Functional surface expression of immunoglobulin cleavage systems in a candidate Mycoplasma vaccine chassis.

The Mycoplasma Immunoglobulin Binding/Protease (MIB-MIP) system is a candidate 'virulence factor present in multiple pathogenic species of the Mollicutes, including the fast-growing species Mycoplasma feriruminatoris. The MIB-MIP system cleaves the heavy chain of host immunoglobulins, hence affecting antigen-antibody interactions and potentially facilitating immune evasion. In this work, using -omics technologies and 5'RACE, we show that the four copies of the M. feriruminatoris MIB-MIP system have different expression levels and are transcribed as operons controlled by four different promoters. Individual MIB-MIP gene pairs of M. feriruminatoris and other Mollicutes were introduced in an engineered M. feriruminatoris strain devoid of MIB-MIP genes and were tested for their functionality using newly developed oriC-based plasmids. The two proteins are functionally expressed at the surface of M. feriruminatoris, which confirms the possibility to display large membrane-associated proteins in this bacterium. However, functional expression of heterologous MIB-MIP systems introduced in this engineered strain from phylogenetically distant porcine Mollicutes like Mesomycoplasma hyorhinis or Mesomycoplasma hyopneumoniae could not be achieved. Finally, since M. feriruminatoris is a candidate for biomedical applications such as drug delivery, we confirmed its safety in vivo in domestic goats, which are the closest livestock relatives to its native host the Alpine ibex.

Molecular detection, risk factors, and phylogenetic analysis of tick-borne pathogens in dogs from northern Vietnam.

In tropical regions, numerous tick-borne pathogens (TBPs) play a crucial role as causative agents of infectious diseases in humans and animals. Recently, the population of companion and pet dogs has significantly increased in Vietnam; however, information on the occurrence of TBPs is still limited. The objectives of this investigation were to determine the occurrence rate, risk factors, and phylogenetic characteristics of TBPs in dogs from northern Vietnam. Of 341 blood samples tested by PCR, the total infection of TBPs was 73.9% (252/341). Babesia vogeli (18SrRNA gene - 30.5%) was detected most frequently in studied dogs followed by Rickettsia spp. (OmpA gene - 27%), Anaplasma platys (groEL gene - 22%), Bartonella spp. (16SrRNA - 18.8%), Mycoplasma haemocanis (16SrRNA - 9.4%) and Hepatozoon canis (18SrRNA gene - 1.2%), respectively. All samples were negative for Ehrlichia canis and Anaplasma phagocytophylum. Co-infection was detected in 31.4% of the samples (107/341) of which, A. platys/Bartonella spp. (34/94,10%), Rickettsia spp./B. vogeli (19/94, 5.6%), and M. haemocanis/B. vogeli (19/94, 5.6%) were recorded as the three most frequent two species of co-infection types. Statistical analysis revealed a significant correlation between TBP infection and several host variables regarding age, breed, and living area in the current study. The recent findings reported herein, for the first time in Vietnam, are essential for local veterinarians when considering the appropriate approaches for diagnosing these diseases. Furthermore, this data can be used to establish control measures for future surveillance and prevention strategies against canine TBPs in Vietnam.

Evaluation of endothelial glycocalyx injury biomarkers in feline hemotropic mycoplasmosis.

