Comparison of culture and PCR to detect Mycoplasma agalactiae and Mycoplasma mycoides subsp. capri in ear swabs taken from goats

Isolation and Characterization of Mycoplasma ovipneumoniae Infecting Goats with Pneumonia in Anhui Province, China

Mycoplasma ovipneumoniae (M. ovipneumoniae) causes a fatal infection in goats, leading to significant economic losses in the small-ruminant industry worldwide. The present study aimed to characterize the strains of M. ovipneumoniae infecting goats with pneumonia in Anhui Province, China. From November 2021 to January 2023, among 20 flocks, a total of 1320 samples (600 samples of unvaccinated blood, 400 nasal swabs, 200 samples of pleural fluid, and 120 samples of lung tissue) were obtained from goats with typical signs of pneumonia, such as a low growth rate, appetite suppression, increased temperature, discharge from the nose, and a cough. Necropsied goats showed increased pleural fluid, fibrinous pleuropneumonia, and attached localized pleural adhesions. M. ovipneumoniae isolated from the samples were subjected to an indirect hemagglutination test (IHA), PCR amplicon sequencing, phylogenetic analysis, and biochemical identification tests. The overall positivity rate of M. ovipneumoniae was 27.50%. Mycoplasmas were obtained from 80 (20.0%) nasal swabs, 21 (10.5%) pleural fluid samples, and 15 (12.5%) lung samples. PCR amplicon (288 bp) sequencing identified eight strains of M. ovipneumoniae. In a phylogenetic tree, the isolated strains were homologous to the standard strain M. ovipneumoniae Y-98 and most similar to M. ovipneumoniae FJ-SM. Local strains of M. ovipneumoniae were isolated from goats in Anhui province. The identified genomic features and population structure will promote further study of M. ovipneumoniae pathogenesis and could form the basis for vaccine and therapy development.

Mesomycoplasma ovipneumoniae from goats with respiratory infection: pathogenic characteristics, population structure, and genomic features

BACKGROUND

Mycoplasma ovipneumoniae is a critical pathogen that causes respiratory diseases that threaten Caprini health and cause economic damage. A genome-wide study of M. ovipneumoniae will help understand the pathogenic characteristics of this microorganism.

RESULTS

Toxicological pathology and whole-genome sequencing of nine M. ovipneumoniae strains isolated from goats were performed using an epidemiological survey. These strains exhibited anterior ventral lung consolidation, typical of bronchopneumonia in goats. Average nucleotide identity and phylogenetic analysis based on whole-genome sequences showed that all M. ovipneumoniae strains clustered into two clades, largely in accordance with their geographical origins. The pan-genome of the 23 M. ovipneumoniae strains contained 5,596 genes, including 385 core, 210 soft core, and 5,001 accessory genes. Among these genes, two protein-coding genes were annotated as cilium adhesion and eight as paralog surface adhesins when annotated to VFDB, and no antibiotic resistance-related genes were predicted. Additionally, 23 strains carried glucosidase-related genes (ycjT and group_1595) and glucosidase-related genes (atpD_2), indicating that M. ovipneumoniae possesses a wide range of glycoside hydrolase activities.

CONCLUSIONS

The population structure and genomic features identified in this study will facilitate further investigations into the pathogenesis of M. ovipneumoniae and lay the foundation for the development of preventive and therapeutic methods.

Clinical, histopathological, and molecular characterization of Mycoplasma species in sheep and goats in Egypt

Background and Aim:

Mycoplasma infection in small ruminants is a serious problem in sheep and goat herds around the world. It is responsible for high economic losses and decreased animal productivity. This study aimed to highlight the clinical, histopathological, minimum inhibitory concentration (MIC), and molecular characterization of Mycoplasma species in sheep and goats in Menoufiya Governorate, Egypt.

Materials and Methods:

A total of 234 samples were collected; 104 samples were collected from pneumonic lung tissues from the abattoir, in addition, 10 and 20 samples collected from apparently and diseased sheep, respectively, and 40 and 60 samples were collected from apparently and diseased goats, respectively, which were subjected to isolation onto pleuropneumonia-like organism medium. Polymerase chain reaction (PCR), histopathological examination, and determination of the MIC were also performed.

