Hemotropic Mycoplasmas (Hemoplasmas) in Free-Ranging Azara's Agoutis (Dasyprocta azarae) from an Urban Area of Southern Brazil

Hemotropic mycoplasmas (hemoplasmas) are opportunistic bacteria that attach to the erythrocyte surface, causing infectious anemia in several mammalian species, including rodents. Studies surveying native Azara's agoutis (Dasyprocta azarae) in Brazil are lacking. Accordingly, the present study aimed to assess hemoplasmas infection in free-ranging agoutis from an urban environmental conservation area in Curitiba, southern Brazil. Overall, 11/35 (31.43%) agoutis were positive to hemoplasmas by quantitative PCR (cycle threshold≤34.4). Sequencing of the 16S ribosomal RNA gene indicated Mycoplasma haemomuris infection, closely related to M. haemomuris subsp. ratti, suggesting hemoplasma transmission from urban rats to agoutis. Because the main route of M. haemomuris transmission has been direct rodent-to-rodent infection, the relatively lower positivity that we detected may be the result of low intraspecies contact due to the smaller social units of agoutis, generally consisting of two to four individuals, and low interspecies contact due to only sporadic agouti-rat interactions in urban settings, compared with other rodent species interactions. Further studies should be conducted to determine whether the hemoplasma infection that we found can cause clinical onset and life-threatening anemia in agoutis.

Complete Blood Counts and Blood Smear Analyses in 312 Diabetic Dogs (2007-2017)

Diabetes mellitus is a common endocrinopathy in dogs that has been associated with various biochemical changes and comorbid diseases, but hematologic abnormalities have been rarely reported. The aim of this retrospective study was to evaluate complete blood count and blood smear alterations and to describe their relationship with, and incidence of comorbid diseases in, diabetic dogs. Three-hundred twelve diabetic dogs, 286 dogs diagnosed with systemic, nondiabetic illnesses, and 506 healthy dogs were identified during the study period. Groups were compared using contingency tables and logistic regression. Associations between statistically significant complete blood count and blood smear alterations and comorbidities were evaluated using multivariable analysis. High-grade codocytosis and anisocytosis were identified more frequently in diabetic dogs, whereas high-grade reactive lymphocytosis and keratocytosis were identified less frequently (P < .001). Diabetic dogs with high-grade codocytosis had lower red blood cell, hemoglobin, hematocrit and higher white blood cell counts (P < .001). Diabetic ketoacidosis was diagnosed more frequently in diabetic dogs with high-grade codocytosis when compared with those with low-grade codocytosis (P < .001) or when compared with any other cell morphologic alterations. This study suggests that blood smear analysis should be a routine part of the evaluation of diabetic dogs.

Atypical multiple myeloma in 3 young dogs

Three dogs under 12 months old were diagnosed with atypical multiple myeloma (MM), having an aggressive multifocal anaplastic round cell sarcoma in bone marrow, viscera, and/or peripheral blood, which were confirmed by cytology and immunohistochemistry to be of plasma cell origin. The intramedullary sarcomas caused myelophthisis, osteolysis, and hypercalcemia. Complete or free light chain monoclonal gammopathy in the serum and/or urine was demonstrated by protein electrophoresis and immunofixation. The polymerase chain reaction for antigen receptor rearrangement assay performed on 2 cases identified a clonally rearranged immunoglobulin gene. Neoplastic cells lacked expression of CD45, CD3, CD18, CD21, CD34, and MHCII by flow cytometry. Immunohistochemistry revealed MUM1 immunoreactivity of the neoplastic cells. Combining all data, the diagnosis was MM. An aggressive form of MM in young dogs should be a differential diagnosis for patients with an immunoglobulin-productive, B cell-clonal, CD45-negative, MUM1-positive discrete cell neoplasm arising from the bone marrow.

Hemophagocytic syndrome associated with large granular lymphoma in an adult dog

Hemophagocytic syndrome (HPS) is a rare disorder characterized by dysregulation of the immune response resulting in uncontrolled activation of macrophages with exacerbated phagocytosis of host cells. In dogs, the criteria for diagnosis include the presence of pancytopenia or bicytopenia in the peripheral blood and >2% hemophagocytic macrophages in bone marrow aspirates. When HPS is associated with lymphoma, it is called lymphoma-associated hemophagocytic syndrome (LAHS). Here, we present a case of a 4 ½-year-old female spayed Old English Mastiff that presented with severe thrombocytopenia, mild anemia, mild to moderate leukopenia, and large granular lymphocytes (LGLs) in the peripheral blood. The patient had enlarged lymph nodes with many LGLs seen cytologically, leading to the interpretation of LGL lymphoma. Bone marrow displayed numerous LGLs that stained strongly for CD3 but did not show immunoreactivity to CD4 or CD8, and PCR for antigen receptor rearrangement analysis confirmed a clonal T-cell receptor gamma gene rearrangement. The presence of ~3.5% hemophagocytes present on the bone marrow evaluation raised concern for HPS and, more specifically, LAHS. HPS and LAHS are challenging to diagnose and require many criteria to be fulfilled before a definitive diagnosis can be made; the low number of cases in the literature makes this even more challenging in dogs. This case represents secondary LAHS due to LGL lymphoma in a dog.

