The Bovine Lung in Biomedical Research: Visually Guided Bronchoscopy, Intrabronchial Inoculation and <em>In Vivo</em> Sampling Techniques

Abstract

There is an ongoing search for alternative animal models in research of respiratory medicine. Depending on the goal of the research, large animals as models of pulmonary disease often resemble the situation of the human lung much better than mice do. Working with large animals also offers the opportunity to sample the same animal repeatedly over a certain course of time, which allows long-term studies without sacrificing the animals.The aim was to establish in vivo sampling methods for the use in a bovine model of a respiratory Chlamydia psittaci infection. Sampling should be performed at various time points in each animal during the study, and the samples should be suitable to study the host response, as well as the pathogen under experimental conditions. Bronchoscopy is a valuable diagnostic tool in human and veterinary medicine. It is a safe and minimally invasive procedure. This article describes the intrabronchial inoculation of calves as well as sampling methods for the lower respiratory tract. Videoendoscopic, intrabronchial inoculation leads to very consistent clinical and pathological findings in all inoculated animals and is, therefore, well-suited for use in models of infectious lung disease. The sampling methods described are bronchoalveolar lavage, bronchial brushing and transbronchial lung biopsy. All of these are valuable diagnostic tools in human medicine and could be adapted for experimental purposes to calves aged 6-8 weeks. The samples obtained were suitable for both pathogen detection and characterization of the severity of lung inflammation in the host.

Coxiella burnetii Infects Primary Bovine Macrophages and Limits Their Host Cell Response

“…For the preparation of alveolar macrophages, bronchoalveolar lavage (BAL) fluid was extracted from the lungs of clinically healthy calves with a protocol described before (36). After a washing step, cells were harvested and cultured in IMDM culture medium 2.…”

Evaluation of antimicrobial treatment in a bovine model of acuteChlamydia psittaciinfection: tetracycline versus tetracycline plus rifampicin

“…Preparation of the challenge strain was described elsewhere (Reinhold et al, 2012). Bronchoscopical and intranasal inoculation was performed with 8 mL of the chlamydia-containing inoculum as described previously (Prohl et al, 2014). Groups were age matched, and weight (72.9 AE 6.7 kg, mean AE SD) of the animals did not differ statistically significantly between the groups at the time of inoculation (Kruskal-Wallis test, P > 0.98).…”

“…Endoscopic sampling of BALF in the anesthetized animal was performed as described previously (Prohl et al, 2014). The BALF recovery in vivo was 83.1 AE 4.6 % (mean AE SD) and did not differ significantly between the treatment groups.…”

“…On 4 and 9 d.p.i., bronchial brushings were obtained during bronchoscopy from the right lung, just caudal of the Bifurcatio tracheae as described previously (Prohl et al, 2014). The brush was then rinsed in stabilizing SPGA medium [containing sucrose, phosphatile substances, glucose, and bovine albumin (Bovarnick et al, 1950)].…”

Illumina MiSeq 16S amplicon sequence analysis of bovine respiratory disease associated bacteria in lung and mediastinal lymph node tissue

“…Contig assemblies were generated using OMEGA metagenome assembler (V1.0.2) with default settings. BLAST (BLASTN 2.3.0+) searches against the non-redundant nucleotide collection database on the NCBI website [43,44] were conducted to determine known bacterial sequences that were most similar to the contig assemblies.…”