Results:

Of 104 samples of lung tissues showing pneumonic lesions, 56 (53.84%) were positive for Mycoplasma isolation. The positive isolation of Mycoplasma from 10 and 20 samples from apparently and diseased sheep was 30% and 40%, respectively as well as the positive isolation of Mycoplasma was 17% and 56.66% out of 40 and 60 apparently healthy and diseased field goat’s cases, respectively. All the diseased sheep and goats showed respiratory manifestations, including cough, bilateral nasal discharge, conjunctivitis, and systemic reaction. Evaluation of the MIC for Mycoplasmaovipneumoniae revealed that lincospectin and tylosin were the most effective antibiotics at 2.5 mg/mL. Histopathological examination of affected lung tissue showed extensive hemorrhagic pneumonia with extensive alveolar hemorrhage. The PCR technique proved to be a rapid, specific, and sensitive method for the detection of M. ovipneumoniae and Mycoplasma arginini at 390 and 326 bp, respectively.

Conclusion:

M. ovipneumoniae and M. arginini were the most prevalent species associated with respiratory infections in sheep and goats in the study area. Further studies are needed to investigate the role of these species in dissemination of the disease within herds of small ruminants.

Rapid detection of Mycoplasma mycoides subsp. capri and Mycoplasma capricolum subsp. capripneumoniae using high-resolution melting curve analysis

Mycoplasma capricolum subsp.subsp. capripneumonia (Mccp) and Mycoplasma mycoides subsp.sbusp. capri (Mmc) cause caprine pleuropneumonia (CCPP) and mycoplasmal pneumonia in goats and sheep (MPGS), respectively. These diseases cannot be identified on clinical symptoms alone and it is laborious to distinguish them using biochemical methods. It is therefore important to establish a simple, rapid identification method for Mccp and Mmc. Here, we report a high-resolution melting (HRM) curve analysis using specific primers based on the Mmc 95010 strain MLC_0560 and Mccp F38 strain MCCPF38_00984 gene sequences. The method was highly specific with intra- and inter-batch coefficients of variation < 1%. The lower limit of detection for Mccp and Mmc was 55 copies/μL and 58 copies/μL, respectively. HRM and fluorescence qPCR results were compared using 106 nasal swabs and 47 lung tissue samples from goats (HRM-qPCR coincidence rate 94.8%; 145/153). Mycoplasma isolation and identification was performed on 30 lung tissue samples and 16 nasal swabs (HRM-culturing coincidence rate 87.0%; 40/46). HRM analysis was more sensitive than fluorescence qPCR and Mycoplasma isolation, indicating the practicality of HRM for accurate and rapid identification of Mccp and Mmc, and diagnosis and epidemiology of CCPP and MPGS.

Molecular Identification of Mycoplasma agalactiae in Iran Based on P30 Gene

Mycoplasma agalactiae (M. agalactiae) is known as the main etiological agent of contagious agalactia (CA). The CA is a disease affecting dairy sheep and goats, the main characteristics of which include keratoconjunctivitis, arthritis, and mastitis. This pathogen results in milk production reduction and suppression, thereby leading to serious economic loss. In the present study, 125 sheep and goat samples were collected from 15 provinces of Iran. Cultural and molecular methods were used for sample characterization. After extracting genomic DNAs using the phenol/chloroform method, the PCR technique was employed to detect Mycoplasma genus in 163bp fragment of 16S rRNA gene (M-PCR) and M. agalactiae in 800bp fragment of conserve and specific P30 lipoprotein gene (P30-PCR) in cultural and clinical samples. Finally, to validate the experimental approach, a 375 bp amplicon of P80 lipoprotein was amplified using the MA-PCR. Out of 125 samples under investigation, 43 cases were positive, and Mycoplasma colonies were observed in the pleuropneumonia-like organisms agar culture. Based on the results of the M-PCR method, 61 specimens (out of 125 samples) were scored positive for Mycoplasma presence. Furthermore, 20 samples were positive according to the P30-PCR data. It should be mentioned that the MA-PCR was performed based on the P80 gene on 125 total samples to furtherverify the results for M.agalactiae detection. Based on the obtained data, P30 and P80 genes were presented and amplified in all Iranian M. agalactiae isolates (n=20). Our results indicated that the P30 gene was conserved and specific to all Iranian M. agalactiae isolates and this new P30-PCR method (as an MA-PCR technique) might be useful in the detection of this pathogen.