A case of acute monocytic leukemia (AMoL or AML-M5) in an adult FeLV/FIV-positive cat

A 7-year-old castrated male domestic shorthair cat was presented for evaluation of decreased appetite and respiratory signs. A CBC run on presentation revealed severe nonregenerative anemia, thrombocytopenia, and leukocytosis characterized by a prominent population of blasts, having morphologic features suggestive of a monocytic lineage. The cat tested positive for FIV, FeLV, Mycoplasma haemominutum, and only mild abnormalities were identified on the chemistry panel. Bone marrow biopsies were obtained to investigate the bicytopenia and the possibility of a hematopoietic neoplasm. Although the bone marrow aspirate was nondiagnostic, the core biopsy was markedly hypercellular with a population of blasts, largely replacing the normal hematopoietic tissue. Immunohistochemical staining revealed that the blasts were CD3-negative, Pax5-negative, dimly CD18-positive, and moderately positive for Iba1. These findings, in addition to the prominent monocytic differentiation seen in peripheral blood, supported a diagnosis of acute monocytic leukemia. Palliative antiviral and antibiotic treatment and blood transfusion were performed. The patient was discharged on his fourth day of hospitalization. However, 15 days following discharge, the cat was euthanized due to the worsening of his systemic signs. This report discusses the classifications of myeloid leukemias, implications of infectious diseases in the pathogenesis of neoplasia in cats, and the use of Iba1, a "pan-monocytic/histiocytic" marker, in the diagnosis of acute leukemia.

Genomic profile of Brazilian methicillin-resistant Staphylococcus aureus resembles clones dispersed worldwide

PURPOSE

Comparative genomic analysis of strains may help us to better understand the wide diversity of their genetic profiles. The aim of this study was to analyse the genomic features of the resistome and virulome of Brazilian first methicillin-resistant Staphylococcus aureus (MRSA) isolates and their relationship to other Brazilian and international MRSA strains.

METHODOLOGY

The whole genomes of three MRSA strains previously isolated in Vitória da Conquista were sequenced, assembled, annotated and compared with other MRSA genomes. A phylogenetic tree was constructed and the pan-genome and accessory and core genomes were constructed. The resistomes and virulomes of all strains were identified.Results/Key findings. Phylogenetic analysis of all 49 strains indicated different clones showing high similarity. The pan-genome of the analysed strains consisted of 4484 genes, with 31 % comprising the gene portion of the core genome, 47 % comprising the accessory genome and 22 % being singletons. Most strains showed at least one gene related to virulence factors associated with immune system evasion, followed by enterotoxins. The strains showed multiresistance, with the most recurrent genes conferring resistance to beta-lactams, fluoroquinolones, aminoglycosides and macrolides.

CONCLUSIONS

Our comparative genomic analysis showed that there is no pattern of virulence gene distribution among the clones analysed in the different regions. The Brazilian strains showed similarity with clones from several continents.

RNA-Seq based transcriptome of whole blood from immunocompetent pigs (Sus scrofa) experimentally infected with Mycoplasma suis strain Illinois

Pigs are popular animal models in biomedical research. RNA-Seq is becoming the predominant tool to investigate transcriptional changes of the pig’s response to infection. The high sensitivity of this tool requires a strict control of the study design beginning with the selection of healthy animals to provide accurate interpretation of research data. Pigs chronically infected with Mycoplasma suis often show no obvious clinical signs, however the infection may affect the validity of animal research. The goal of this study was to investigate whether or not this silent infection is also silent at the host transcriptional level. Therefore, immunocompetent pigs were experimentally infected with M. suis and transcriptional profiles of whole blood, generated by RNA-Seq, were analyzed and compared to non-infected animals. RNA-Seq showed 55 differentially expressed (DE) genes in the M. suis infected pigs. Down-regulation of genes related to innate immunity (tlr8, chemokines, chemokines receptors) and genes containing IFN gamma-activated sequence (gbp1, gbp2, il15, cxcl10, casp1, cd274) suggests a general suppression of the immune response in the infected animals. Sixteen (29.09%) of the DE genes were involved in two protein interaction networks: one involving chemokines, chemokine receptors and interleukin-15 and another involving the complement cascade. Genes related to vascular permeability, blood coagulation, and endothelium integrity were also DE in infected pigs. These findings suggest that M. suis subclinical infection causes significant alterations in blood mRNA levels, which could impact data interpretation of research using pigs. Screening of pigs for M. suis infection before initiating animal studies is strongly recommended.

Detection of hemoplasma infection of goats by use of a quantitative polymerase chain reaction assay and risk factor analysis for infection

OBJECTIVE To develop and validate a real-time quantitative PCR (qPCR) assay for the detection and quantification of Mycoplasma ovis in goats and investigate the prevalence and risk factors for hemoplasma infection of goats located in Indiana. ANIMALS 362 adult female goats on 61 farms. PROCEDURES Primers were designed for amplification of a fragment of the dnaK gene of M ovis by use of a qPCR assay. Blood samples were collected into EDTA-containing tubes for use in total DNA extraction, blood film evaluation, and determination of PCV. Limit of detection, intra-assay variability, interassay variability, and specificity of the assay were determined. RESULTS Reaction efficiency of the qPCR assay was 94.45% (R(2), 0.99; slope, -3.4623), and the assay consistently detected as few as 10 copies of plasmid/reaction. Prevalence of infection in goats on the basis of results for the qPCR assay was 18.0% (95% confidence interval, 14% to 22%), with infected goats ranging from 1 to 14 years old, whereby 61% (95% confidence interval, 47% to 73%) of the farms had at least 1 infected goat. Bacterial load in goats infected with M ovis ranged from 1.05 × 10(3) target copies/mL of blood to 1.85 × 10(5) target copies/mL of blood; however, no bacteria were observed on blood films. Production use of a goat was the only risk factor significantly associated with hemoplasma infection. CONCLUSIONS AND CLINICAL RELEVANCE The qPCR assay was more sensitive for detecting hemoplasma infection than was evaluation of a blood film, and production use of a goat was a risk factor for infection.

Evaluation of an Electrochemical Point-of-Care Meter for Measuring Glucose Concentration in Blood from Periparturient Dairy Cattle

BACKGROUND

The Precision Xtra(®) meter is a promising low cost electrochemical point-of-care unit for measuring blood glucose concentration ([gluc]) in cattle blood. The meter uses an algorithm that assumes the intra-erythrocyte [gluc] equals the plasma [gluc] on a molal basis, and that the hematocrit is similar in humans and cattle.