The present study aimed to investigate endothelial glycocalyx (eGCx) damage in cats with feline hemotropic mycoplasmosis caused by Mycoplasma haemofelis using selected biomarkers and to determine the diagnostic and prognostic significance of these biomarkers. The study included 25 cats with feline hemotropic mycoplasmosis and 10 healthy cats. Clinical examination, blood gas analysis, complete blood count, and biochemical analysis were performed. Hemotropic mycoplasmosis diagnosed by microscopic examination and molecularly confirmed by PCR targeting the Mycoplasma haemofelis 16s rRNA gene. To evaluate endothelial glycocalyx damage, syndecan-1, endothelin-1 (ET-1), asymmetric dimethylarginine (ADMA), and vascular endothelial growth factor-A (VEGF-A) concentrations were measured using cat-specific commercial ELISA kits. Of the cats with feline hemotropic mycoplasmosis, 14 (56%) survived and 11 (44%) died. While syndecan-1 and ET-1 concentrations were significantly higher in cats with hemotropic mycoplasmosis compared to the control group (p < 0.001), no statistically significant difference was found for ADMA and VEGF-A concentrations (p > 0.05). Endothelial glycocalyx biomarkers showed significant correlations with each other and with hematological parameters (p < 0.01). The results of the ROC analysis showed that ET-1 with area under the curve (AUC) of 0.821 (p < 0.01) and VEGF-A with AUC of 0.805 (p < 0.010) were found to be significant prognostic indicators. In conclusion, this study demonstrated that serum syndecan-1 and ET-1 can be used as diagnostic and serum ET-1 and VEGF-A as prognostic biomarkers in cats with hemotropic mycoplasmosis. Our results indicate the development of eGCx damage in feline hemotropic mycoplasmosis and suggest that glycocalyx disruption may contribute to the pathogenesis of the disease.

Molecular prevalence and phylogenetic analysis of hemotropic Mycoplasma species in cats in different regions of Iran.

BACKGROUND: Hemotropic Mycoplasma species (hemoplasmas) cause hemolytic anemia in cats worldwide and are recognized as emerging zoonotic pathogens. There is no comprehensive study on the prevalence and species diversity of hemoplasmas in domestic cat populations in different regions in Iran. Thus, the aims of the present study were to provide data on the prevalence and molecular characterization of hemotropic Mycoplasma species in apparently healthy cats from six Iranian provinces with different climates. In addition, potential risk factors associated with hemoplasmosis in cats were assessed. RESULTS: Mycoplasma spp. DNA was detected in the blood of 56 / 361 cats (15.5%) using genus-specific PCR. Further examinations with species-specific PCR and Sanger sequencing showed that 38 cats (10.5%) tested positive for Candidatus Mycoplasma haemominutum (CMhm), 8 cats (2.2%) tested positive for Mycoplasma haemofelis (Mhf), and 2 cats (0.6%) tested positive for Candidatus Mycoplasma turicensis (CMt). Co-infection with CMhm, and Mhf was observed in 7 cats (1.9%). One cat (0.3%) showed mixed infection with CMhm, Mhf, and CMt. There were statistically significant relationships between Mycoplasma positivity and being female, living in shelter (cattery), and being over 3 years old (P < 0.05). No significant association was observed for the cat breed and sampling localities. CONCLUSIONS: Current study findings revealed that hemoplasma infections are common among Iran cat populations. Considering the impact of such emerging zoonotic pathogens on the One Health, routine screenings, increasing public awareness, effective control, and prophylactic strategies for minimizing infection in cats and subsequently in human are strongly recommended.

Analysis of the Spectrum of Common Pathogens and the Resistance of Mycoplasma in Sialidase-Positive Bacterial Vaginosis.

BACKGROUND: The objective of this study is to understand the characteristics of the common spectrum of pathogen and the resistance of Mycoplasma in Sialidase-positive bacterial vaginosis. METHODS: The vaginal secretion specimens collected from August 2018 to October 2018 for the analysis of bacterial vaginosis (BV) were subjected to various techniques. These included routine leukorrhea examination, bacterial vaginosis sialidase testing, routine culture for common pathogens, mass spectrometry identification, and Mycoplasma resistance testing. RESULTS: A total of 238 patients with BV were identified. The cleanliness grading was mostly clean (+) and clean (2+), accounting for 38.24% and 30.67%, respectively. The bacterial vaginosis test for vaginal secretions showed leukocyte esterase positivity in 220 cases, resulting in a positivity rate of 92.44%. The spectrum of routine culture was analyzed and divided into four groups: A, B, C, and D. Group A consisted of Candidal vaginitis (13.45%); group B consisted of Gardnerella vaginalis vaginitis (32.77%); group C consisted of gram-negative bacillus vaginitis (46.22%); and group D consisted of Streptococcus agalactiae vaginitis (7.56%). The identification and antimicrobial susceptibility testing results for Mycoplasma showed a high detection rate of BV, with a positivity rate of 86.13%. There was a high sensitivity to tetracyclines for Ureaplasma urealyticum and Mycoplasma hominis, but a high resistance to macrolides and quinolones. CONCLUSIONS: Bacterial vaginosis existed in various complex forms, including Candida, Gardnerella vaginalis, Gram-negative bacillus, and Streptococcus agalactiae types. Moreover, there was an increasing trend of multi-drug resistance in Mycoplasma hominis. Therefore, it is crucial to pay attention to this condition and make accurate judgments based on the etiological characteristics and common antimicrobial susceptibility tests. This will enable the implementation of effective therapeutic interventions.

