The unusual isolation of carnobacteria in eyes of healthy salmonids in high‑mountain lakes

Carnobacteria are common bacteria in cold and temperate environments; they are also reported during fsh mortality events. In a previous study, carnobacteria were isolated from the eyes of healthy wild salmonids from a high-mountain lake. To better understand these fndings, salmonids were captured from three high-mountain lakes (Lower and Upper Balma Lake, Rouen Lake; northwest Italy) during August 2019 and subjected to bacteriological and histological examination. Although all were healthy, 8.7% (Lower Balma Lake), 24% (Upper Balma Lake), and 32.6% (Rouen Lake) were positive for carnobacteria colonization of the eyes. A Trojan-horse efect was hypothesized to explain carnobacteria isolation in the eye. This immune-escaping macrophage-mediated mechanism has been identifed in other Gram-positive bacteria. Biochemical, molecular, and phylogenetic analysis were carried out on isolated bacteria (Carnobacterium maltaromaticum and C. divergens). Based on previous references for carnobacteria isolated from fsh, C. maltaromaticum strains were tested for the pisA precursor gene of the bacteriocin piscicolin 126. Carnobacterium maltaromaticum strains were found to display genotypic heterogeneity and a low percentage of pisA positive amplifcation. Features of geomorphology, geographic isolation, and microbiota common to the three lakes are thought to be possibly related to our fndings. Moreover, terrestrial insects collected from the lake shoreline and the stomach contents were screened for the presence of carnobacteria. The salmonids in these high-mountain environments feed mainly on terrestrial insects, which are considered possible vectors for carnobacteria that might catabolize the exoskeleton chitin. All insects tested negative for carnobacteria, but as a small number of samples were analyzed, their role as possible vectors of infection cannot be excluded. Further studies are needed to corroborate our research hypothesis

Morganella morganii septicemia and concurrent renal crassicaudiasis in a Cuvier’s beaked whale (Ziphius cavirostris) stranded in Italy

Information regarding bacterial diseases in Cuvier's beaked whale (CBW, Ziphius cavirostris) is scattered and mostly incomplete. This report describes a case of septicemia by Morganella morganii in a juvenile male CBW with concurrent renal crassicaudiasis. The animal stranded along the Ligurian coastline (Italy) and underwent a systematic post-mortem examination to determine the cause of death. Histopathology showed lesions consistent with a septicemic infection, severe meningoencephalitis, and renal crassicaudiasis. An M. morganii alpha-hemolytic strain was isolated in pure culture from liver, lung, prescapular lymph node, spleen, hepatic and renal abscesses, and central nervous system (CNS). The antimicrobial susceptibility profile of the strain was evaluated with the minimum inhibitory concentrations (MICs) method and reduced susceptibility to Trimethoprim-Sulfamethoxazole is reported. Crassicauda sp. nematodes were retrieved from both kidneys. No other pathogens were detected by immunohistochemistry, serology, or biomolecular analyses. Toxicological investigations detected high concentrations of immunosuppressant pollutants in the blubber. The chronic parasitic infestation and the toxic effects of xenobiotics likely compromised the animal's health, predisposing it to an opportunistic bacterial infection. To our knowledge, this is the first description of M. morganii septicemia with CNS involvement in a wild cetacean

Mycobacterium fortuitum infection in silver arowana (Osteoglossum bicirrhosum)

A case of mycobacterial infection in silver arowana (Osteoglossum bicirrhosum) is described in the present work. An adult male silver arowana exhibited granulomas in the liver and spleen with acid-fast bacilli identified as Mycobacteria fortuitum. To our knowledge this is the first report of mycobacterial infection in this fish species

The fibrolamellar variant of hepatocellular carcinoma. Its association with focal nodular hyperplasia.

A case of fibrolamellar hepatocellular carcinoma (FL-HCC) associated with adjacent focal nodular hyperplasia (FNH) is described. These two regions were adjacent but distinct, both on gross and microscopic examination. Currently, it is unclear whether FL-HCC rarely arises in preexisting FNH, or whether FNH is a typical response to this vascular variant of hepatocellular carcinoma (HCC). The FNH region, which is peripheral, may be biopsied to exclude the underlying carcinoma, and thus lead to inadequate therapy. Previous reports of this association are reviewed