OBJECTIVES

The primary objective was to determine the accuracy of the meter for measuring plasma [gluc] in dairy cattle. Secondary objectives were to characterize the influence of hematocrit and sample temperature on the measured value for [gluc].

ANIMALS

A total of 106 periparturient Holstein-Friesian cattle.

METHODS

Blood and plasma samples (1,109) were obtained and Deming regression and Bland-Altman plots were used to determine the accuracy of the meter against the reference method (plasma hexokinase assay). Multivariable regression and linear regression were used to determine the effect of hematocrit and sample temperature on the plasma [gluc] measured by the meter.

RESULTS

Intra-erythrocyte [gluc] was 18% of plasma [gluc] on a molar basis. Sample temperature had a significant linear effect on plasma [gluc] as measured by the meter for 3/5 plasma samples when measured [gluc] > 160 mg/dL.

CONCLUSIONS AND CLINICAL IMPORTANCE

The meter utilizes an algorithm that is optimized for human blood and is inaccurate when applied to bovine blood. Until a cattle-specific algorithm is developed, we recommend using plasma as the analyte instead of blood and calculating plasma [gluc] using the equation: [gluc] = 0.66 × [gluc]p-meter + 15, where [gluc]p-meter is the value reported by the meter. If blood is measured, then we recommend using the equation: [gluc] = 0.90 × [gluc]b-meter + 15.

Microscopy and genomic analysis of Mycoplasma parvum strain Indiana

Mycoplasma parvum [Eperythrozoon parvum] is the second hemotrophic mycoplasma (hemoplasma) described in pigs. Unlike M. suis, its closest phylogenetic relative, M. parvum, is considered a non-pathogenic bacterium in this host species. Natural infection of a domestic, 6-month-old splenectomized pig with M. parvum strain Indiana is described herein. Light and scanning electron microscopy of the bacteria were performed in addition to whole genome sequencing, analysis, and comparison to the genome of M. suis strain Illinois. Neither clinical signs nor anemia were observed during the infection. Microscopy analyses revealed coccoid to rod- shaped organisms varying from 0.2 to 0.5 μm; they were observed individually or in short chains by both light and electron microscopy, however less than 30% of the red blood cells were infected at peak bacteremia. The single circular chromosome of M. parvum was only 564 395 bp, smaller than M. genitalium, previously considered the tiniest member of the Mollicutes. Its general genomic features were similar to others in this class and species circumscription was verified by phylogenomic analysis. A gene-by-gene comparison between M. suis and M. parvum revealed all protein coding sequences (CDS) with assigned functions were shared, including metabolic functions, transporters and putative virulence factors. However, the number of CDS in paralogous gene families was remarkably different with about half as many paralogs in M. parvum. The differences in paralogous genes may be implicated in the different pathogenic potential of these two species, however variable gene expression may also play a role. Both are areas of ongoing investigation.

Comparative genomics and phylogenomics of hemotrophic mycoplasmas

Hemotrophic mycoplasmas (hemoplasmas) are a group of animal pathogens of the Mollicutes class. Recently, the genomes of 8 hemoplasmas have been completely sequenced. The aim of this study was to gain a better understanding of their genomic features and relationship to other Mycoplasma species. The genome structure and dynamics of hemoplasmas were analyzed by evaluating gene synteny, adaptive evolution of paralogous gene families (PGF) and horizontal gene transfer (HGT). The Mollicutes class was then phylogenetically analyzed by constructing a distance matrix of the 16S rRNA genes and a phylogenetic tree with 32 conserved, concatenated proteins. Our results suggest that the hemoplasmas have dynamic genomes. The genome size variation (from 547 to 1,545 genes) indicates substantial gene gain/loss throughout evolution. Poorly conserved gene syntenies among hemoplasmas, positional shuffling of paralogous genes between strains, HGT, and codons under positive selection in PGFs were also observed. When compared to other Mollicutes species, the hemoplasmas experienced further metabolic reduction, and the 16S rRNA gene distance matrix of the available mollicutes suggests that these organisms presently constitute the most divergent clade within its class. Our phylogenetic tree of concatenated proteins showed some differences when compared to the 16S rRNA gene tree, but non-mycoplasma organisms, such as Ureaplasma spp. and Mesoplasma spp., continue to branch within Mycoplasma clades. In conclusion, while the hemoplasmas experienced further metabolic shrinkage through gene loss, PGFs with positively selected codons are likely beneficial to these species. Phylogeny of the mollicutes based on 16S rRNA genes or concatenated proteins do not obey the current taxonomy. The metabolism and genetic diversity of the mollicutes, the presence of HGT, and lack of standard for genus circumscription are likely to hinder attempts to classify these organisms based on phylogenetic analyses.

Identification of Mycoplasma suis antigens and development of a multiplex microbead immunoassay

The aims of the current study were to identify Mycoplasma suis antigens and develop a multiplex microbead immunoassay (MIA). A M. suis-expression library was screened for immunogens using sera from infected pigs. Based on bioinformatics, putative antigens were identified within positive inserts; gene fragments were expressed and purified as polyhistidine fusion proteins, and immunoreactivity was confirmed by Western blot. Selected antigens were used to develop a MIA. Sera from noninfected and infected pigs were used to set the median fluorescent intensity (MFI) cutoffs and as positive controls, respectively. Assay specificity was tested using sera from pigs seropositive for other pathogens (2 different pigs seropositive for each pathogen). Samples from 51 field pigs and 2 pigs during the course of acute (pig 1) and chronic (pig 2) infections were tested using MIA, indirect hemagglutination assay (IHA), and quantitative polymerase chain reaction (qPCR). Sixteen reactive plaques (52 genes) were detected. A heat-shock protein (GrpE), a nicotinamide adenine dinucleotide-dependent glyceraldehyde 3-phosphate dehydrogenase (GAPN), and 4 proteins from paralogous gene families (PGFs) were identified as antigens by Western blot. While GrpE, GAPN, and 1 PGF protein were strong antigens, the others were not suitable as MIA targets. A MIA using GrpE, GAPN, and the strongly reactive PGF protein was developed. Cross-reactivity with sera from pigs infected with Mycoplasma hyopneumoniae, Porcine circovirus-2, Porcine parvovirus, Porcine reproductive and respiratory syndrome virus, and Porcine respiratory coronavirus with this MIA was not observed. Pig 2 was consistently positive by MIA and qPCR, whereas pig 1, initially negative, seroconverted before becoming qPCR positive. Only 2 samples (from pig 1) were IHA positive. Five (9.8%) field samples were qPCR positive and 40 (78.43%) were positive for all 3 MIA antigens; however, all were IHA negative. In summary, the MIA is specific and more sensitive than qPCR and IHA, providing simultaneous evaluation of antibody response to M. suis antigens.

