KPC-2-producing Pseudomonas aeruginosa isolated from wild animals in Brazil.

Pseudomonas aeruginosa an opportunistic pathogen that causes infections in hospitals and has high morbidity and mortality rates. In addition, it is a widely distributed environmental bacterium that can colonise a variety of habitats. Although wild animals do not have access to antibiotics, antibacterial resistance in these animals has increasingly been reported worldwide. Although the presence of Klebsiella pneumoniae carbapenemase (KPC) is uncommon in P. aeruginosa, it has been increasingly reported. This study examined KPC-2-producing P. aeruginosa in wild animals. A total of 27 P. aeruginosa isolates were obtained from clinical cases treated at the Microbiology Laboratory of the Veterinary Hospital of UFMT, Brazil. P. aeruginosa and blaKPC-2 carbapenemase resistance genes were identified using PCR. Antimicrobial susceptibility of KPC-producing P. aeruginosa was evaluated using the disk diffusion method. The blaKPC-2 gene was detected in 40.7% of the isolates (11/27). The rates of antimicrobial resistance and intermediate sensitivity were as follows: piperacillin/tazobactam (44.4%), imipenem (29.6%), meropenem (51.8%), amikacin (77.8%), cefepime (85.2%), and ciprofloxacin (70.4%). Twelve isolates were classified as Multidrug-resistant (MDR). This study presents the first report of P. aeruginosa with the blaKPC-2 gene in wild animals in Brazil, highlighting the importance of molecular research on resistance genes in P. aeruginosa from a One-Health perspective.

Molecular detection and genetic characterization of Ehrlichia canis and Ehrlichia sp. in neotropical primates from Brazil.

The Anaplasmataceae family includes obligate, arthropod-transmitted intracellular bacteria that can be zoonotic and potentially fatal. Studies focusing on the interaction between neotropical primates and the agents of this family are scarce. The present study aimed to identify agents of the Anaplasmataceae family in the whole blood of free-living and captive neotropical primates in the State of Mato Grosso, Central-West Brazil. Thirty-eight samples of six nonhuman primate (NHP) species were collected in seven municipalities and analysed through polymerase chain reaction (PCR), nucleotide sequencing, and phylogenetic analysis of the dsb, groEL, 16S rRNA, and gltA genes. DNA fragments similar to those of Ehrlichia canis were detected in Sapajus apella and Ehrlichia chaffeensis from Mico melanurus. The sequences generated in this study and homologous sequences retrieved from GenBank® were used for phylogenetic analyses to characterize the Ehrlichial agents detected in NHPs. The agents were then grouped into clades corresponding to different isolates from the NHP species. In addition, an Anaplasma sp. closely related to Anaplasma marginale was identified in two S. apella individuals. These findings shed light on the susceptibility of neotropical NHPs to Anaplasmataceae agents. These bacteria are known to be transmitted by ticks, which can also serve as possible sources of infection for other animals, including humans.

Determination of multidrug-resistant populations and molecular characterization of complex Klebsiella spp. in wild animals by multilocus sequence typing.

Background and Aim: One of the most significant public health concerns is multidrug-resistant (MDR) microorganisms. Klebsiella spp. have been at the forefront of causing different types of infections such as bacteremia, urinary tract infections, pneumonia, enteritis, and sepsis in humans as well as animals. This study aimed to determine the genomic similarity between Klebsiella spp. isolated from wild animal samples and those described in the Institut Pasteur genomic database to verify the spread of resistant clones regionally in the state of Mato Grosso, and to compare the epidemiological data in different regions of Brazil and the world. Materials and Methods: Isolates from various sites of injury in wild animals were identified by sequencing the 16S rRNA gene. Antimicrobial susceptibility testing was performed using the disk diffusion method to verify the resistance profile, and then, multilocus sequence typing was performed to verify the population structure and compare the isolates from other regions of Brazil and the world. Results: Twenty-three sequence types (STs) were observed; of these, 11 were new STs, as new alleles were detected. There was no predominant ST among the isolates. All isolates were MDR, with high rates of resistance to sulfonamides, ampicillin, amoxicillin, and nitrofurantoin and low resistance to meropenem, imipenem, and amikacin. Conclusion: Improving our understanding of the population structure of Klebsiella spp. in wild animals may help determine the source of infection during outbreaks in humans or animals, as the One Health concept emphasizes the interlinks between humans, animals, and environmental health.

