Moraxella keratitis: epidemiology and outcomes.

We aimed to assess the prevalence, risk factors, and visual outcome of Moraxella keratitis. We retrospectively reviewed the medical charts of patients diagnosed with Moraxella spp. keratitis at the Quinze-Vingts National Ophthalmology Hospital, Paris, France, between January 2016 and December 2018. Definitive microbiological identification was performed on archival strains using matrix-assisted laser desorption ionization time of flight coupled to mass spectrometry. One hundred one culture-proven cases of Moraxella keratitis were identified. The most common isolates were Moraxella lacunata (50%) and Moraxella nonliquefasciens (38%). Systemic predisposing factors, principally diabetes mellitus (13%) were identified in 28% of patients, and 87% of patients had ocular surface conditions, including blepharitis (25%), prior ocular surgery (21%), glaucoma (17%), exposure keratopathy (16%), and trauma (16%). Severely affected inpatients were treated empirically with fortified antibiotics including vancomycin, piperacillin, and gentamicin. The presence of hypopyon and being over the age of 60 years were associated with a poorer final visual acuity (p < 0.05). Adjuvant treatment, mostly amniotic membrane transplantation, was required for 31 eyes. The prognostic factors significantly associated with the need for adjuvant treatment were a larger infiltrate and hypoesthesia. The clinical features including ulcer healing, treatment duration, and infiltrate size were not different between Moraxella species. Keratitis caused by Moraxella spp. are rare in France but may threaten sight. The early identification of patients with a poor ocular surface, particularly those with neurotrophic keratopathy and anesthetic cornea, is crucial to prevent delayed healing of ulcers and the need for adjuvant treatment.

Profiling the Membrane and Glycosaminoglycan-Binding Proteomes of Moraxella catarrhalis.

Moraxella catarrhalis, a Gram-negative bacterium, is an important respiratory pathogen causing acute otitis media and exacerbations of chronic obstructive pulmonary disease. Adhesion of the pathogen to human epithelial cells is mediated via bacterial membrane adhesin proteins. To identify the surface proteome of Moraxella catarrhalis, we applied different membrane protein extraction methods in combination with different proteomic technologies. Proteins from preparations of outer membrane vesicles and from carbonate extractions were analyzed using either a gel-based nano-HPLC-MS/MS technique or 2D-LC-MS/MS. Furthermore, because glycosaminoglycans (GAGs) play an important role for microbial entry into human cells, the GAG-binding membranome of Moraxella catarrhalis was investigated using a glycan-based pull-down approach. By these means, potential vaccine protein candidates that were previously selected by the ANTIGENome technology were confirmed, but importantly also novel proteins were identified as candidates.

[A rare case of endocarditis due to Moraxella catarrhalis in an immunocompetent patient]. / Nadir görülen bir olgu: immün kompetan bir hastada Moraxella catarrhalis'e bagli endokardit.

Moraxella catarrhalis is a gram-negative, catalase and oxidase positive diplococcus. While it causes otitis media, sinusitis, bronchitis and conjunctivitis in children and adults, it has a tendency to cause lower respiratory tract infections in older ages. More severe clinical pictures with the range of sepsis to endocarditis are also seen in immunocompromised patients. In this report, a case of M. catarrhalis endocarditis in an immunocompetent host who needed valve replacement has been presented. Forty three years old female patient was admitted to our hospital with the complaints of fever, nausea, night sweating and arthralgia for 20 days. Physical examination revealed systolic murmurs on the apex, and vegetation on the atrial surface of mitral valve was detected by transthoracic echocardiography. Intravenous (IV) ampicillin (4 x 3 g/day) and gentamicin (3 x 80 mg/day) treatment was started empirically with prediagnosis of infective endocarditis. The treatment was modified to IV ceftriaxone (1 x 2 g/day) and gentamicin (3 x 80 mg/day) due to the reporting of gram-negative bacilli in blood culture (BacT/ALERT 3D, bioMérieux, France) on the next day. Gram-negative cocobacilli/diplococci were detected with Gram stain on the smear prepared from the blood culture bottle. Simultaneous subcultures to blood agar and eosin methylene blue agar yielded white colored, S-type, non-hemolytic colonies on only blood agar. Catalase and oxidase tests were positive, while beta-lactamase activity was negative. The isolate was identified as M. catarrhalis by using API NH (bioMérieux, France) identification strips. M. catarrhalis was isolated from five different blood culture specimens of the patient. The focus for bacteremia could not be detected. The patient underwent mitral valve replacement operation as an emergency since the vegetation exhibited rapid growth on the fifth day of medical treatment. Antibacterial therapy was completed for 6 weeks. Control echocardiography revealed that artificial mitral valve was open and functional, thus the patient recovered completely without sequela. In conclusion, M. catarrhalis should be considered as a possible cause of infective endocarditis even in immunocompetent patients.

Clinical and microbiological characteristics of Moraxella keratitis.