Mycoplasma haemocanis--the canine hemoplasma and its feline counterpart in the genomic era

Mycoplasma haemocanis is a hemotrophic mycoplasma (hemoplasma), blood pathogen that may cause acute disease in immunosuppressed or splenectomized dogs. The genome of the strain Illinois, isolated from blood of a naturally infected dog, has been entirely sequenced and annotated to gain a better understanding of the biology of M. haemocanis. Its single circular chromosome has 919 992 bp and a low G + C content (35%), representing a typical mycoplasmal genome. A gene-by-gene comparison against its feline counterpart, M. haemofelis, reveals a very similar composition and architecture with most of the genes having conserved synteny extending over their entire chromosomes and differing only by a small set of unique protein coding sequences. As in M. haemofelis, M. haemocanis metabolic pathways are reduced and apparently rely heavily on the nutrients afforded by its host environment. The presence of a major percentage of its genome dedicated to paralogous genes (63.7%) suggests that this bacterium might use antigenic variation as a mechanism to evade the host’s immune system as also observed in M. haemofelis genome. Phylogenomic comparisons based on average nucleotide identity (ANI) and tetranucleotide signature suggest that these two pathogens are different species of mycoplasmas, with M. haemocanis infecting dogs and M. haemofelis infecting cats.

Identification of a Mycoplasma ovis-like organism in a herd of farmed white-tailed deer (Odocoileus virginianus) in rural Indiana

Mycoplasma ovis is a hemoplasma parasite of sheep, goats, and reindeer; however, natural hemoplasma infection in white-tailed deer has not previously been reported. Subsequent to finding many coccoid, bacillary, and ring-shaped organisms, consistent with hemotropic mycoplasmas, on RBCs from a 72-day-old female white-tailed fawn, we sought to (1) identify the putative hemoplasma observed in blood from the fawn, (2) evaluate others in the herd for hemoplasma infection, and (3) identify clinicopathologic characteristics of hemoplasma-infected white-tailed deer. EDTA-anticoagulated whole blood was collected from the fawn and 8 apparently healthy does in the same herd. CBCs were performed on 7 nonclotted samples from the fawn and 6 does. DNA was extracted from all samples, followed by PCR amplification of bacterial (16S rDNA) and protozoal (18S rDNA) genes. The nearly complete 16S rDNA product from the fawn's sample was directly sequenced and compared with known sequences in the GenBank database. Samples from the fawn and 7 of 8 does were PCR-positive using hemoplasma-specific and M ovis-specific protocols. The fawn was PCR-negative for Anaplasma spp., Babesia spp., and Theileria spp. The 16S rDNA sequence from the fawn (GenBank accession number, FJ824847) was most closely related to M ovis (AF338268), having 98.5% sequence identity. The fawn had a mild nonregenerative anemia, a neutrophilic left-shift with toxic change, aspiration bronchopneumonia, and gastrointestinal disease. Hematologic values, including blood film evaluation, in infected does were unremarkable. The M ovis-like organism may have acted as either an opportunistic or primary pathogen in the fawn. The high occurrence of subclinical infections in the does suggests that white-tailed deer may act as wildlife reservoirs for M ovis.

Genome of Mycoplasma haemofelis, unraveling its strategies for survival and persistence

Mycoplasma haemofelis is a mycoplasmal pathogen (hemoplasma) that attaches to the host's erythrocytes. Distributed worldwide, it has a significant impact on the health of cats causing acute disease and, despite treatment, establishing chronic infection. It might also have a role as a zoonotic agent, especially in immunocompromised patients. Whole genome sequencing and analyses of M. haemofelis strain Ohio2 was undertaken as a step toward understanding its survival and persistence. Metabolic pathways are reduced, relying on the host to supply many of the nutrients and metabolites needed for survival. M. haemofelis must import glucose for ATP generation and ribose derivates for RNA/DNA synthesis. Hypoxanthine, adenine, guanine, uracil and CMP are scavenged from the environment to support purine and pyrimidine synthesis. In addition, nicotinamide, amino acids and any vitamins needed for growth, must be acquired from its environment. The core proteome of M. haemofelis contains an abundance of paralogous gene families, corresponding to 70.6% of all the CDSs. This "paralog pool" is a rich source of different antigenic epitopes that can be varied to elude the host's immune system and establish chronic infection. M. haemofelis also appears to be capable of phase variation, which is particularly relevant to the cyclic bacteremia and persistence, characteristics of the infection in the cat. The data generated herein should be of great use for understanding the mechanisms of M. haemofelis infection. Further, it will provide new insights into its pathogenicity and clues needed to formulate media to support the in vitro cultivation of M. haemofelis.

A quantitative TaqMan PCR assay for the detection of Mycoplasma suis

AIM

To develop a TaqMan probe-based, highly sensitive and specific quantitative PCR (qPCR) assay for the detection and quantification of Mycoplasma suis in the blood of pigs.