Genotyping of rabies positive samples isolated from animals in Mato Grosso and Rondônia - Brazil.

Lyssavirus is a genus that causes infectious disease transmit by bats transmit, which results in economic losses in livestock and public health problems. From 2005 to 2019, more than 49 thousand cases of the disease were registered in animals in Brazil, with 3418 registered in Mato Grosso (MT). The lack of information on the genetic diversity and distribution of the rabies virus in MT was the motivation for carrying out this study. A total of 117 samples of brain tissue from cattle, horses, donkeys, mules and sheep from 29 municipalities in the state of MT and one municipality in Rondônia were used. Direct immunofluorescence and/or biological tests performed from 2014 to 2021 indicated that all samples were positive for the disease. RNA was extracted and molecular analysis was performed using RT-PCR for the N gene. Of the 117 samples analyzed, 50 were amplified by RT-PCR, purified and sequenced. The samples showed 93.13%-100% identity with the rabies virus. The sequences were submitted to phylogenetic analysis that resulted in a tree of four clades; these were genetically grouped into distinct regions within the Desmodus rotundus lineage. The results of the geolocation of clades will be useful to guide monitoring, control and health surveillance programs in MT.

Molecular detection of Toxoplasma gondii and Neospora caninum in neotropical primates.

BACKGROUND: Toxoplasma gondii and Neospora caninum infections in primates are potentially fatal and directly impact the conservation of these animals and public health. MATERIALS AND METHODS: A total of 38 blood/clot samples collected from free-living and captive neotropical primates undergoing clinical care or found dead by environmental authorities in the Mato Grosso State, Brazil, were analyzed by PCR for DNA detection of T. gondii and N. caninum. Furthermore, eight animals were submitted to immunohistochemistry for the detection of T. gondii. RESULTS: DNA of T. gondii and N. caninum was amplified in 11 (28.95%) 10 (26.32%) of samples analyzed, respectively. Coinfection was observed in three individuals. One animal returned a positive result in the immunohistochemistry for the detection of T. gondii. CONCLUSION: These findings reflect a concern for the conservation of these animals, as the pathogen-host interaction is unpredictable and infections by these protozoa can lead to animal mortality, which has a substantial impact on endangered species.

Molecular detection of trypanosomatids in neotropical primates in the state of Mato Grosso, Midwest, Brazil.

Trypanosomatids are uniflagellate protozoa belonging to the Trypanosomatidae family. The genera Trypanosoma and Leishmania are of paramount importance as they contain species that cause serious diseases, such as Chagas disease and Leishmaniasis, respectively. The objective of the present study was to identify trypanosomatids present in the whole blood of free-living and captive neotropical primates in Mato Grosso State, Midwest Brazil. Between 2017 and 2019, 38 blood samples were collected from seven different neotropical primate species in seven cities in the state. Through molecular techniques, including polymerase chain reaction (PCR) to amplify a fragment of the kinetoplast DNA (kDNA) and 18S ribosomal RNA (18S rRNA) gene, sequencing, and phylogenetic analysis, nine Leishmania spp. [seven L. infantum and two L. (Leishmania) amazonensis] and two Trypanosoma spp. (T. minasense and T. rangeli) were identified. This study contributes to understanding the occurrence and epidemiology of trypanosomatids in Mato Grosso State and the importance of neotropical primates as trypanosome hosts and possible infection sources for other animals and humans. Future identification of other blood pathogens in neotropical primates will assist in disease control and prevention strategies.