Interactions between Mycoplasma mycoides subsp. mycoides and bovine macrophages under physiological conditions.

We investigated the interactions of unopsonized and opsonized Mycoplasma mycoides subsp. mycoides (Mmm) with bovine macrophages in vitro. Mmm survived and proliferated extracellularly on bovine macrophage cell layers in the absence of Mmm-specific antisera. Bovine complement used at non-bactericidal concentrations did neither have opsonizing effect nor promoted intracellular survival, whereas Mmm-specific antisera substantially increased phagocytosis and Mmm killing. A phagocytosis-independent uptake of Mmm by macrophages occurred at a high multiplicity of infection, also found to induce the production of TNF, and both responses were unaffected by non-bactericidal doses of bovine complement. Bovine complement used at higher doses killed Mmm in cell-free cultures and completely abrogated TNF responses by macrophages. These results provide a framework to identify Mmm antigens involved in interactions with macrophages and targeted by potentially protective antibodies and point towards a pivotal role of complement in the control of inflammatory responses in contagious bovine pleuropneumonia.

Characterization of Actin-based Genotypes and Mycoplasma Endosymbionts of Trichomonas vaginalis Isolated in Sapporo, Japan.

PURPOSE: Trichomonas vaginalis is a causative agent of common non-viral sexually transmitted infections worldwide. However, the biological features, such as genotypes and endosymbionts, of T. vaginalis isolated in Japan remain unclear. The aim of this study was to characterize the actin-based genotypes and the endosymbionts of T. vaginalis isolated in Sapporo, Japan. METHODS: Three T. vaginalis clinical strains were isolated in Sapporo, Japan between 2019 and 2022. Actin-based genotyping was conducted by sequencing and phylogenetic analyses. The endosymbionts, such as Mycoplasma sp. and Trichomonasvirus, were detected using PCR and RT-PCR, respectively. Furthermore, the detected Mycoplasma spp. were identified using 16S rRNA gene sequencing. RESULTS: Of the three T. vaginalis strains, two belonged to genotype E, whereas one was genotype G as determined by actin-based genotyping. Two of the T. vaginalis strains harbored Mycoplasma spp. Using nearly full-length 16S rRNA gene sequencing, both were identified as Candidatus Mycoplasma girerdii. In contrast, the Trichomonasvirus was not found in the T. vaginalis strains. CONCLUSION: To our knowledge, this is the first report on the characterization of actin-based genotypes and the presence of endosymbiotic Ca. M. girerdii in T. vaginalis strains in Japan. Thus, this study will provide an important impetus for future research.

Post-mortem detection of hemoplasmas (hemotropic Mycoplasma spp.) in South American fur seal (Arctocephalus australis) sampled in Rio Grande do Sul State, southern Brazil.

