Endocarditis de la válvula aórtica causada por Brucella melitensis / Aortic valve endocarditis caused by Brucella melitensis

La endocarditis bacteriana secundaria a la infección por Brucella spp., en este caso B. melitensis, como complicación de la brucelosis humana tiene una incidencia baja y, aunque es la presentación clínica con la que se asocia más frecuentemente la mortalidad, no todos los casos son letales, si son tratados oportunamente. Se describe el caso clínico de una endocarditis bacteriana por B. melitensis, diagnosticada en un adulto por el aislamiento del microorganismo en el hemocultivo. Paciente del sexo masculino, de 40 años, con antecedentes de realizar partos en el ganado bovino y consumir leche no pasteurizada. Acudió al médico por presentar durante siete días de evolución de las siguientes manifestaciones clínicas: fiebre, mialgias, artralgias, tos seca y pérdida de peso (15 kg). El hemograma informa: leucopenia, trombocitopenia y anemia; mientras que en un ecocardiograma transesofágico se observó vegetación en la válvula aórtica con una disminución de la función sistólica y en el hemocultivo se aisló B. melitensis. Debido a estos antecedentes, se inició el tratamiento antibacteriano con rifampicina, doxiciclina y gentamicina. El paciente se recuperó y tuvo una evolución clínica satisfactoria. La brucelosis es una enfermedad infrecuente. Debe considerarse en toda persona con fiebre de foco desconocido que resida en zonas endémicas o esté expuesto al cuidado de animales de granja. En esta enfermedad se impone un diagnóstico y tratamiento preciso, por ser una complicación con alta letalidad.

Bacterial endocarditis, secondary to Brucella spp. infection, in this case by B. melitensis, as a complication of human brucellosis has a low incidence. Although it is the clinical presentation most frequently associated with mortality, not all cases are lethal if timely treatment is provided. We describe a clinical case of bacterial endocarditis due to B. melitensis in a 40-year-old male patient with a history of conducting cattle deliveries and consuming unpasteurized milk, diagnosed after isolating the microorganism in blood culture. He presented with the following clinical manifestations after seven days of evolution: fever, myalgias, arthralgias, dry cough and weight loss (15 kg). The hemogram revealed leukopenia, thrombocytopenia, and anemia; while a transesophageal echocardiogram showed vegetation on the aortic valve with decreased systolic function, and B. melitensis was isolated in a blood culture. Considering this medical history, antibacterial treatment was initiated with rifampicin, doxycycline and gentamicin. The patient recovered and had satisfactory clinical evolution. Brucellosis is a rare disease. It should be considered in any person with a fever of unknown origin who lives in endemic areas or is exposed to the care of farm animals. Endocarditis is a highly lethal complication of human brucellosis; therefore, it requires a precise diagnosis and treatment.

Brucella meningoencephalitis in children with status epilepticus A case report and literature review / 中国热带医学

@#Abstract: Objective　To investigate the clinical characteristics and incidence of Brucella encephalitis and meningitis in children. Methods We report the clinical data of a child with Brucella melitensis meningitis in children, and summarize the incidence, diagnosis methods and treatment of Brucella encephalitis or meningitis in children, taking into account the relevant domestic and foreign literature from January 2014 to December 2020. Results　A 4-year-old girl was admitted to the hospital with status epilepticus on March 15, 2021 because of interrupted right limb numbness for 16 hours and convulsions for 2 hours. She had 2 non-febrile convulsions three months before admission and was diagnosed with epilepsy. This incident was acute, accompanied by low fever, with epilepsy as the main manifestation. Cerebrospinal fluid test suggested central nervous system infection, but the nature of infection could not be determined by routine and biochemistry of cerebrospinal fluid.The cerebrospinal fluid next generation sequencing confirmed that the pathogen of the infection was B. melitensis, which was further verified by the peripheral blood antibody test. After effective antibiotics combined with a full course of treatment, the patient recovered after six months of treatment. A total of 60 articles were retrieved in the database, including 29 in Chinese. During this period, a total of 7 cases of brucellosis in children with nervous system involvement were reported, one of which was a case report, and the other 6 cases were mentioned in the comprehensive analysis of children with brucellosis. Conclusions　Brucella encephalitis or meningitis in children has a low incidence and various clinical features, which are easy to be misdiagnosed or missed.

Primer caso confirmado de brucelosis humana por Brucella melitensis, una zoonosis presente en Colombia / First confirmed case of human brucellosis by Brucella melitensis, a zoonosis present in Colombia

Resumen La brucelosis, principal zoonosis a nivel mundial tiene alta prevalencia en varios países de Latinoamérica. Se asocia con la exposición a ganado infectado por distintas especies del género Brucella. B. melitensis la más virulenta para el humano, causa con frecuencia complicaciones de predominio osteoarticular. En Colombia se cree que la infección por B. melitensis es una entidad ausente, a pesar de su plausibilidad biológica en nuestro contexto; sin embargo, son escasos los estudios sobre su ocurrencia y mínimo el índice de sospecha de la enfermedad, por lo cual creemos está subdiagnosticada. Presentamos el primer caso confirmado de brucelosis por B. melitensis en Colombia en una joven embarazada, con diagnóstico incidental, en quien el análisis retrospectivo de su cuadro clínico alertó sobre puntos clave que pueden impactar en el diagnóstico y tratamiento oportuno de la enfermedad. Se plantean preguntas de prevalencia real de esta entidad en Colombia.