Multidrug-resistant mcr-1 gene-positive Klebsiella pneumoniae ST307 causing urinary tract infection in a cat.

RESUMO: The Klebsiella pneumoniae (K. pneumoniae) bacterium is responsible for many opportunistic infections such as sepsis, and a multidrug-resistant (MDR) clone sequence type (ST) 307 has recently begun to spread. The objective of this study was to report the first occurrence of this virulent genotype, which was found in the context of a urinary infection in a domestic feline in Brazil. The K. pneumoniae isolate was identified from the urine of a 6-month-old male crossbreed cat using 16S rRNA sequencing. It was then subjected to antimicrobial susceptibility testing, followed by multilocus sequence typing analysis, and PCR detection of virulence and resistance genes. The antimicrobial susceptibility profile demonstrated that the isolate was MDR and associated with the presence of the colistin resistance gene (mcr-1). Genotyping allowed us to classify the isolate as K. pneumoniae ST307 with the presence of wabG, uge, and entB genes. MDR K. pneumoniae is important in human and veterinary medicine because it causes many types of infections. Clonal propagation of virulent or MDR genotypes such as K. pneumoniae ST307 is a global concern. This report of ST307 isolation from a urine sample in a domestic feline is the first in Brazil.

Presença da mutação do gene BRCA1 em cadelas com tumores mamários malignos / Presence of BRCA1 gene mutation in bitches with malignant mammary tumors

Mammary tumors (MTs) in bitches are similar to breast cancers in women. Thus, they can be used as a model for human breast cancer and findings can be extrapolated for use in human medicine. BRCA1 is a tumor suppressor gene. When the gene has a mutation, it cannot repair damaged DNA, which causes genetic instability and tumorigenesis. Therefore, we aimed to study the frequency of single nucleotide polymorphisms (SNPs) in the BRCA1 gene that are associated with distinct histological types of malignant MT in bitches. The study population consisted of 91 bitches, including a control group of 6 animals with healthy mammary glands and 85 animals with MTs. All animals underwent a presurgery evaluation consisting of a questionnaire administered to the person responsible for the animal, a physical examination, collection of peripheral blood for hematological and serum biochemistry evaluations, an electrocardiogram, and a preanesthesia evaluation. In addition, distant metastasis was studied via chest radiography and abdominal ultrasound. After evaluations were complete, the animals that could undergo surgery were administered general anesthesia and underwent a mastectomy or mammary gland sample collection. Histopathological examination and molecular analysis were performed to identify mutations in the BRCA1 gene. Histopathological examinations found 10 different types of malignant tumors in 36 sick animals. Tumor samples plus samples from the 6 control animals were subjected to DNA extraction, polymerase chain reaction (PCR) analysis, and genetic sequencing. The tumor with the highest incidence (33.33%) was a complex carcinoma, followed by carcinoma in mixed tumor (13.88), tubular carcinoma (13.88) and carcinosarcoma (13.88). Molecular analysis revealed 3 different SNP points in 5 samples (4006G>A, 3619A>G, and 3761C>T). The allelic variant 4006G>A (1/36) resulted in the alteration of the amino acid valine by isoleucine (V1336 I). The mutation 3619A>G (2/36) inserted the amino acid alanine instead of threonine (T1207 A). The mutation 3761C>T (2/36) led to the alteration of the amino acid serine by phenylalanine (S1254 F), a mutation for which there are no published reports. The histological types that showed BRCA1 mutations were complex carcinoma (1/5), carcinoma in mixed tumor (1/5), papillary carcinoma (1/5) and tubular carcinoma (2/5). Software analysis identified the new SNP (nucleotide 3761) in BRCA1 and 2 point mutations in nucleotides 4006 and 3619 and responsible for genetic instability. The development of breast cancer is caused by many endogenous and exogenous factors. The results of our study show that these factors have a greater presence in female, mixed breed, uncastrated, and older dogs, confirming the data in the veterinary literature. In the present study, we found different histological types of malignant breast tumors with mutations in the BRCA1 gene, as other authors have reported. However, we also found the mutation 3761C>T, which, to the best of our knowledge, has not been reported in the literature. This shows the need for studies in veterinary medicine that assess mutations in the BRCA1 gene and the most common histological types. In conclusion, SNPs in the BRCA1 gene cause genetic instability, resulting in additional mutations that lead to the development of breast tumors. They are point mutations that affect transcription, resulting in truncated proteins. These proteins may have a loss of function, leading to carcinogenesis.(AU)

