, Brazil, were bacteriologically analyzed by cultures. The isolated bacteria were submitted to an in vitro susceptibility test to clinically used drugs. Results: Positive cultures were obtained in 100% of studied cases. Among the 57 strains observed, the most frequent were Pseudomonas aeruginosa (35%), Staphylococcus aureus (15.5%), Enterococcus faecalis (14%), and Proteus mirabilis (12%). The frequency of Gram-negative bacilli (enterobacteriaceae and nonfermentative bacilli) was 67%. Pseudomonas aeruginosa presented the highest sensitivity to ciprofloxacin, and enterobacteriaceae exhibited the highest sensitivity to gentamicin. The strains of S. aureus and E. faecalis presented the highest sensitivity to imipenem and sulfamethoxazole/trimethoprim, respectively. Conclusion: Patients with cleft lip and palate presenting with SCOM exhibited 100% positive cultures, with the highest frequency of Pseudomonas and enterobacteriaceae. With regard to the action of antibiotics, imipenem was effective against the four species of isolated microorganisms, followed by ciprofloxacin, which was effective against 75% of isolated species.

Isolation of Malassezia pachydermatis and M. sympodialis from the external ear canal of cats with and without otitis externa

The objective of this study was to determine the presence of Malassezia spp. in the external ear canal of cats with and without otitis. Forty-five animals were studied, 20 with and 25 without otitis externa (OE). Cerumen or secretion from external ear canal samples was cultured on modified Mycosel agar and sterile olive oil was added to the surface of the medium before specimen seeding. The isolates were analysed for macro- and micromorphology and identified by catalase tests and on the basis of growth on Tween 20, 40, 60 and 80. Malassezia spp. were isolated from 15 out of 20 (75%) animals with otitis and from 7 out of 25 (28%) cats without OE; the difference between the two groups was statistically significant (P <= 0.05). Malassezia pachydermatis and M. sympodialis were isolated from 60% (12/20) and 40% (8/20) of cats with otitis, respectively, with no significant difference in the frequency of isolation between the two species. In the microflora of the healthy ear canal M pachydermatis was significantly more common (6/25, 24%) than M sympodialis (1/25, 4%). The present investigation confirms that M sympodialis can also act as an actiological agent of feline OE, and if commercial veterinary laboratories do not use media with added lipids for the isolation of Malassezia spp., this might lead to false-negative results.

Chronic Suppurative Otitis Media in Cleft Palate: Microorganism Etiology and Susceptibilities

Objective: To investigate the microbial etiology of suppurative chronic otitis media (SCOM) in patients with complete cleft lip and palate and isolated cleft palate and to determine the sensitivity of isolated microorganisms to antibiotics by drug diffusion from impregnated discs in agar and the minimum inhibitory concentration of each drug to these microorganisms by drug dilution in agar.Design/Patients: Effusion samples of SCOM obtained from 40 patients with cleft lip and palate registered at the Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, at Bauru, Brazil, were bacteriologically analyzed by cultures. The isolated bacteria were submitted to an in vitro susceptibility test to clinically used drugs.Results: Positive cultures were obtained in 100% of studied cases. Among the 57 strains observed, the most frequent were Pseudomonas aeruginosa (35%), Staphylococcus aureus (15.5%), Enterococcus faecalis (14%), and Proteus mirabilis (12%). The frequency of Gram-negative bacilli (enterobacteriaceae and nonfermentative bacilli) was 67%. Pseudomonas aeruginosa presented the highest sensitivity to ciprofloxacin, and enterobacteriaceae exhibited the highest sensitivity to gentamicin. The strains of S. aureus and E. faecalis presented the highest sensitivity to imipenem and sulfamethoxazole/trimethoprim, respectively.Conclusion: Patients with cleft lip and palate presenting with SCOM exhibited 100% positive cultures, with the highest frequency of Pseudomonas and enterobacteriaceae. With regard to the action of antibiotics, imipenem was effective against the four species of isolated microorganisms, followed by ciprofloxacin, which was effective against 75% of isolated species.