Hemotropic mycoplasmas are bacteria that attaches to erythrocytes surface, which some species presents zoonotic concerns. In the suborder Pinnipedia, genera Otaria and Arctocephalus are prominent in Brazil. This study investigated the occurrence of hemoplasmas in Arctocephalus sp. and Otaria flavescens found dead along the coast of a Southern Brazilian State. DNA from 135 spleen samples were extracted and subjected to conventional PCR protocols, targeting the 16 S rRNA and 23 S rRNA gene. Three (2.22 %) Arctocephalus australis were positive in the 16 S rRNA gene, and no samples amplified in the 23 S rRNA gene. Samples from this study clustered with Zalophus californianus and Arctocephalus tropicalis mycoplasmas on a Bayesian phylogenetic analysis. Genetic diversity analysis suggested distinct genotypes, indicating A. australis as a new host for hemoplasma, and also a potential putative novel hemoplasma genotype. These findings raises future awareness for pinnipeds conservation, and adds Mycoplasma spp. to be taken into consideration when clinically evaluating rescued animals.

The complete genome sequence of unculturable Mycoplasma faucium obtained through clinical metagenomic next-generation sequencing.

Introduction: Diagnosing Mycoplasma faucium poses challenges, and it's unclear if its rare isolation is due to infrequent occurrence or its fastidious nutritional requirements. Methods: This study analyzes the complete genome sequence of M. faucium, obtained directly from the pus of a sternum infection in a lung transplant patient using metagenomic sequencing. Results: Genome analysis revealed limited therapeutic options for the M. faucium infection, primarily susceptibility to tetracyclines. Three classes of mobile genetic elements were identified: two new insertion sequences, a new prophage (phiUMCG-1), and a species-specific variant of a mycoplasma integrative and conjugative element (MICE). Additionally, a Type I Restriction-Modification system was identified, featuring 5'-terminally truncated hsdS pseudogenes with overlapping repeats, indicating the potential for forming alternative hsdS variants through recombination. Conclusion: This study represents the first-ever acquisition of a complete circularized bacterial genome directly from a patient sample obtained from invasive infection of a primary sterile site using culture-independent, PCR-free clinical metagenomics.

A case of mistaken identity: a systematic review, meta-analysis, and reinvestigation of hemotropic Mycoplasma spp. infection in Ctenocephalides felis (cat flea).

BACKGROUND: Feline-associated hemotropic Mycoplasma (hemoplasmas) are believed to be transmitted by two primary mechanisms: (1) direct transmission via fighting and (2) vector-borne transmission by the cat flea (Ctenocephalides felis). While the efficiency of transmission by C. felis appears low, most manuscripts focus on the prevalence of hemoplasmas in wild-caught fleas and report either a very low (< 3%) or a high (> 26%) prevalence. Therefore, we aimed to assess the influence of sample processing and PCR methods on C. felis hemoplasma infection prevalence. METHODS: A systemic review of PubMed articles identified 13 manuscripts (1,531 fleas/flea pools) that met the inclusion criteria (performed PCR for >1 hemoplasma on C. felis collected from cats). Risk of bias was assessed utilizing the ROBINS-E tool. Meta-analysis performed in R of these manuscripts found that not washing samples and a common set of 16S rRNA primers first published in Jensen et al. 2001 were associated with increased hemoplasma prevalence. To evaluate the influence of washing on newly collected fleas, we assessed the hemoplasma status of 20 pools of 5 C. felis each, half of which were washed and half not washed. RESULTS: Flea washing did not influence the detection of hemoplasma but instead amplified Spiroplasma. To assess non-specific amplification with the Jensen et al. 2001 primers, 67 C. felis samples (34% previously reported hemoplasma infected) were subject to PCR and sequencing. By this method, hemoplasma was detected in only 3% of samples. In the remaining "hemoplasma infected" fleas, PCR amplified Spiroplasma or other bacteria. CONCLUSIONS: Therefore, we concluded that hemoplasma infection in C. felis is rare, and future flea prevalence studies should sequence all positive amplicons to validate PCR specificity. Further investigation of alternative methods of feline-associated hemoplasma transmission and the ability of C. felis to maintain hemoplasma infection is necessary.

Hemopathogens in naturally infected bovine fetuses in Brazil.