Vancomycin susceptibility profiles of Staphylococcus spp. isolates from domestic and wild animals / Perfil de suscetibilidade à Vancomicina de isolados de Staphylococcus spp. de animais domésticos e silvestres

ABSTRACT: Staphylococcus spp. are bacteria involved in human and animal infections. They are resistant to antimicrobials and have become a major public health concern. In recent years, there has been a significant increase in methicillin-resistant Staphylococcus strains and vancomycin is the drug of choice for the treatment of such isolates. However, the minimum inhibitory concentration (MIC) of vancomycin ​​necessary to combat this microorganism has been showing an increase. The aim of the present study was to determine the susceptibility profile of the Staphylococcus spp. of domestic and wild animals to vancomycin, using the microdilution in broth and E-test® techniques, as well as comparing the results of both tests. Of the 50 isolates tested, 47 (94 %) were sensitive to vancomycin in the microdilution and 43 (86 %) were sensitive to vancomycin in the E-test®. Seven (14 %) isolates had an intermediate result showing a risk to public health since the detection of these isolates may precede the occurrence of isolates resistant to vancomycin. In addition, the mecA gene was detected in 78 % of the tested samples. Six of the seven isolates with intermediate resistance to vancomycin were carriers of the mecA gene, showing that these isolates had a potential risk of becoming resistant. Thus, control measures must be taken to prevent the spread of these isolates with intermediate resistance and preserve the effectiveness of this antimicrobial for the treatment of infections caused by multiresistant Staphylococcus spp.

RESUMO: Staphylococcus spp. são bactérias envolvidas em infecções de humanos e animais, resistentes a antimicrobianos e tem se tornado uma grande preocupação em saúde pública. Nos últimos anos houve um aumento significativo de Staphylococcus resistentes à meticilina e a vancomicina é a droga de escolha para o tratamento desses isolados, porém vem apresentando elevação nos valores de Concentração Inibitória Mínima (CIM) necessários para combater este microrganismo. O objetivo do presente trabalho foi determinar o perfil de suscetibilidade à vancomicina para isolados de Staphylococcus spp. de animais domésticos e silvestres pelas técnicas de Microdiluição em caldo e E-test®, bem como comparar os resultados de ambos os testes. Dos 50 isolados testados 47 (94%) foram sensíveis à vancomicina na Microdiluição e 43 (86%) foram sensíveis à vancomicina no E-test®. Sete (14%) isolados tiveram resultado intermediário demonstrando um risco à saúde pública visto que a detecção destes isolados pode preceder a ocorrência de isolados resistentes à vancomicina. Ademais o gene mecA foi detectado em 78% das amostras testadas, sendo que dos sete isolados com resistência intermediária à vancomicina, seis eram portadores do gene mecA, evidenciando que esses isolados possuem potencial risco de se tornarem resistentes. Dessa forma medidas de controle devem ser tomadas para evitar a propagação destes isolados com resistência intermediária e preservar a eficácia deste antimicrobiano para o tratamento de infecções causadas por Staphylococcus multirresitentes.