Summary Brucellosis, the principal zoonoses globally is highly prevalent in different countries of Latin America. It is associated with the exposition of livestock infected with different Brucella species, being B. melitensis the most virulent for humans, and frequently causing osteoarticular complications. In Colombia it is believed that B. melitensis infection is an absent entity, despite its biological plausibility in our context; however, there are few studies on its occurrence and a minimum index of suspicion of the disease, which is why we believe it is underdiagnosed. We present the first confirmed case of brucellosis by B. melitensis in Colombia diagnosed in a young pregnant patient, with an incidental diagnosis, in whom a retrospective analysis of her clinical outcome warned of key points that may impact on the diagnosis and timely treatment of the disease. We present several questions surrounding the real prevalence of this entity in Colombia.

Knee and the farm animals: An unusual presentation of Brucella melitensis masquerading as tuberculosis

In many developed countries, brucellosis has been successfully eradicated. However, brucellosis, with its myriad presentations, continues to be a clinical and diagnostic challenge in primarily agrarian countries such as India. We present a case of a rare manifestation of brucellosis i.e., septic arthritis of the knee joint associated with a lytic lesion of the proximal tibia. The patient belonged to a Brucella endemic country, and clinical features were of chronic reactive knee arthritis with synovial hypertrophy and effusion. Advanced diagnostic methods played a pivotal role in excluding the diagnosis of tuberculosis, and thus unnecessary administration of antitubercular therapy and initiating focused narrowed anti-Brucella management, achieving the goal of antimicrobial stewardship also.

Cellulitis in human brucellosis: An atypical presentation

@#Introduction: Brucellosis is a zoonotic disease with variable clinical manifestations and atypical presentation in humans. Human brucellosis cases are not seen often in Malaysia. Case Report: This is a case report of 19 years old gentleman who presented with fever, lower limb redness, pain and swelling. He was initially treated as cellulitis. However, based on the recovery of Brucella melitensis from his blood culture, he was later diagnosed to have brucellosis. He had a history of consumption of fresh goat’s milk and uncooked meat which could have been the possible modes of transmission. Brucella serology IgM and IgG were both positive, and anti-Brucella immunocapture agglutination test (BrucellaCapt) was also positive with a titer of 1:2560. He was treated with six weeks of oral doxycycline 100 mg twice daily and oral rifampin 450 mg twice daily. Discussion: This is a case of human brucellosis with atypical cutaneous involvement.

An Imported Case of Brucella melitensis Infection in South Korea / 감염과화학요법

Brucellosis is a zoonotic infection that is usually transmitted from cattle to humans through ingestion of animal milk, direct contact with animal parts, or inhalation of aerosolized particles. In Korea, brucellosis seem to be transmitted through close contact with blood, fetus, urine, and placenta of domestic cow that has been infected by Brucella abortus, or inhalation of B. arbortus while examining or slaughtering cow. Brucella melitensis infection is rare in Korea and there have been no reported cases of B. melitensis originating from other countries until now. This report details a case of complicated brucellosis with infective spondylitis in a 48-year-old male construction worker recently returned from Iraq. Infection with B. melitensis was confirmed using 16s rRNA sequencing and omp31 gene analysis. The patient was successfully treated using a combination of rifampin, doxycycline, and streptomycin, in accordance with WHO guidelines. This is the first reported case of complicated brucellosis with infective spondylitis in Korea caused by B. melitensis originating from Iraq.

An Imported Case of Brucella melitensis Infection in South Korea / 감염과화학요법

Brucellosis is a zoonotic infection that is usually transmitted from cattle to humans through ingestion of animal milk, direct contact with animal parts, or inhalation of aerosolized particles. In Korea, brucellosis seem to be transmitted through close contact with blood, fetus, urine, and placenta of domestic cow that has been infected by Brucella abortus, or inhalation of B. arbortus while examining or slaughtering cow. Brucella melitensis infection is rare in Korea and there have been no reported cases of B. melitensis originating from other countries until now. This report details a case of complicated brucellosis with infective spondylitis in a 48-year-old male construction worker recently returned from Iraq. Infection with B. melitensis was confirmed using 16s rRNA sequencing and omp31 gene analysis. The patient was successfully treated using a combination of rifampin, doxycycline, and streptomycin, in accordance with WHO guidelines. This is the first reported case of complicated brucellosis with infective spondylitis in Korea caused by B. melitensis originating from Iraq.