METHODS AND RESULTS

Primers and probes specific to Myc. suis 16S rRNA gene were designed. The qPCR assay's specificity, detection limit, intra- and inter-assay variability were evaluated and its performance was compared with a Myc. suis conventional PCR assay (cPCR). Blood of two experimentally infected pigs, 40 Indiana pigs, 40 Brazilian sows and 28 peccaries were tested. The assay detected as few as ten copies of Myc. suis plasmids and was 100-fold more sensitive than the cPCR. No cross-reactivity with nontarget pig mycoplasmas was observed. An average of 1·62 × 10(11) and 2·75 × 10(8) target copies ml(-1) of blood were detected in the acutely and chronically infected pigs, respectively. Three (7·5%) pigs and 32 (80·0%) sows were positive while all peccaries were negative for Myc. suis.

CONCLUSION

The developed qPCR assay is highly sensitive and specific for Myc. suis detection and quantification.

SIGNIFICANCE AND IMPACT OF THE STUDY

TaqMan qPCR is an accurate and quick test for detection of Myc. suis infected pigs, which can be used on varied instrumentation platforms.

Complete genome sequence of Mycoplasma suis and insights into its biology and adaption to an erythrocyte niche

Mycoplasma suis, the causative agent of porcine infectious anemia, has never been cultured in vitro and mechanisms by which it causes disease are poorly understood. Thus, the objective herein was to use whole genome sequencing and analysis of M. suis to define pathogenicity mechanisms and biochemical pathways. M. suis was harvested from the blood of an experimentally infected pig. Following DNA extraction and construction of a paired end library, whole-genome sequencing was performed using GS-FLX (454) and Titanium chemistry. Reads on paired-end constructs were assembled using GS De Novo Assembler and gaps closed by primer walking; assembly was validated by PFGE. Glimmer and Manatee Annotation Engine were used to predict and annotate protein-coding sequences (CDS). The M. suis genome consists of a single, 742,431 bp chromosome with low G+C content of 31.1%. A total of 844 CDS, 3 single copies, unlinked rRNA genes and 32 tRNAs were identified. Gene homologies and GC skew graph show that M. suis has a typical Mollicutes oriC. The predicted metabolic pathway is concise, showing evidence of adaptation to blood environment. M. suis is a glycolytic species, obtaining energy through sugars fermentation and ATP-synthase. The pentose-phosphate pathway, metabolism of cofactors and vitamins, pyruvate dehydrogenase and NAD⁺ kinase are missing. Thus, ribose, NADH, NADPH and coenzyme A are possibly essential for its growth. M. suis can generate purines from hypoxanthine, which is secreted by RBCs, and cytidine nucleotides from uracil. Toxins orthologs were not identified. We suggest that M. suis may cause disease by scavenging and competing for host' nutrients, leading to decreased life-span of RBCs. In summary, genome analysis shows that M. suis is dependent on host cell metabolism and this characteristic is likely to be linked to its pathogenicity. The prediction of essential nutrients will aid the development of in vitro cultivation systems.

[Use of Southern Blot/Hybridization technique associated to polymerase chain reaction to improve the sensitivity in the diagnosis of hemoplasma infections in domestic cats]

The aim of this study was to determine whether Southern Blot/Hybridization (SB) associated to Polymerase Chain Reaction (PCR) improves the sensitivity in the detection of hemoplasma DNA in domestic cats (Felis catus). Whole blood was collected in tubes containing the anticoagulant ethylenediamine tetra-acetic acid and DNA extracted from 149 animals. PCR was performed using species specific primers to amplify the 16S ribosomal RNA subunit of Mycoplasma haemofelis and 'Candidatus M. haemominutum' from these samples. Hybridization was performed using a 16S rDNA probes chemically labeled and the results were visualized using a chemiluminescent substrate addition followed by autoradiography. Eighteen (12.1%) of the 149 tested samples had a positive PCR result for hemoplasma species DNA. SB/hybridization technique showed that 24/149 (16.1%) samples were positive for hemoplasmas, confirming the 18 PCR-positive results and reveling six additional positive animals (p<0.001). SB/hybridization method with specific probes was more sensitive than PCR performed alone, being complimentary to this technique to diagnose infections caused by feline hemoplasmas.

Brucella canis endophthalmitis in 3 dogs: clinical features, diagnosis, and treatment

OBJECTIVE

To describe historical, clinical and diagnostic features of dogs with Brucella canis endophthalmitis and the response to medical therapy.

ANIMALS STUDIED

Three dogs with naturally acquired B. canis endophthalmitis.

PROCEDURE

Dogs were treated symptomatically with topical ophthalmic anti-inflammatories and a novel antimicrobial protocol that included doxycycline, enrofloxacin, rifampin and streptomycin.

RESULTS

All dogs presented with chronic or recurrent uveitis in the absence of overt systemic disease. Clinical ophthalmologic abnormalities were unilateral in each dog and included mild-to-moderate anterior uveitis, iris hyperpigmentation, marked vitreal infiltrates, and multifocal chorioretinitis. Dogs were diagnosed with canine brucellosis serologically and by blood culture (n = 2 dogs) or polymerase chain reaction of aqueous humor and blood (n = 1 dog). Active ocular inflammation resolved in all dogs during treatment, with preservation of vision in 2 dogs. Following treatment, B. canis could not be cultured from blood samples and serological values declined with seronegativity achieved in all dogs after a median of 96 weeks (range: 36-112 weeks) of therapy.

CONCLUSIONS

Brucella canis infection should be included in the differential diagnosis for dogs with intraocular inflammation, regardless of previous history or neuter status. This is the first report of apparently successful medical therapy of canine brucellosis with ocular involvement.

