Transbound Emerg Dis. 2020;00:1–13. wileyonlinelibrary.com/journal/tbed | 1 © 2020 Wiley-VCH GmbH
Received: 26 March 2020
|
Revised: 27 July 2020
|
Accepted: 28 July 2020
DOI: 10.1111/tbed.13767
ORIGINAL ARTICLE
Genetic diversity of emerging hemotropic mycoplasmas in
domestic pigs from Brazil
Karina Sonalio
1
| Lívia Perles
1
| Igor Renan H. Gatto
2
| Renan B. do Amaral
1
|
Henrique M. S. Almeida
1
| José Vanderlei B. Galdeano
3
| Rafael F. C. Vieira
4,5
|
Marcos R. André
1
| Luis Guilherme de Oliveira
1
1
School of Agricultural and Veterinarian
Sciences, São Paulo State University
(Unesp), Jaboticabal, Brazil
2
Ourofino Animal Health, Cravinhos, Brazil
3
COMIGO Cooperative, Rio Verde, Brazil
4
Vector-Borne Diseases Laboratory,
Departament of Veterinary Medicine,
Universidade Federal do Paraná (UFPR),
Curitiba, Brazil
5
Global One Health initiative (GOHi), The
Ohio State University, Columbus, OH, USA
Correspondence
Luis Guilherme de Oliveira, School of
Agricultural and Veterinarian Sciences, São
Paulo State University (Unesp), Jaboticabal,
São Paulo, Brazil.
Email: luis.guilherme@unesp.br
Funding information
Coordenação de Aperfeiçoamento de
Pessoal de Nível Superior, Grant/Award
Number: 001
Abstract
Mycoplasma suis and Mycoplasma parvum bind strongly to erythrocytes and may
cause clinical hemoplasmosis in swine, affecting several age groups. Mycoplasma spp.
infected animals may be asymptomatic carriers and/or show nonspecific clinical signs.
In Brazil, information on genetic diversity associated with porcine hemoplasmas (PH)
has not been described yet. Therefore, this study has aimed to detect, quantify and
characterize the genetic diversity of PH in finishing pigs from technified farms in the
state of Goiás, central-western Brazil. Ethylenediaminetetraacetic acid-blood sam-
ples from 450 swine belonging to 30 different farms from Goiás state were collected
at the slaughterhouse. Quantitative real-time PCR (qPCR) assays were performed for
the molecular detection and quantification of PH 16S rRNA gene fragments. Cloning
and sequencing of 16S and 23S rRNA amplicons were performed to evaluate the
genetic diversity. Moreover, a questionnaire was applied to each farm manager to
obtain epidemiological information about the herd. The results on qPCR showed herd
occurrence of 68.89% for PH. Quantification values (starting quantity [SQ]) ranged
from 8.43 × 10
−1
to 4.69 × 10
6
copies/µl, and 52.71% of the samples presented SQ
values equal or lower than 1 × 10
3
copies/µl. Risk factors were not evaluated once all
farms had at least one positive animal. However, Spearman's coefficient test revealed
that the occurrence of PH was inversely associated with the number of farrows per
week, weaned piglets per week, and weight at slaughter. Phylogenetic analysis based
on maximum likelihood and Bayesian methods showed that the 16S rRNA and 23S
rRNA gene sequences obtained from five samples formed a single cluster closely re-
lated to M. parvum. Genotype analysis using DNASP software confirmed seven and
four different 16S and 23S rRNA genotypes among the cloned amplicons, indicat-
ing that there are several genotypes of M. parvum circulating in individual pigs and
among pig farms in central-western Brazil.
KEYWORDS
emerging disease, genotypes, intensive pig farming, Mycoplasma parvum, Mycoplasma suis,
porcine hemoplasmas