An outbreak of Mycoplasma mycoides subspecies capri arthritis in young goats: a case study

Mycoplasmosis is a well-known cause of morbidity and mortality in small ruminants. Previously recognized outbreaks have involved arthritis, and pneumonia or pleuropneumonia. Modern bacteriology procedures rely less on isolation techniques that require special media for mollicutes given that these species are notoriously difficult to isolate, and rely more on PCR tests. We report an outbreak of arthritis, pleuropneumonia, and mild meningitis affecting dairy goat kids, spanning a period of 3 y, which had unusual epidemiologic characteristics related to husbandry practices. Lesions were characterized by polyarthritis of the appendicular joints, with copious joint fluid and extension of arthritic exudate beyond the joint itself. The cause remained unknown until serendipitous isolation of a mycoplasma on blood agar. Mycoplasmosis was not detected from synovial samples by a general mycoplasma PCR, despite multiple attempts. Isolated colonies were also negative by this general PCR assay. The isolate was identified as Mycoplasma mycoides subspecies capri, using universal 16S primers and amplicon sequencing. Testing of additional isolates from other diseased goats in the herd confirmed that this was the cause of illness. A failure to recognize the distinct nature of organisms of the M. mycoides group of mycoplasmas meant that a PCR test that cannot detect this group of organisms was utilized at first, and the etiology of the illness was overlooked for a period of time. Veterinary pathologists and microbiologists must be aware of the limitations of some PCR assays when confronted with joint disease and pleuropneumonia in small ruminants.

Mycoplasma conjunctivae in insect vectors and anatomic locations related to transmission and persistence

Mycoplasma conjunctivae is an obligate microparasite that causes Infectious Keratoconjunctivitis (IKC) in Caprinae species. IKC is a long-recognised disease, but little attention has been paid to the mechanisms of transmission of the mycoplasma and its occurrence in locations other than the eyes. In this study, the presence of M. conjunctivae is assessed in the eyes, external ear canals (EEC), nasal cavity, and vagina of host species as well as in potential vectors, which may be involved in the transmission and persistence of infection within the host. M. conjunctivae was detected by qPCR in 7.2 % (CI 95% 4.7-11.0) of the ear swabs and 9.5 % (CI 95% 6.4-13.9) of the nasal swabs from Pyrenean chamois, Iberian ibex, domestic sheep and mouflon without statistical differences between species. Mycoplasma detection in nasal swabs was mostly associated with ocular infection (95.6%), but this was not the case for EEC (52.6%). Among the eye-positive ruminants, 27.3% were positive in ear swabs and 64.7% in nasal swabs, and the threshold cycle values of the qPCR were correlated only between eye and nasal swabs (p < 0.01; r₂ = 0.56). M. conjunctivae was detected in 1.7% - 7.1 % of Musca spp. captured during an IKC outbreak in Iberian ibex and in one out of three endemic sheep flocks. The results indicate that the transmission of M. conjunctivae may occur by direct contact with eye or nasal secretions and/or indirectly through flies. The M. conjunctivae DNA detection in EEC suggests that it can colonise the auditory tract, but the significance for its persistence within the host should be further assessed.

Rapid serum agglutination, cultural isolation and PCR for detection of M. gallisepticum and M. synoviae infection in poultry