The transplacental transmission of parasites and hemoparasites is crucial for understanding the epidemiology of diseases. This study aimed to assess the prevalence of hemopathogens in bovine fetuses at various gestational periods. Samples were obtained from a slaughterhouse in the state of Minas Gerais, Brazil, and a total of 236 fetuses were collected. DNA extracted from blood samples (145) and organ samples (a pool of brain and spleen) (236) underwent a nested PCR (nPCR) assay to detect Babesia spp., Theileria spp., Trypanosoma vivax, Anaplasma marginale, Anaplasma bovis, Anaplasma phagocytophilum, Ehrlichia minasensis, and hemotropic Mycoplasma spp. Additionally, serological analysis of 145 plasma samples was conducted using the indirect fluorescent antibody test-IFAT to detect IgG against Babesia bovis, Babesia bigemina, A. marginale, and Trypanosoma vivax. The observed prevalence of transplacental transmission was 19.3 %, 6.2 %, 42.7 % and 2.7 %, for A. marginale, B. bigemina, 'Candidatus M. haemobos', and Mycoplasma wenyonii, respectively. The prevalence of A. marginale by gestational trimester was 16 % (13/81) in the second trimester and 23 % (14/60) in the third trimester, with no positive samples in the first trimester. Regarding the species B. bovis and B. bigemina, all evaluated animals tested negative by nPCR, and no serological evidence for B. bovis was found by the IFAT. Babesia bigemina demonstrated an overall seroprevalence of 6.2 % (9/145), with 4.8 % (7/145) in the last trimester and 1.3 % (2/145) in the second trimester of pregnancy. In total, 42.7 % (62/145) of blood samples were positive for 'Candidatus M. haemobos', with 42 % (34/81) in the middle trimester, and 43 % (26/60) in the final trimester of pregnancy. Mycoplasma wenyonni was detected in 2.7 % (4/145) blood samples, all in coinfection with 'C. M. haemobos'. The prevalence by pregnancy trimester was 25 % (1/4) in the first trimester; 1.2 % (1/81) in the second trimester and 3.3 % (2/60) in the third trimester of pregnancy. Hemopathogen DNA was detected in fetus blood samples but not the brain or spleen samples. All the samples were negative for T. vivax, Theileria spp., Anaplasma spp. and Ehrlichia spp. Overall, in this study, approximately 70 % of fetuses were positive for one or more of the studied parasites. No significant associations were observed between pairs of pathogens, except 'C. M. haemobos' and A. marginale.

Antimicrobial resistance (AMR): an important one health issue for layer and meat poultry industries worldwide.

Routine antibiotic administration has been used in intensive animal industries for a long time for health and production benefits. There is now a concerted effort to limit antibiotics administration to only treatment of clinically affected animals and to look for other alternative solutions combined with better husbandry practices for the benefits routine antibiotic administration seems to provide in intensive farming systems. In this paper it is argued that the benefits from routine antibiotics in chickens administration in lay are from suppression of the effects of mycoplasma infections. Mycoplasma freedom has been recommended but is not always practical. Vaccination of mycoplasma negative chickens with live mycoplasma vaccines is now being used (with biosecurity) to decrease antibiotic dependence in lay of poultry in many parts of the world.

Developing a platform for secretion of biomolecules in Mycoplasma feriruminatoris.

BACKGROUND: Having a simple and fast dividing organism capable of producing and exposing at its surface or secreting functional complex biomolecules with disulphide bridges is of great interest. The mycoplasma bacterial genus offers a set of relevant properties that make it an interesting chassis for such purposes, the main one being the absence of a cell wall. However, due to their slow growth, they have rarely been considered as a potential platform in this respect. This notion may be challenged with the recent discovery of Mycoplasma feriruminatoris, a species with a dividing time close to that of common microbial workhorses. So far, no tools for heterologous protein expression nor secretion have been described for it. RESULTS: The work presented here develops the fast-dividing M. feriruminatoris as a tool for secreting functional biomolecules of therapeutic interest that could be used for screening functional mutants as well as potentially for protein-protein interactions. Based on RNAseq, quantitative proteomics and promoter sequence comparison we have rationally designed optimal promoter sequences. Then, using in silico analysis, we have identified putative secretion signals that we validated using a luminescent reporter. The potential of the resulting secretion cassette has been shown with set of active clinically relevant proteins (interleukins and nanobodies). CONCLUSIONS: We have engineered Mycoplasma feriruminatoris for producing and secreting functional proteins of medical interest.