Molecular survey and genetic diversity of piroplasmids in equids from Midwestern Brazil / Levantamento molecular e diversidade genética de piroplasmídeos em equídeos do Centro-Oeste do Brasil

Abstract We evaluated the distribution of piroplasmids in equids from the Mato Grosso state in Midwestern Brazil using molecular methods and the interspecific genetic diversity. For this, 1,624 blood samples of equids from 973 farms were examined by PCR, using primer pairs that amplify a fragment of the genes rap-1 and ema-1 of Babesia caballi and Theileria equi, respectively. For molecular characterization and phylogenetic studies, 13 and 60 sequences of the rap-1 and ema-1 genes, respectively, were used to build a dendogram using maximum parsimony. B. caballi and T. equi were detected in 4.11% and 28.16% of the farms, respectively, and molecular prevalence was 2.74% for B. caballi and 25.91% for T. equi. The location of the farms and animals raised in the Pantanal ecoregion influence the probability of equids testing positive for B. caballi and T. equi . Moreover, age and herd purpose were variables significantly associated with T . equi infection. The sequences of B. caballi presented 1.95% intraspecific variability, contrasting with 2.99% in T. equi. Dendrograms for both species demonstrated the presence of subgroups with high values of support of branches. However, it is not possible to associate these groups with geographic origin and/or ecoregion.

Resumo Foi avaliada a distribuição de piroplasmídeos em equídeos do Estado de Mato Grosso, no Centro-Oeste do Brasil, utilizando-se métodos moleculares e a diversidade genética interespecífica. Para isso, 1.624 amostras de sangue de equídeos de 973 fazendas foram examinadas pela PCR, usando pares de oligonucleotídeos que amplificam um fragmento dos genes rap-1and ema-1 de Babesia caballi e Theileria equi, respectivamente. Para caracterização molecular e estudos filogenéticos, foram utilizadas 13 e 60 sequências dos genes rap-1 e ema-1, respectivamente, para construção de um dendograma utilizando máxima parcimônia. B. caballi e T . equi foram detectados em 4,11% e 28,16% das fazendas, respectivamente, e a prevalência molecular foi de 2,74% para B. caballi e 25,91% para T. equi. A localização das fazendas e animais criados na ecorregião do Pantanal influenciam a probabilidade de equídeos serem positivos para B. caballi e T. equi. Além disso, idade e propósito do rebanho foram variáveis, significativamente, associadas à infecção por T. equi. As sequências de B . caballi apresentaram variabilidade intraespecífica de 1,95%, contrastando com 2,99% em T. equi. Dendrogramas para ambas as espécies demonstraram a presença de subgrupos com altos valores de sustentação dos ramos. No entanto, não é possível associar esses grupos com origem geográfica e/ou ecorregião.

Molecular survey and genetic diversity of piroplasmids in equids from Midwestern Brazil.

We evaluated the distribution of piroplasmids in equids from the Mato Grosso state in Midwestern Brazil using molecular methods and the interspecific genetic diversity. For this, 1,624 blood samples of equids from 973 farms were examined by PCR, using primer pairs that amplify a fragment of the genes rap-1 and ema-1 of Babesia caballi and Theileria equi, respectively. For molecular characterization and phylogenetic studies, 13 and 60 sequences of the rap-1 and ema-1 genes, respectively, were used to build a dendogram using maximum parsimony. B. caballi and T. equi were detected in 4.11% and 28.16% of the farms, respectively, and molecular prevalence was 2.74% for B. caballi and 25.91% for T. equi. The location of the farms and animals raised in the Pantanal ecoregion influence the probability of equids testing positive for B. caballi and T. equi . Moreover, age and herd purpose were variables significantly associated with T . equi infection. The sequences of B. caballi presented 1.95% intraspecific variability, contrasting with 2.99% in T. equi. Dendrograms for both species demonstrated the presence of subgroups with high values of support of branches. However, it is not possible to associate these groups with geographic origin and/or ecoregion.

Identification of Pasteurella multocida transcribed genes in porcine lungs through RNAseq.