Poultry mycoplasmosis, is an infectious disease of birds distributed worldwide causing serious economic loss to the poultry industry. Diagnosis of poultry mycoplasmosis is considered to difficult task due to different aspects of etiological agent from conventional bacteria. Therefore, the present study was aimed to detect mycoplasma infection in poultry using serological, cultural and molecular techniques. The specimens included were, sera samples and choanal swabs (150 each) collected from 150 birds housed in semi arid and costal area of Maharashtra (India). Mycoplasma gallisepticum (MG) was more prevalent than Mycoplasma synoviae (MS) in mycoplasmosis detected by rapid serum agglutination test (RSA), cultural isolation and direct PCR of samples. Nucleotide sequences of three representative MG isolates with NCBI accession nos. KY467400, KY467401 and KY467403 did not show any variations in their sequences analysed and matched with published strains of MG. RSA, cultural isolation and direct PCR yielded 93 (62%), 24 (16%) and 85 (56.67%) positive cases respectively. The sensitivity of PCR and RSA was 95.83% and 83.33% respectively. Thus, RSA and PCR were better than cultural isolation in diagnosis of poultry mycoplasmosis, therefore these methods can be used for screening the flocks for detection of mycoplasma infection depending on availability of specimens and facility.

Survey of Victorian small ruminant herds for mycoplasmas associated with contagious agalactia and molecular characterisation of Mycoplasma mycoides subspecies capri isolates from one herd

OBJECTIVE

Regarded as one of the most expensive production diseases of dairy sheep and goats, contagious agalactia (CA) is caused by any of four agents: Mycoplasma agalactiae, M. mycoides subspecies capri (Mmc), M. capricolum subspecies capricolum (Mcc) and M. putrefaciens. Although CA is worldwide in distribution, it has not been reported in Australia, even though studies between the 1950s and 1980s isolated each agent from sheep or goats without any clinical signs associated with it. The aim of this study was to examine sheep and goats in Victoria, Australia, for the presence of CA-associated mycoplasmas and to investigate the evolutionary relationships of these isolates by comparing their genetic differences with their counterparts from other parts of the world.

METHODS

A 3-year epidemiological survey of small ruminant populations in Victoria, Australia, was conducted for the presence of CA-associated mycoplasmas and the isolates obtained were genotyped by multilocus sequence typing (MLST).

RESULTS

Mmc was the only CA-associated agent isolated from the 1358 samples analysed in the study, but was not associated with CA on the property where it was found. MLST analyses of Mmc strains revealed a distinct clustering of Australian isolates into a novel clade, with the closest relatives being strains from Europe. The distinct clustering is consistent with the absence of clinical disease in Australia.

CONCLUSION

The isolation of Mmc indicates that this subspecies persists in Australian small ruminant populations. However, full genome sequencing and in vitro animal experimentation are needed to unequivocally demonstrate the avirulence of Australian strains.

Treatment and detection of mycoplasma contamination during cell culture

AIM: To eliminate and detect the contamination of mycoplasma during cell culture effectively.

METHODS: Three drugs (plasmocin, BM-Cyclin, and MRA) were used to treat the contaminated cells. CLRAK One Step Test Kit, Biotool Detection Kit and polymerase chain reaction (PCR) were used to detect the degree of contamination.

RESULTS: Plasmocin, BM-Cyclin, and MRA could eliminate the contamination effectively. Assay with the CLARK Kit showed that mycoplasma disappeared completely on 14^th day after treatment with plasmocin, the Biotool Detection Kit showed that the contamination disappeared completely on the 21^st day after treatment with BM-Cyclin, and PCR showed that mycoplasma disappeared completely on the 14^th day after treatment with MRA. The combination of the three drugs was more effective in the eradication of mycoplasma contamination.

CONCLUSION: The combination of three antibiotics and three mycoplasma detection methods can effectively control mycoplasma contamination during cell culture.

Contagious agalactia due to Mycoplasma spp. in small dairy ruminants: epidemiology and prospects for diagnosis and control

Contagious agalactia (CA) is a serious disease of small dairy ruminants that has a substantial economic impact on the goat and sheep milk industries. The main aetiological agent of the disease is Mycoplasma agalactiae, although other species, such as Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens, are pathogenic in goats. There are two clinical-epidemiological states of CA in sheep and goats; herds and flocks may exhibit outbreaks of CA or may be chronically infected, the latter with a high incidence of subclinical mastitis and only occasional clinical cases. The complex epidemiology of CA is related to the genetic characteristics and mechanisms of molecular variation of the Mycoplasma spp. involved, along with presence of CA-mycoplasmas in wild ruminant species. In goats, the situation is particularly complex and asymptomatic carriers have been detected in chronically infected herds. The coexistence of other non-pathogenic mycoplasmas in the herd further complicates the diagnosis of CA and the design of efficient strategies to control the disease. Routes of infection, such as the venereal route, may be involved in the establishment of chronic infection in herds. Current challenges include the need for improved diagnostic methods for detection of chronic and subclinical infections and for the design of more efficient vaccines.