Minimal Bacterial Cell JCVI-syn3B as a Chassis to Investigate Interactions between Bacteria and Mammalian Cells.

Mycoplasmas are atypical bacteria with small genomes that necessitate colonization of their respective animal or plant hosts as obligate parasites, whether as pathogens, or commensals. Some can grow axenically in specialized complex media yet show only host-cell-dependent growth in cell culture, where they can survive chronically and often through interactions involving surface colonization or internalization. To develop a mycoplasma-based system to identify genes mediating such interactions, we exploited genetically tractable strains of the goat pathogen Mycoplasma mycoides (Mmc) with synthetic designer genomes representing the complete natural organism (minus virulence factors; JCVI-syn1.0) or its reduced counterpart (JCVI-syn3B) containing only those genes supporting axenic growth. By measuring growth of surviving organisms, physical association with cultured human cells (HEK-293T, HeLa), and induction of phagocytosis by human myeloid cells (dHL-60), we determined that JCVI-syn1.0 contained a set of eight genes (MMSYN1-0179 to MMSYN1-0186, dispensable for axenic growth) conferring survival, attachment, and phagocytosis phenotypes. JCVI-syn3B lacked these phenotypes, but insertion of these genes restored cell attachment and phagocytosis, although not survival. These results indicate that JCVI-syn3B may be a powerful living platform to analyze the role of specific gene sets, from any organism, on the interaction with diverse mammalian cells in culture.

The Role of Ureaplasma and Mycoplasma Species in Recurrent Lower Urinary Tract Infection in Females: A Scoping Review.

It is unknown if recurrent urinary tract infection in the gynecologic population is associated with Mycoplasma and Ureaplasma genitourinary infections. The purpose of this scoping review is to highlight the literature surrounding Mycoplasma and Ureaplasma infections in the setting of recurrent urinary tract infections in the gynecologic population. MEDLINE ALL and Embase were searched to retrieve articles published in or after 1950 through 2024. Studies included were those with adults over age 18, non-pregnant, diagnosed with recurrent urinary tract infection and concurrent genitourinary infection with Ureaplasma or Mycoplasma published in English. Study designs eligible were quantitative, qualitative, and mixed methods studies. Publication types were also extended to conference abstracts and unpublished data. 2 independent investigators systematically performed title/abstract screening and full-text review using standardized inclusion criteria. For disagreements in either title and abstracts or full-text articles, consensus was reached through discussion by the 2 screeners and/or a 3rd final adjudicator. Screening and data extraction were performed on Covidence, a web-based platform for systematic review management. There were 1170 studies identified before title and abstract screening. 26 full-text articles were reviewed for eligibility. Of these, 23 full-text studies were excluded. 3 studies met full inclusion criteria and data extraction was performed on these 3 studies. There were 2 additional studies included after identification via other methods. There is a need for more recent and robust studies examining the role of Ureaplasma and Mycoplasma genitourinary infections amongst gynecologic patients with recurrent urinary tract infections.

Seroprevalence of contagious bovine pleuropneumonia (CBPP) in cattle from Karamoja region, North-eastern Uganda.