Chronic myelogenous leukemia in a great horned owl (Bubo virginianus)

A free-ranging adult female great horned owl (Bubo virginianus) was presented to the Wildlife Medical Clinic at the University of Illinois after being observed with anorexia and decreased activity. A severe leukocytosis (212 400 cells/microl), primarily comprised of mature heterophils, was found at presentation. Results of various diagnostic tests including radiographs, Chlamydophila serologic testing, measurement of Aspergillus antibody and antigen titers, plasma protein electrophoresis, fecal culture and acid-fast staining, coelioscopy, endoscopy, tracheoscopy, exploratory coelomotomy, nuclear scintigraphy, tissue cultures, bone marrow biopsy, and histopathology revealed no underlying cause for the persistent leukocytosis. No response to treatment with antibiotics or antifungal agents was observed, although a transient, significant decrease in the leukocyte count (6200 cells/microl) was observed after treatment with fenbendazole. A presumptive diagnosis of chronic myelogenous leukemia was made based on 3 factors: disease duration of greater than 3 months, a lack of identifiable foci of inflammation, and a lack of response to conventional therapy. The diagnosis was confirmed based on postmortem examination and testing 177 days after initial presentation.

Design, optimization, and application of a conventional PCR assay with an internal control for detection of 'Candidatus Mycoplasma turicensis' 16S rDNA in domestic cats from Brazil

BACKGROUND

'Candidatus Mycoplasma turicensis' (CMtc) is a hemotrophic bacterial species that can, alone or in combination, induce anemia in cats. The diagnostic test of choice for hemoplasma infections is PCR. Conventional PCR assays have been developed for the detection of Mycoplasma haemofelis (Mhf) and 'Candidatus M. haemominutum' (CMhm) but not for CMtc. Although real-time PCR assays have been reported for all of the feline hemoplasmas, the expense of necessary instrumentation precludes its use in Brazil and many other countries.

OBJECTIVES

The goals of this study were to develop and optimize a conventional PCR assay to diagnose CMtc using an internal control to detect false-negative results, and to evaluate the occurrence of CMtc infection in domestic cats from Brazil.

METHODS

Species-specific primers were designed and a PCR assay was developed for the detection of CMtc 16S rDNA in cat blood. Sensitivity was determined by serial 10-fold dilutions of plasmid and DNA extracted from blood from an experimentally infected cat. EDTA blood samples from 373 cats were collected. DNA was extracted using a silica-based protocol and tested using the PCR assay.

RESULTS

Primer concentration, annealing temperature, and MgCl(2) concentration were optimized in the presence and absence of the internal control. Two samples negative for the internal control were excluded. Of the remaining 371 samples (117 healthy and 254 unhealthy cats), 17 (4.6%) were positive for CMtc.

CONCLUSION

These results demonstrate the utility of an optimized PCR assay to detect CMtc in feline blood samples. We also report for the first time the prevalence of CMtc infection in domestic cats in Brazil.

Hemoplasma infection in HIV-positive patient, Brazil

Hemotrophic mycoplasmas infect a variety of mammals. Although infection in humans is rarely reported, an association with an immunocompromised state has been suggested. We report a case of a Mycoplasma haemofelis–like infection in an HIV-positive patient co-infected with Bartonella henselae.

Prevalence and risk factors for hemoplasmas in domestic cats naturally infected with feline immunodeficiency virus and/or feline leukemia virus in Rio de Janeiro--Brazil

The aim of this study was to determine the prevalence and risk factors for Mycoplasma haemofelis (Mhf) and 'Candidatus Mycoplasma haemominutum' (Mhm) infections in domestic cats tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Based on serological testing, cats were grouped as i) FIV-positive (n=25); ii) FeLV-positive (n=39); iii) FIV/FeLV-positive (n=8); and iv) FIV/FeLV-negative (n=77). Complete blood counts were followed by DNA extraction, species-specific polymerase chain reaction (16S rRNA gene) for Mhf and Mhm and Southern blotting for all animals. Mhf DNA was found in 4.0, 2.6, 12.5 and 7.8% of the cats from groups i, ii, iii and iv, respectively, while 32, 5.1, 50 and 5.2% of these animals had an Mhm infection. Cats with FIV (OR=4.25, P=0.009) and both FIV and FeLV (OR=7.56, P=0.014) were at greater risk of being hemoplasma infected than retroviral-negative cats, mainly due to Mhm infection (OR=8.59, P=0.001 and OR=18.25, P=0.001, respectively). Among pure-breed cats, FIV-positive status was associated with hemoplasma infection (OR 45.0, P=0.001).

Acute granulocytic ehrlichiosis in a rottweiler

Acute granulocytic ehrlichiosis was identified in a 6-year-old rottweiler that was presented for possible pancreatitis. Intracytoplasmic inclusion bodies were identified within neutrophils on a peripheral blood smear. Serology was ineffective in identifying the disease in the acute state. The diagnosis and identification of the organism were confirmed by polymerase chain reaction (PCR) and deoxyribonucleic acid (DNA) sequencing. Based on elevations in amylase and lipase and the presence of right cranial-quadrant abdominal pain, concurrent pancreatitis was diagnosed. It is unknown if there was any association between the acute granulocytic ehrlichiosis and the pancreatitis. The dog recovered well following doxycycline therapy.

Co-infection with Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' in three cats from Brazil

The two most common haemotropic Mycoplasma of cats, Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' have been identified using molecular techniques in all continents, except Antarctica. We report the first molecular characterization in South America of a dual infection with M haemofelis and 'Candidatus Mycoplasma haemominutum' in three domestic cats. The 16S ribosomal RNA gene was amplified in three anaemic cats in which haemoplasma organisms were seen attached to the erythrocytes in the peripheral blood smear. Bands of the expected size for M haemofelis and 'Candidatus Mycoplasma haemominutum' were observed in all three cats. The 393 bp segment of one of the amplicons had a similarity value of 100% to M haemofelis, whereas the other amplicon, a 192 bp segment, was 100% similar to 'Candidatus Mycoplasma haemominutum'. After diagnosis, two cats received blood transfusion and they were all treated with doxycycline. All three cats recovered uneventfully.

