Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>

The typical clinical signs of <i>Nocardia seriolae</i> infection include white nodules, ranging from 0.1 to 10 mm in diameter, distributed across various internal organs. However, the structural composition of nodules of different sizes remains unexplored. In this study, natural cases of...

Full description

Saved in:
Bibliographic Details
Main Authors: Chengwei Li, Wenhui Wang, Fan Wu, Hao Pu, Lei Liao
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Fishes
Subjects:
Online Access:https://www.mdpi.com/2410-3888/9/12/515
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850042240660930560
author Chengwei Li
Wenhui Wang
Fan Wu
Hao Pu
Lei Liao
author_facet Chengwei Li
Wenhui Wang
Fan Wu
Hao Pu
Lei Liao
author_sort Chengwei Li
collection DOAJ
description The typical clinical signs of <i>Nocardia seriolae</i> infection include white nodules, ranging from 0.1 to 10 mm in diameter, distributed across various internal organs. However, the structural composition of nodules of different sizes remains unexplored. In this study, natural cases of largemouth bass (<i>Micropterus salmoides</i>) were collected, and pathogenic bacteria were isolated and confirmed through a re-infection experiment. The isolated bacteria were identified as <i>N. seriolae</i> through <i>16S rRNA</i> and <i>gyrB</i> gene sequencing. Healthy largemouth bass were infected with the isolate using an immersion infection and observed continuously over 56 days. Samples were successfully obtained from the incubation, prodromal, symptomatic, and convalescent phases, allowing for gross, histological, and ultrastructural observations of nodular lesion progression. Results demonstrated two types of nodular lesions: necrotic foci and granulomas. Macroscopically visible nodules larger than 1 mm, observed primarily in the liver, spleen, kidney, and muscle tissues of moribund fish, exhibited coagulative necrosis and were identified as the principal cause of mortality. Conversely, granulomas, with diameters less than 1 mm, were consistently present in the spleen, kidney, and liver during the symptomatic and convalescent phases.
format Article
id doaj-art-70d9abb4e7804edda92096784638e828
institution DOAJ
issn 2410-3888
language English
publishDate 2024-12-01
publisher MDPI AG
record_format Article
series Fishes
spelling doaj-art-70d9abb4e7804edda92096784638e8282025-08-20T02:55:37ZengMDPI AGFishes2410-38882024-12-0191251510.3390/fishes9120515Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>Chengwei Li0Wenhui Wang1Fan Wu2Hao Pu3Lei Liao4College of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, ChinaCollege of Veterinary Medicine, Gansu Agricultural University, Lanzhou 730070, ChinaCollege of Animal Husbandry and Veterinary, Chengdu Agricultural College, Chengdu 611130, ChinaCollege of Animal Husbandry and Veterinary, Chengdu Agricultural College, Chengdu 611130, ChinaCollege of Animal Husbandry and Veterinary, Chengdu Agricultural College, Chengdu 611130, ChinaThe typical clinical signs of <i>Nocardia seriolae</i> infection include white nodules, ranging from 0.1 to 10 mm in diameter, distributed across various internal organs. However, the structural composition of nodules of different sizes remains unexplored. In this study, natural cases of largemouth bass (<i>Micropterus salmoides</i>) were collected, and pathogenic bacteria were isolated and confirmed through a re-infection experiment. The isolated bacteria were identified as <i>N. seriolae</i> through <i>16S rRNA</i> and <i>gyrB</i> gene sequencing. Healthy largemouth bass were infected with the isolate using an immersion infection and observed continuously over 56 days. Samples were successfully obtained from the incubation, prodromal, symptomatic, and convalescent phases, allowing for gross, histological, and ultrastructural observations of nodular lesion progression. Results demonstrated two types of nodular lesions: necrotic foci and granulomas. Macroscopically visible nodules larger than 1 mm, observed primarily in the liver, spleen, kidney, and muscle tissues of moribund fish, exhibited coagulative necrosis and were identified as the principal cause of mortality. Conversely, granulomas, with diameters less than 1 mm, were consistently present in the spleen, kidney, and liver during the symptomatic and convalescent phases.https://www.mdpi.com/2410-3888/9/12/515<i>Nocardia seriolae</i><i>Micropterus salmoides</i>necrotic focigranulomas
spellingShingle Chengwei Li
Wenhui Wang
Fan Wu
Hao Pu
Lei Liao
Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>
Fishes
<i>Nocardia seriolae</i>
<i>Micropterus salmoides</i>
necrotic foci
granulomas
title Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>
title_full Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>
title_fullStr Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>
title_full_unstemmed Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>
title_short Pathological Progress of Two Types of Nodules in <i>Micropterus salmoides</i> Infected with <i>Nocardia seriolae</i>
title_sort pathological progress of two types of nodules in i micropterus salmoides i infected with i nocardia seriolae i
topic <i>Nocardia seriolae</i>
<i>Micropterus salmoides</i>
necrotic foci
granulomas
url https://www.mdpi.com/2410-3888/9/12/515
work_keys_str_mv AT chengweili pathologicalprogressoftwotypesofnodulesinimicropterussalmoidesiinfectedwithinocardiaseriolaei
AT wenhuiwang pathologicalprogressoftwotypesofnodulesinimicropterussalmoidesiinfectedwithinocardiaseriolaei
AT fanwu pathologicalprogressoftwotypesofnodulesinimicropterussalmoidesiinfectedwithinocardiaseriolaei
AT haopu pathologicalprogressoftwotypesofnodulesinimicropterussalmoidesiinfectedwithinocardiaseriolaei
AT leiliao pathologicalprogressoftwotypesofnodulesinimicropterussalmoidesiinfectedwithinocardiaseriolaei