Pasteurella multocida is one of the most important pathogen that causes pneumonia in swine. Although several virulence factors are known, the pathogenesis of this bacterium is not well-studied. Therefore, to study the pathogenesis of P. multocida infection in porcine lung, next-generation RNA sequencing was used to compare the transcriptomes of P. multocida grown in vivo and in vitro, respectively. After P. multocida infection a total of 704 genes were expressed in vitro, 1422 genes were expressed in vivo, and 237 genes were differentially expressed based on statistical analyses, padj of ≤0.1. Genes encoding ribosomal proteins or other products that function in the regulation of transcription and translation were downregulated, whereas genes whose products affected cellular processes (protein transport and RNA degradation) and metabolic pathways, such as those of amino acid metabolism and nucleotide metabolism, were upregulated in vitro compared with in vivo. This study shows that differentially expressed genes in P. multocida regulate pathways that operate during stress, iron capture, heat shock, and nitrogen regulation. However, extensive investigation of the pathogenic mechanism of P. multocida is still required.

Detection of noroviruses in free-ranging jaguars (Panthera onca) in the Pantanal, Mato Grosso, Brazil.

Nine free-ranging jaguars (Panthera onca) were captured, and rectal swabs were collected in the Pantanal of Cáceres, Mato Grosso, Brazil. Reverse transcription polymerase chain reaction specific for noroviruses was performed. Six jaguars (66.6%) tested positive for norovirus genotype GII.11.

Polymerase Chain Reaction and blood culture for diagnosis of canine sepsis / Reação em Cadeia da Polimerase e hemocultura para diagnóstico de sepse canina

ABSTRACT: Sepsis is characterized by the presence of organ dysfunction secondary to the dysregulated systemic inflammatory response associated with an infection, and has high mortality rates. Traditional diagnostic techniques based on non-microbiological isolation are time-consuming and may delay treatment. Thus, this study aimed to compare bacterial and fungal broad-range polymerase chain reaction (PCR) and blood culture for diagnosis of sepsis in dogs. Blood samples from 88 dogs with suspected sepsis were analyzed by blood culture, and PCR to detect bacterial and fungal DNA. On blood culture, 20 (22.7%) samples tested positive for bacterial isolates; however, none tested positive for fungi. Through PCR analysis, bacterial DNA was detected in 46 (52.3%) animals, whereas fungal DNA was present in one (1.1%) sample. Our results showed that PCR-based testing has important diagnostic value for canine blood infections because it has a shorter turnaround time and higher sensitivity than traditional blood culture.

RESUMO: Sepse se caracteriza pela presença de disfunção orgânica secundária à resposta inflamatória sistêmica desregulada, associada a uma infecção com elevadas taxas de mortalidade. As técnicas tradicionais baseadas no isolamento microbiológico são demoradas e podem atrasar o tratamento. O objetivo deste estudo foi comparar a Reação em Cadeia da Polimerase (PCR) bacteriana e fúngica e hemocultura em cães com sepse. Foram analisadas 88 amostras de sangue de cães com suspeita de sepse por meio de hemocultura e PCR para detectar DNA bacteriano e fúngico. Nas culturas sanguíneas, 20 (22,7%) amostras foram positivas para isolados bacterianos. No entanto, nenhuma amostra foi positiva para fungos. Através da análise por PCR, o DNA bacteriano foi detectado em 46 animais (52,3%), enquanto que o DNA fúngico estava presente em uma amostra (1,1%). Neste caso, a PCR apresenta importante valor diagnóstico em cães com infeções sanguíneas devido a sua rapidez e maior sensibilidade do que a isolamento por hemocultura.

Experimental infection in gerbils by Conidiobolus lamprauges.