One test microbial diagnostic microarray for identification of Mycoplasma mycoides subsp. mycoides and other Mycoplasma species

The present study describes the use of microarray technology for rapid identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. A microarray containing genetic sequences of 55 different bacterial species from Acholeplasma, Mycoplasma, Spiroplasma and Ureaplasma genera was constructed. Sequences to genes of interest were collected in FASTA format from NCBI. The collected sequences were processed with OligoPicker software. Oligonucleotides were then checked for their selectivity with BLAST searches in GenBank. The microarray was tested with ATCC/NCTC strains of Mycoplasma spp. of veterinary importance in ruminants including Mycoplasma belonging to the mycoides cluster as well as Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri field strains. The results showed that but one ATCC/NCTC reference strains hybridized with their species-specific sequences showed a profile/signature different and distinct from each other. The heat-map of the hybridization results for the nine genes interrogated for Mycoplasma mycoides subsp. mycoides demonstrated that the reference strain Mycoplasma mycoides subsp mycoides PG1 was positive for all of the gene sequences spotted on the microarray. CBPP field, vaccine and reference strains were all typed to be M. mycoides subsp. mycoides, and seven of the nine strains gave positive hybridization results for all of the nine genes. Two Italian strains were negative for some of the genes. Comparison with non-Mycoplasma mycoides subsp. mycoides reference strains showed some positive signals or considerable homology to Mycoplasma mycoides subsp. mycoides genes. As expected, some correlations were observed between the strictly genetically and antigenically correlated Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri strains. Specifically, we observed that some Italian Mycoplasma mycoides subsp. mycoides strains were positive for two out of the three Mycoplasma mycoides subsp. capri genes, differently from what has been observed for other European or African Mycoplasma mycoides subsp. mycoides strains. This study highlighted the use of microarray technology as a simple and effective method for a single-step identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. The opportunity to discriminate several mycoplasmas in a single analysis enhances diagnostic rapidity and may represent a useful tool to screen occasionally mycoplasmas affecting animal farming in territories where diagnostic laboratory support is limited. The heat-map of the hybridization results of the comparative genomic hybridizations DNA-designed chip clearly indicates that the microarray performs well for the identification of the tested Mycoplasma mycoides subsp. mycoides reference and field strains, discriminating them from other mycoplasmas.

Presence of contagious agalactia causing mycoplasmas in Spanish goat artificial insemination centres

Male goats admitted to artificial insemination centres come from herds that have shown no clinical symptoms of contagious agalactia (CA) for the last 6 mo. However, prior reports suggest that this control measure may not be completely effective. This study was designed to detect the presence of CA-causing mycoplasmas in 9 Spanish centres, comprising 159 goats (147 males and 12 teaser does) of 8 different breeds. A microbiological study was conducted during 8 mo on 448 samples (318 ear swabs, 119 semen samples and 11 milk samples). In 86 samples (84 swabs, 1 semen sample and 1 milk sample), CA-causative mycoplasmas were detected by PCR or culture, and 52 animals (49 goat males and 3 teaser does) tested positive. Most of these positive animals were auricular carriers (n = 50), mainly of Mycoplasma mycoides subsp. capri (Mmc), although some M. agalactiae (Ma) and, interestingly, M. capricolum subsp. capricolum (Mcc) carriers were also identified. At least 1 animal infected by CA-causing mycoplasmas was detected in 8 of the 9 centres (88.8%) although in most (66.7%) no infected animals or only 1 or 2 positive animals were identified. Our results indicate the presence of CA carriers as asymptomatic animals in reproductive programmes. These findings have already prompted efficient measures to detect and avoid the entry of these carriers in Spanish centres. We recommend similar measures for all centres in areas where CA is endemic.