METHODS: Relevant published studies, literature and reports were searched from accessible electronic databases and related institutional databases. We used keywords, viz; microbiome, microbiota, microbiome drug delivery and respiratory disease. Selected articles were carefully read through, clustered, segregated into subtopics and reviewed.
FINDINGS: The traditional belief of sterile lungs was challenged by the emergence of culture-independent molecular techniques and the recently introduced invasive broncho-alveolar lavage (BAL) sampling method. The constitution of a lung microbiome mainly depends on three main ecological factors, which include; firstly, the immigration of microbes into airways, secondly, the removal of microbes from airways and lastly, the regional growth conditions. In healthy conditions, the microbial communities that co-exist in our lungs can build significant pulmonary immunity and could act as a barrier against diseases, whereas, in an adverse way, microbiomes may interact with other pathogenic bacteriomes and viromes, acting as a cofactor in inflammation and host immune responses, which may lead to the progression of a disease. Thus, the use of microbiota as a target, and as a drug delivery system in the possible modification of a disease state, has started to gain massive attention in recent years. Microbiota, owing to its unique characteristics, could serve as a potential drug delivery system, that could be bioengineered to suit the interest. The engineered microbiome-derived therapeutics can be delivered through BC, bacteriophage, bacteria-derived lipid vesicles and microbe-derived extracellular vesicles. This review highlights the relationships between microbiota and different types of respiratory diseases, the importance of microbiota towards human health and diseases, including the role of novel microbiome drug delivery systems in targeting various respiratory diseases.
METHODS: Forty cats aged between 2 months and 11 years old (median 6 months) that were definitively diagnosed with rhodococcosis between 2012 and 2018 were recruited in this study. Medical records were reviewed for information on signalment, history, clinical presentation, diagnostic testing, treatment plans and clinical outcomes.
RESULTS: Of the 40 cats, 36 showed the pulmonary form of the disease, with 35 (87.5%) presenting with dyspnoea, while four cats presented with only cutaneous lesions. Mean body temperature was 38.7 ± 0.2°C. Dyspnoea was noted in 87.5% of the cats. Leukocytosis (58.3%) with band neutrophilia (83.3%), monocytosis (58.3%) and thrombocytopenia (55.5%) were prominent findings in the haematology reports. Hyperproteinaemia (61.1%) with hypoalbuminaemia (22.2%) and hyperglobulinaemia (63.8%) with a low albumin:globulin ratio (38.9%) were prominent features of blood biochemistry reports. An alveolar-interstitial pattern was noted in 75% of pre-thoracocentesis radiographs. Pleural effusion, hepatomegaly, thoracic lymphadenopathy and atelectasis of any lung lobe were seen in 88.9%, 75%, 41.7% and 36.1% of cats, respectively. Overall, the mortality rate was 67.5% in both forms.
CONCLUSIONS AND RELEVANCE: Clinicians should be aware that feline rhodococcosis manifests as a pulmonary disease at a much higher rate than previously reported. Further studies are required to address the epidemiology, pathophysiology, disease management and prognosis of feline rhodococcosis. The role of immunosuppression as a predisposing factor in feline rhodococcosis requires further investigation.