Porcine hemothropic mycoplasmas infection associated with productive impact in intensive pig production

Abstract

Background So far, three porcine hemoplasmas (PH) have been identified, namely Mycoplasma suis, Mycoplasma parvum, and Mycoplasma haemosuis. The first one is the main agent associated with porcine hemoplasmosis, a possible cause of economic losses in pig production. Thus, this work aimed to detect and quantify PH 16S rRNA in finishing pigs and to associate its load estimate with average daily weight gain (ADWG). For this purpose, whole blood samples from 318 pigs were collected at an age of 75 days (d0) when the pigs entered the finishing phase and 105 days later (d105). To calculate ADWG, the animals were weighed at the abovementioned dates. Then, DNA from blood samples were submitted to a qPCR targeting the 16S rRNA gene for PH. Spearman correlation test was performed to investigate potential associations between ADWG and the quantification values. Lastly, the molecular characterization of PH was done by sequencing the 23S rDNA gene. Results Out of the 318 samples, 190 (59.74%) were positive on d0, and 304 (95.6%) were positive on d105. A significant correlation was observed (p < 0.05), albeit with a low coefficient value (0.18), when comparing ADWG with quantification values on d105. The phylogenetic analysis based on the 23S rDNA gene showed that four sequences were closely related to M. parvum, and one sequence was positioned in the M. suis cluster. Conclusion Two PH, M. suis and M. parvum, were detected in a Brazilian pig farm. Moreover, increasing occurrence through time was observed, which may have affected the productive performance of positive animals, mainly at the end of the finishing phase, when antimicrobials are removed.

Chemotherapeutic Strategies with Valnemulin, Tilmicosin, and Tulathromycin to Control Mycoplasma hyopneumoniae Infection in Pigs

“…In farms where antibiotics were withdrawn during the finishing phase, up to 95.60% of animals tested positive for Mycoplasma spp. [ 19 ].…”

Molecular detection and genetic analysis of porcine haemoplasmas in commercial pig farms from Thailand reveal a putative novel species

“…rRNA (Figure 3) and rnpB genes (Figure 4) revealed results that are similar to that of previous studies in which M. suis and M. parvum were clustered into the M. suis group and Ca. M. haemosuis was clustered into the M. haemofelis group (Fu et al, 2017;Petri et al, 2020;Seo et al, 2019;Watanabe et al, 2011) (Hoelzle, 2008;Tasker et al, 2018). Moreover, this method may lead to misinterpretation of haemoplasma infection from stain precipitation and Howell-Jolly bodies (Tasker et al, 2018).…”

“…M. haemosuis was clustered into the M . haemofelis group (Fu et al., 2017; Petri et al., 2020; Seo et al., 2019; Watanabe et al., 2011). Moreover, ntST networks provided results corresponding to phylogenetic trees.…”

“…M. haemosuis is in the M . haemofelis group based on phylogeny of RNase P RNA gene ( rnpB ) (Fu et al., 2017; Peters et al., 2008; Watanabe et al., 2011) and 23S rRNA gene sequences (Petri et al., 2020; Sonalio et al., 2021). In Thailand, only one porcine haemoplasma, M .…”

“…Similarly, M. suis and M. parvum are included in the M. suis group and Ca. M. haemosuis is in the M. haemofelis group based on phylogeny of RNase P RNA gene (rnpB) (Fu et al, 2017;Peters et al, 2008;Watanabe et al, 2011) and 23S rRNA gene sequences (Petri et al, 2020;Sonalio et al, 2021).…”