BACKGROUND/AIMS: To describe the risk factors, clinical features, bacterial subspecies characteristics and treatment outcomes of Moraxella keratitis in a single centre. METHODS: A retrospective review of all patients diagnosed with Moraxella keratitis between November 2012 and December 2017 at the Royal Victoria Eye and Ear Hospital, Dublin, Ireland was performed. Matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry was used to identify Moraxella subspecies. RESULTS: Forty-one cases of Moraxella keratitis were identified. Previous ocular surgery and diabetes were the most common local and systemic risk factors. The most common appearance on presentation was an oval-shaped paracentral infiltrate with a mean diameter of 4.2 mm. Mean presenting and final logarithm of minimal angle of resolution visual acuity were 1.307±0.74 and 0.99±1.01, respectively. Surgical procedures, including penetrating keratoplasty, corneal glueing or evisceration, were required to manage nine (22%) patients. Mean time to complete corneal epithelialisation was 32 (range, 7-109) days and mean duration of topical antibiotic therapy was 54 (range, 9-124) days. MALDI-TOF analysis revealed the following Moraxella subspecies: nonliquifaciens (16; 39%), lacunata (15; 36%), osloensis (4; 10%) and catarrhalis (2; 5%). In four cases (10%), subspecies analysis was inconclusive. M.nonliquifaciens and M. lacunata were associated with larger infiltrates on presentation (p<0.05), required more surgical intervention and longer treatment duration (p<0.001). CONCLUSION: In this large series of patients from Ireland, Moraxella keratitis was notable for its severity on presentation, slow response to antimicrobial therapy, high risk of surgical intervention and poor visual outcome. We have demonstrated the value of subspecies identification using MALDI-TOF by reporting significant differences in the clinical features and prognosis of M. nonliquifaciens and M. lacunata compared with other subspecies.

Moraxella keratitis: predisposing factors and clinical review of 95 cases.

AIM: To analyse the clinical presentation, identify predisposing risk factors and evaluate the outcome of treatment of Moraxella keratitis. METHODS: A retrospective analysis was carried out of culture-proved cases of Moraxella keratitis from hospital records during a 10-year period (from December 1995 to November 2005) at the Corneal Unit of the Royal Victorian Eye and Ear Hospital, Melbourne, Australia. RESULTS: 95 episodes of Moraxella keratitis were identified in 92 patients. 3 (3.2%) patients had recurrent keratitis. The mean age of the patients was 70 (range 17-93) years. Multiple predisposing factors were identified in 23 (24%) eyes, including corneal graft (n = 15), previous herpes keratitis (n = 15) and eye lid diseases (n = 15). Adjunctive procedures were carried out in 42 eyes. These included botulinum toxin injection (n = 17), tarsorraphy (n = 12), penetrating keratoplasty (n = 8), enucleation (n = 3), tissue adhesive and bandage contact lens (n = 4), and conjunctival flap (n = 5). Polymicrobial infection was present in 17 eyes. Final visual acuity was counting finger or less in 25 (26%) eyes. CONCLUSIONS: Local ocular predisposing factors play a major role in Moraxella keratitis. This infection has a poor visual outcome attributable to both the nature of the infection and the predisposing factors.

Efficacy of Bdellovibrio bacteriovorus 109J for the treatment of dairy calves with experimentally induced infectious bovine keratoconjunctivitis.

OBJECTIVE To determine the efficacy of Bdellovibrio bacteriovorus 109J for the treatment of calves with experimentally induced infectious bovine keratoconjunctivitis (IBK). ANIMALS 12 healthy dairy calves. PROCEDURES For each calf, a grid keratotomy was performed on both eyes immediately before inoculation with Moraxella bovis hemolytic strain Epp63-300 (n = 11 calves) or nonhemolytic strain 12040577 (1 calf). For each calf inoculated with M bovis Epp63-300, the eyes were randomly assigned to receive an artificial tear solution with (treatment group) or without (control group) lyophilized B bacteriovorus 109J. Six doses of the assigned treatment (0.2 mL/eye, topically, q 48 h) were administered to each eye. On nontreatment days, eyes were assessed and corneal swab specimens and tear samples were collected for bacterial culture. Calves were euthanized 12 days after M bovis inoculation. The eyes were harvested for gross and histologic evaluation and bacterial culture. RESULTS The calf inoculated with M bovis 12040577 did not develop corneal ulcers. Of the 22 eyes inoculated with M bovis Epp63-300, 18 developed corneal ulcers consistent with IBK within 48 hours after inoculation; 4 of those eyes developed secondary corneal ulcers that were not consistent with IBK. Corneal ulcer size and severity and the time required for ulcer healing did not differ between the treatment and control groups. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that B bacteriovorus 109J was not effective for the treatment of IBK; however, the experimental model used produced lesions that did not completely mimic naturally occurring IBK.

A granulomatous conjunctivitis associated with Morexella phenylpyruvica in an ostrich (Struthio camelus).

The aim of study was to evaluate a case of granulomatous conjunctivitis, clinically and pathologically, in the right eye of a 2-year-old, female ostrich. A mass measuring 5 cm x 3 cm x 4 cm was removed surgically from the eye of the ostrich. Morexella phenylpyruvica was recovered from the mass. On histopathological examination, hyperplasia or squamous metaplasia in some area of conjunctival palpebra, and a granulomatous inflammation in the submucosa were observed. The lesion was described as a granulomatous conjunctivitis caused by M. phenylpyruvica. The lesion was located in the lower eyelid conjunctiva and was not only restricted to the gl. lacrimalis, but also present in the connective tissue. After excision of the mass, the ostrich was treated with topical and systemic antibiotics and corticosteroid. The ostrich recovered fully and the function of the eye appeared to be normal.