BACKGROUND: Contagious bovine pleuropneumonia [CBPP] is a transboundary animal disease of cattle caused by Mycoplasma mycoides subsp. mycoides [Mmm]. CBPP causes severe economic losses to livestock producers in sub-Saharan Africa mainly due to high mortality, morbidity, reduction in productivity as well as livestock trade restrictions. This study aimed at determining seroprevalence of Mmm in cattle from Karamoja region, north-eastern Uganda; data that are required to design and implement risk based CBPP control program. METHODS: We randomly collected blood samples from 2,300 cattle spread across Karamoja region. Serum was extracted and screened for antibodies against Mycoplasma mycoides subsp. mycoides [Mmm] using the competitive enzyme linked immunosorbent assay [cELISA]. RESULTS: A quarter [25.4%; 95% CI: 23.7-27.3] of the screened cattle [n = 2,300] were sero-positive for Mmm. Amudat and Kaabong districts recorded the lowest [12.3%] and highest [30.7%] Mmm seroprevalence respectively. Increasing age, overnight stay in cattle kraals and location [certain districts, villages, herds and sub counties] of the cattle herds, the factors that promote animal commingling, were the most significant risk factors of seroconversion with Mmm. CONCLUSION: Results from this study indicated a higher seroprevalence of Mmm in Karamoja region cattle herds. This could be due to the increased frequency of CBPP outbreaks in recent years. To be effective, CBPP vaccination programs should target high risk herds along the international borders and other hotspot areas [e.g., parishes or sub counties] where cattle commingling is high.

Preliminary report of Mycoplasma Wenoynii and Candidatus Mycoplasma haemobos infection in Korean native cattle.

BACKGROUND: Hemotropic mycoplasmas or hemoplasmas are bacteria that attach to the erythrocyte surface and cause bovine hemoplasmosis. Two species, Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, have been identified and shown to be distributed worldwide. However, there is currently no information available on hemoplasmas in cattle in the Republic of Korea. The aim of this study was to investigate the presence of hemoplasmas in Korean native cattle and to evaluate the association between hemoplasma infection and anemia. METHODS: One farm was selected, at which blood samples were collected from 104 Korean native cattle [grazing cattle (n = 89) and housed cattle (n = 15)]. Hemoplasmas were detected via polymerase chain reaction analysis and complete blood counts were also performed. RESULTS: The overall prevalence of hemoplasmas was 34% (35/104); 20.2% (21/104) for M. wenyonii, 3.8% (4/104) for C. M. haemobos, and 9.6% (10/104) for co-infection. Candidatus Mycoplasma haemobos was detected only in grazing cattle. Of red blood cell (RBC) parameters, C. M. haemobos-infected cattle had lower RBC and hematocrit, and higher mean cell volume than hemoplasma-negative cattle, although none of these differences were statistically significant. This is the first study to report the occurrence of M. wenyonii and C. M. haemobos. Mycoplasma wenyonii is more prevalent than C. M. haemobos in Korean native cattle. The results did not show an association between hemoplasma infection and anemia. CONCLUSIONS: Considering the infection rate of hemoplasmas shown in this study, further studies, such as on the pathogenicity and clinical significance of hemoplasmas are necessary.

Unveiling genome plasticity and a novel phage in Mycoplasma felis: Genomic investigations of four feline isolates.

Mycoplasma felis has been isolated from diseased cats and horses, but to date only a single fully assembled genome of this species, of an isolate from a horse, has been characterized. This study aimed to characterize and compare the completely assembled genomes of four clinical isolates of M. felis from three domestic cats, assembled with the aid of short- and long-read sequencing methods. The completed genomes encoded a median of 759 ORFs (range 743-777) and had a median average nucleotide identity of 98.2 % with the genome of the available equid origin reference strain. Comparative genomic analysis revealed the occurrence of multiple horizontal gene transfer events and significant genome reassortment. This had resulted in the acquisition or loss of numerous genes within the Australian felid isolate genomes, encoding putative proteins involved in DNA transfer, metabolism, DNA replication, host cell interaction and restriction modification systems. Additionally, a novel mycoplasma phage was detected in one Australian felid M. felis isolate by genomic analysis and visualized using cryo-transmission electron microscopy. This study has highlighted the complex genomic dynamics in different host environments. Furthermore, the sequences obtained in this work will enable the development of new diagnostic tools, and identification of future infection control and treatment options for the respiratory disease complex in cats.

Apparent prevalence of hemotropic mycoplasma in dairy calves and replacement heifers on Michigan farms.