Molecular detection of "Candidatus Mycoplasma haemominutum" in a lion (Panthera leo) from a brazilian zoological garden

Although Mycoplasma haemofelis and "Candidatus Mycoplasma haemominutum" infections have been reported in wild cats from United States, their presence among native and captive wild cats in Brazil is still unknown. A 12 year old healthy male lion (Panthera leo) from the Zoological Garden of Curitiba, Brazil was anesthetized for transportation and dental evaluation. A blood sample was obtained for a complete blood cell count (CBC) and PCR analysis. DNA was extracted and fragments of Mycoplasma haemofelis and "Candidatus Mycoplasma haemominutum" 16S ribosomal RNA gene were amplified in PCR assays. CBC results were within reference intervals. A weak band of 192 pb for "Candidatus Mycoplasma haemominutum" was observed, and no band was amplified from Mycoplasma haemofelis reaction. A weak PCR band associated with normal CBC results and without visible parasitemia or clinical signs may suggest a chronic subclinical infection with "Candidatus Mycoplasma haemominutum". The lack of clinical signs may also represent the low pathogenicity of this organism; however, it is noteworthy that immune suppression caused by management and/or corticoids treatment may induce parasitemia and anemia in this animal. This detection suggests further studies in captive wild cats in Brazilian Zoological Gardens.

Exploratory study of Mycoplasma suis (Eperythrozoon suis ) on four commercial pig farms in southern Brazil

Mycoplasma suis (Eperythrozoon suis) was detected by PCR and Southern blot in 186 pigs (121 sows, 61 piglets and four boars) on four farms in southern Brazil. DNA was extracted from blood samples and a 16S rRNA gene fragment of M suis was amplified by PCR; Southern blot analysis was then performed on all the samples. Twenty-two of the sows (18.2 per cent) were positive by PCR, and 40 (33.1 per cent) were positive by Southern blot; only one piglet and one boar were positive. The packed cell volume and total plasma protein of the pigs and their PCR and Southern blot results were not significantly different on the four farms, but higher proportions of the pigs were positive by Southern blot than by PCR (P<0.05). The packed cell volume and total plasma protein concentrations of the M suis positive and negative sows were not significantly different.

Babesia gibsoni genotype Asia in dogs from Brazil

Babesia gibsoni was first recognized in India in 1910. Analysis of 18S rRNA has shown that there are at least three distinct isolates that are morphologically identical. Although organisms similar to B. gibsoni have been identified in peripheral blood smears from one dog in Brazil, this isolate has not been molecularly characterized. Accordingly, we obtained blood samples from 16 dogs with intraerythrocytic inclusion bodies. DNA was extracted and amplified with primers that detect a segment of the 18S rRNA gene of the Babesia genus. Amplicons of the expected size for B. gibsoni were observed in 4 of the 16 dogs. The sequence of the 18S rRNA yield a 460 base pair segment that had a 99% homology with the B. gibsoni genotype Asia 1. Our findings suggest that the small piroplasm that naturally infects dogs in Brazil is B. gibsoni genotype Asia.

Mycoplasma haemolamae infection in a 4-day-old cria: support for in utero transmission by use of a polymerase chain reaction assay

Blood smear examination in a 4-day-old alpaca revealed massive erythrocyte parasitism by Mycoplasma haemolamae. Blood collected from both the nonparasitemic dam and the cria were positive for M. haemolamae by polymerase chain reaction (PCR) analysis. These findings suggest in utero transmission of M. haemolamae in camelids, even when the dam is not parasitemic.

Can we continue research in splenectomized dogs? Mycoplasma haemocanis: old problem--new insight

We report the appearance of a Mycoplasma haemocanis infection in laboratory dogs, which has been reported previously, yet, never before in Europe. Outbreak of the disease was triggered by a splenectomy intended to prepare the dogs for a hemorrhagic shock study. The clinical course of the dogs was dramatic including anorexia and hemolytic anemia. Treatment included allogeneic transfusion, prednisone, and oxytetracycline. Systematic follow-up (n = 12, blood smears, antibody testing and specific polymerase chain reaction) gives clear evidence that persistent eradication of M. haemocanis is unlikely. We, therefore, had to abandon the intended shock study. In the absence of effective surveillance and screening for M. haemocanis, the question arises whether it is prudent to continue shock research in splenectomized dogs.

Anemia Associated With ’Candidatus Mycoplasma haemominutum’ in a Feline Leukemia Virus-Negative Cat With Lymphoma

’Candidatus Mycoplasma haemominutum,’ previously known as the small form of Haemobartonella felis (California species), is a hemotrophic parasite found on erythrocytes of infected cats. Although fleas are potential vectors, confirmatory studies are lacking. Healthy cats infected with ’Candidatus Mycoplasma haemominutum’ generally do not have clinically significant anemia, but concurrent disease or immune suppression may predispose a cat to develop a life-threatening anemia, such as in the case reported here.

Mycoplasma haemocanis infection--a kennel disease?

Mycoplasma haemocanis (formerly Haemobartonella canis) is a red blood cell parasite that causes disease mainly in immunosuppressed and splenectomized dogs. Clinical outbreak of the disease resulted in failure of a large experimental project. We aimed to identify whether M. haemocanis has increased prevalence in kennel-raised dogs. In a prospective study, we compared the prevalence of M. haemocanis in whole blood (anti-coagulated by use of EDTA) collected from pet dogs (University of Illinois, Urbana Champaign, Ill.; n = 60) with that in blood from dogs raised in three distinct kennels in western Europe (WE; n = 23), eastern Europe (EE; n = 20), and North America (NA; n = 20). Screening included antibody testing and microscopy of blood smears. The presence of M. haemocanis was identified using a polymerase chain reaction (PCR) assay for specific DNA of the organism. None of the pet dogs (0%) was test positive for M. haemocanis DNA. Mycoplasma haemocanis was found in dogs tested at all of the kennels. Infection rate in the three kennels was 30, 35, and 87%, respectively (all P < 0.001 versus control, chi2-test). Latent infection with M. haemocanis was not a single observation in kennel-raised dogs. Prevalence may be higher than that in a pet dog population. The potential exists for these latent infections to adversely affect or confound research results.