Conidiobolomycosis is an emerging entomophthoramycosis caused by fungi Conidiobolus spp. Animal models are essential for the study of infectious disease in various areas such as pathogenesis, diagnostic methods, treatment and prevention. There is not currently an animal model for conidiobolomycosis. The aim of this study was to create an experimental infection protocol for Conidiobolus lamprauges in gerbils (Meriones unguiculatus). The study animals were randomly divided into four groups of four animals: immunosuppressed with cyclophosphamide (CPA) and infected with C. lamprauges (G1), immunocompetent and infected with C. lamprauges (G2), immunosuppressed with CPA (G3), and an immunocompetent control group (G4). Clinical signs were observed only in G1 animals, where the mortality rate reached 75% by day 7 after infection (AI) with a median survival of 2 days. C. lamprauges was detected only in G1, both by PCR and by isolation. Necropsies of the G1 animals showed lesions in the nasal cavity and lung tissue. These lesions were characterized by polymorphonuclear infiltrate cells and by the presence of hyphal structures under silver staining. This animal model will be useful for further investigation of diseases caused by C. lamprauges, particularly of those associated with immunosuppression factors in naturally occurring animal infections.

Molecular characterization of Pasteurella multocida isolates from swine lungs by Randomly Amplified Polymorphic DNA / Caracterização molecular de isolados de Pasteurella multocida de pulmões de suínos através da técnica Randonly Amplified Polymorphic DNA

ABSTRACT: Swine respiratory diseases such as atrophic rhinitis and bronchopneumonia caused by Pasteurella (P.) multocida cause important economic losses to the modern swine industry. The purpose of this study was to characterize P. multocida strains isolated from swine lungs by RAPD (Randomly Amplified Polymorphic DNA) to demonstrate their genetic diversity. Ninety-four samples of fragments from lungs with pneumonia and sixty one samples without pneumonia were collected in slaughterhouses in Mato Grosso during the period from December 2009 to March 2010. Clinical cases in 2012 and 2013 were also included in this study. Among the lung fragments with macroscopic lesions, without macroscopic lesions and clinical samples, 40.42%, 4.49% and 100% were positive for P. multocida, respectively. Bacterial identification culturing was confirmed by PCR (polymerase chain reaction) by means of the amplification of the gene kmt1. RAPD technique was performed for 46 isolates, and in every isolate, a total of 7 to 11 amplification bands were detected, composed of 8 clusters based on genetic similarity. Thus, treatment, control and preventive measures should consider the genetic diversity of P. multocida populations in swine herds in order to improve the development of new protocols to produce antimicrobials and vaccines.

RESUMO: As doenças respiratórias suínas como a rinite atrófica e broncopneumonia, associada a Pasteurella (P.) multocida causam importantes perdas econômicas na suinocultura moderna. O objetivo deste trabalho foi caracterizar isolados de P. multocida de pulmão suíno através do Randomly Amplified Polymorphic DNA (RAPD) para demonstrar a diversidade genética. Noventa e quatro amostras de fragmentos de pulmões com lesões de pneumonia e sessenta e uma amostras sem lesão foram coletadas em frigoríficos no Estado do Mato Grosso, durante o período de dezembro de 2009 a março de 2010. Amostra de casos clínicos ocorridos em 2012 e 2013 também foram inlcuídos. Amostras de pulmões com lesões macroscópicas, sem lesões macroscópicas e amostras clínicas apresentaram presença de 40,42%, 4,49% e 100% de isolamento para P. multocida, respectivamente. Os isolados foram todos confirmados através da PCR (Polymerase Chain Reaction) pela amplificação do gene kmt1. A técnica de RAPD foi realizada em 46 amostras e em cada isolado foi detectado 7 a 11 bandas, que foram agrupadas em 8 grupos baseados em suas similaridades genéticas. Dessa forma, tratamento, controle e medidas preventivas deveriam considerar a diversidade genética da população de P. multocida em rebanhos suínos para melhorar o desenvolvimento de novos protocolos para produção de antimicrobianos e vacinas.