The bovine hemoplasmas include Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, which are increasingly recognized as infecting cattle throughout the world. Infection with hemotropic mycoplasma has been reported to be widespread in mature dairy cows, but little is known about its prevalence in calves and heifers. The objective of this study was to investigate the prevalence and dynamics of infection with M. wenyonii and C. M. haemobos in calves and replacement heifers on Michigan dairy farms and assess the potential associations between infection status and hematological values. The study was designed as a prospective cross-sectional study with a longitudinal component. A convenience sample of 11 farms agreed to participate and were visited twice between March and September 2022. During the first farm visit, researchers collected blood samples from up to 94 animals per farm distributed among newborn and preweaning calves (n ≤ 31), weaned calves (n = 21), pre-breeding heifers (n = 21), and pregnant heifers (n = 21). During the first visit, blood samples (n = 174) were also collected from a convenience sample of mature cows to confirm the herd infection status. The same calves and heifers were sampled again ∼95 d (±3.0) later. During the first visit, blood samples were collected from 797 calves and replacement heifers, whereas 675 samples were collected during the second visit due to the inability to locate some animals. Detection of M. wenyonii and C. M. haemobos was based on results of real-time PCR. The hematocrit was determined using microcentrifugation, and the concentration of leukocytes using an automated cell counter. In all herds, most mature cows that were sampled tested positive for infection. The within-herd apparent prevalence of hemoplasma in calves and replacement heifers was 100% for both M. wenyonii and C. M. haemobos. The apparent prevalence of hemoplasma in youngstock was associated with age. In calves that were 1 to 6 mo old, the prevalence of infection was 6% to 8% but sharply increased to 31% by 8 mo of age. In older animals, the prevalence remained high, and was almost 100% in animals greater than 17 mo of age. Based on calves and heifers sampled twice, the cumulative incidence varied widely among herds, ranging from 3.7% to 96.0%, and increased with the age of the animals. We found no difference in hematocrit or number of lymphocytes, monocytes, neutrophils, or total leukocytes based on infection status. The number of eosinophils was greater in infected animals. This is the first study to report the prevalence of hemoplasmas in calves and replacement heifers in the United States. It indicates that young calves can be infected with hemoplasmas, but the rate of infection is low. The likelihood of infection increases as animals age, with a notable rise in the proportion of infected heifers occurring by 8 mo old, and the prevalence eventually reaching nearly 100% in older animals. Once infected, heifers appear to remain chronic carriers. Hemoplasma infection alone does not usually lead to the development of clinical signs, and most of the animals remain apparently healthy.

Mycoplasma DnaK expression increases cancer development in vivo upon DNA damage.

Well-controlled repair mechanisms are involved in the maintenance of genomic stability, and their failure can precipitate DNA abnormalities and elevate tumor risk. In addition, the tumor microenvironment, enriched with factors inducing oxidative stress and affecting cell cycle checkpoints, intensifies DNA damage when repair pathways falter. Recent research has unveiled associations between certain bacteria, including Mycoplasmas, and various cancers, and the causative mechanism(s) are under active investigation. We previously showed that Mycoplasma fermentans DnaK, an HSP70 family chaperone protein, hampers the activity of proteins like PARP1 and p53, crucial for genomic integrity. Moreover, our analysis of its interactome in human cancer cell lines revealed DnaK's engagement with several components of DNA-repair machinery. Finally, in vivo experiments performed in our laboratory using a DnaK knock-in mouse model generated by our group demonstrated that DnaK exposure led to increased DNA copy number variants, indicative of genomic instability. We present here evidence that expression of DnaK is linked to increased i) incidence of tumors in vivo upon exposure to urethane, a DNA damaging agent; ii) spontaneous DNA damage ex vivo; and iii) expression of proinflammatory cytokines ex vivo, variations in reactive oxygen species levels, and increased ß-galactosidase activity across tissues. Moreover, DnaK was associated with increased centromeric instability. Overall, these findings highlight the significance of Mycoplasma DnaK in the etiology of cancer and other genetic disorders providing a promising target for prevention, diagnostics, and therapeutics.