Hemotrophic mycoplasmas (hemoplasmas): a review and new insights into pathogenic potential

The red cell parasites formerly known as Haemobartonella and Eperythrozoon spp have been reclassified as hemotrophic mycoplasmas (hemoplasmas) based on strong phylogenetic evidence and 16S ribosomal RNA gene sequences. The latter form the basis for polymerase chain reaction assays used to detect infection. Candidatus designation was given to incompletely characterized species. Like other mycoplasmas, hemoplasmas are small epicellular parasites that lack a cell wall and are susceptible to tetracyclines; their circular, double-stranded DNA encodes only those gene products essential for life. Diseases caused by infection with hemoplasmas range from overt life-threatening hemolytic anemia to subtle chronic anemia, ill-thrift, and infertility. In addition, the organisms may act as cofactors in the progression of retroviral, neoplastic, and immune-mediated diseases. Intimate contact of hemoplasma organisms with RBCs leads to cell injury through immune-mediated and other mechanisms that have not yet been defined. Despite an intense immune response and even with antibiotic treatment, infected animals probably remain chronic carriers after clinical signs have resolved.

New perspectives about Hemotrophic mycoplasma (formerly, Haemobartonella and Eperythrozoon species) infections in dogs and cats

The new perspectives about hemotrophic mycoplasma infections in cats and dogs can be summarized as follows: Haemobartonella and Eperythrozoon species infecting the dog and cat have been reclassified as mycoplasmal parasites and given the names M haemofelis (Ohio or large form of H felis), M haemominutum (California or small form of H felis), and M haemocanis (H canis). The prevalence of hemotrophic mycoplasma infections in anemic cats in the United States is about 25% and usually involves M haemofelis. However, nonanemic cats may also be infected most commonly with M haemominutum. Chronic infections with hemotrophic mycoplasmas may promote myeloproliferative disorders in FeLV-infected cats. M haemocanis infection in dogs may be a widespread latent disease in kennel-raised dogs and is being investigated. The PCR assay is exquisitely sensitive for detection of M haemofelis and M haemominutum, and testing of blood donor cats and perhaps dogs should be done regularly. Fleas are involved in the transmission of M haemofelis to the cat, whereas R sanguines may be involved with transmission of M haemocanis to the dog. Treatment with doxycycline effectively controls acute infection in the cat and dog, and enrofloxacin may also be effective in the cat, but none of the antibiotics tested to date consistently clears the parasites.

Physical map and genome sequencing survey of Mycoplasma haemofelis (Haemobartonella felis)

Mycoplasma haemofelis is an uncultivable red-cell pathogen of cats. Isolated M. haemofelis DNA was used to create a bacterial artificial chromosome library and physical map. Random sequencing of this material revealed 75 genes that had not been previously reported for M. haemofelis or any other hemotrophic mycoplasma.

Identification of Haemobartonella felis (Mycoplasma haemofelis) in captive nondomestic cats

This study was undertaken to determine whether Haemobartonella felis (Mycoplasma haemofelis), the causative bacterial agent of feline infectious anemia, infects nondomestic cats. Routine complete blood count and polymerase chain reaction (PCR) were performed to detect the gene for 16S ribosomal RNA for the organism. Sixty-four blood samples were collected from 54 nondomestic cats, including tigers (Panthera tigris), cheetahs (Acinonyx jubatus), lions (P. leo), mountain lions (Felis concolor), snow leopards (P. unica), and a jaguar (P. onca). Some cats were sampled on two or three different dates. Two tigers were positive for H. felis by PCR analysis. As previously described in domestic cats, the parasitemia appears to be intermittent in nondomestic cats.

'Candidatus mycoplasma haemodidelphidis' sp. nov., 'Candidatus mycoplasma haemolamae' sp. nov. and Mycoplasma haemocanis comb. nov., haemotrophic parasites from a naturally infected opossum (Didelphis virginiana), alpaca (Lama pacos) and dog (Canis familiaris): phylogenetic and secondary structural relatedness of their 16S rRNA genes to other mycoplasmas

The 16S rRNA sequence of newly characterized haemotrophic bacteria in an opossum (Didelphis virginiana) and alpaca (Lama pacos) was determined. In addition, the 16S rRNA sequence of a haemotrophic parasite in the dog (Canis familiaris) was determined. Sequence alignment and evolutionary analysis as well as secondary structural similarity and signature nucleotide sequence motifs of their 16S rRNA genes, positioned these organisms in the genus Mycoplasma. The highest scoring sequence similarities were 16S rRNA genes from haemotrophic mycoplasma species (Haemobartonella and Eperythrozoon spp.). However, the lack of several higher-order structural idiosyncrasies used to define the pneumoniae group, suggests that these organisms and related haemotrophic mycoplasmas represent a new group of mycoplasmas. It is recommended that the organisms be named 'Candidatus Mycoplasma haemodidelphidis', 'Candidatus Mycoplasma haemolamae' and Mycoplasma haemocanis comb. nov., to provide some indication of the target cell and host species of these parasites, and to reflect their phylogenetic affiliation.

Use of a polymerase chain reaction assay for detection of Haemobartonella canis in a dog

A polymerase chain reaction (PCR) originally developed for detection of Haemobartonella felis in cats was successfully used for detection of H canis in an 8-year-old spayed Great Dane. The dog had been splenectomized and was undergoing immunosuppressive chemotherapy at the time of diagnosis. Sequence analysis of the 16S ribosomal RNA gene revealed that the Haemobartonella spp infecting this dog was 97% homologous to the sequence previously reported for the Ohio strain of H felis. Clinical and hematologic abnormalities as well as identification of the organisms by use of light and electron microscopy supported the diagnosis of H canis. The PCR assay used for detection of H felis may be useful for the detection of H canis in dogs prior to blood donation, splenectomy, or treatment with immunosuppressive drugs.