Etiological characteristics of the first human derived Brucella melitensis type 3 in Gansu Province / 中华地方病学杂志

Objective To analyze the etiological characteristics of human Brucella strains isolated, and to improve the precision in control and prevention of brucellosis. Methods In 2016, blood samples were collected from patients in Jingyuan County Gansu Province, and tested via the Rose-Bengal Plate Agglutination Test (RBPT) and the tube agglutination test methods,and serological positive blood samples were inoculated to bidirectional blood culture bottle for culturing, and further identified by traditional biological classification method and the Brucella abortus, Brucella melitensis, Brucella ovis, and Brucella suis species-specific PCR (AMOS-PCR). Multiple-locus variable number tandem repeat sequence analysis (MLVA) -16 was used to detect molecular typing and do cluster analysis. Results The isolated strain was identified by the traditional biological classification method, bacteria could grow in thionine and reddened dye, A and M factors agglutination tests were positive, Bk2phage treatment of bacterial strain cracking, but Tb, Wb phages were not cracked. AMOS-PCR amplification result showed a 731 bp band, which was a strain of Brucella melitensis. The results of MLVA-16 showed that there was a difference in the number of repeats on some Variaable Number of Tandem Repeat(VNTR)sites of the isolated strain. Clustering analysis showed that, the isolated strain was clusted into the same clade with the clustering of Brucella melitensis type 3 from GS-201605 in Gansu. And the clustering was similar compared with that of Zhejiang, Guangdong, Fujian and Yunnan. Conclusion Human brucellosis is a inputting transmission in Gansu Province, there is a genetic variation of genotype 3 sheep Brucella between Gansu Province and other domestic provinces.

HOOF genotyping characteristics of Brucella melitensis strains isolated in Ulanqab of Inner Mongolia Autonomous Region / 中华流行病学杂志

Objective To investigate the HOOF genotyping characteristics of 83 Brucella (B.)melitensis strains isolated in Ulanqab of Inner Mongolia Autonomous Region from 2012 to 2015.Methods A total of 83 B.melitensis strains were detected by convention identification and AMOS-PCR,then HOOF protocol with eight VNTR locus were used for the genotyping of the strains,and the allelic diversity of each VNTR locus and the discriminatory power of VNTR typing of HOOF were assessed by Hunter-Gaston Discriminatory index.BioNumerics 5.0 was used for phylogenetic analysis and constructing dendrogram.Results All of the isolates were identified as B.melitensis strains by two identification methods.The complete eight VNTR locus had higher polymophism and diversity index was 0.998;and diversity index of six locus (1,2 and 4-7) were ≥0.678,discriminatory power of HOOF was mainly from this six higher diversity index locus.The 83 B.melitensis strains were classified into eight clusters and 76 genotypes,6 shared genotypes included 13 isolates,indicating that these brucellosis cases had epidemiological link,the other 70 strains had distinct genotypes,indicating that these cases had no epidemiological link.Conclusions The epidemic of human brucellosis in Ulanqab was characterized by local and sporadic outbreaks.Cross infection was related with the transfer of the sources of infection.

HOOF genotyping characteristics of Brucella melitensis strains isolated in Ulanqab of Inner Mongolia Autonomous Region / 中华流行病学杂志

Objective To investigate the HOOF genotyping characteristics of 83 Brucella (B.)melitensis strains isolated in Ulanqab of Inner Mongolia Autonomous Region from 2012 to 2015.Methods A total of 83 B.melitensis strains were detected by convention identification and AMOS-PCR,then HOOF protocol with eight VNTR locus were used for the genotyping of the strains,and the allelic diversity of each VNTR locus and the discriminatory power of VNTR typing of HOOF were assessed by Hunter-Gaston Discriminatory index.BioNumerics 5.0 was used for phylogenetic analysis and constructing dendrogram.Results All of the isolates were identified as B.melitensis strains by two identification methods.The complete eight VNTR locus had higher polymophism and diversity index was 0.998;and diversity index of six locus (1,2 and 4-7) were ≥0.678,discriminatory power of HOOF was mainly from this six higher diversity index locus.The 83 B.melitensis strains were classified into eight clusters and 76 genotypes,6 shared genotypes included 13 isolates,indicating that these brucellosis cases had epidemiological link,the other 70 strains had distinct genotypes,indicating that these cases had no epidemiological link.Conclusions The epidemic of human brucellosis in Ulanqab was characterized by local and sporadic outbreaks.Cross infection was related with the transfer of the sources of infection.

Identification of Brucella strain isolated from sheep blood in Jingyuan County Gansu Province / 中华地方病学杂志

Objective To identify the Brucella strains isolated from sheep blood in Jingyuan County Gansu Province,and to provide scientific basis for Brucellosis control and prevention.Methods In 2016,blood samples from suspected cases of sheep were collected in the home of Brucellosis patient of Jingyuan County,and cultured with vaccination double blood bottles via the enrichment method,and the Brucella strains isolated from sheep were identified by traditional bio-typing,genus specific Brucella surface protein 31 PCR (BSCP31-PCR) and Brucella abortus,Brucella melitensis,Brucella ovis,Brucella suis species-specific PCR (AMOS-PCR),respectively.Results The isolated strain was identified using the traditional biological classification method,bacteria could grow in thionine and fuchsin dyes,A and M factors serum agglutination tests were positive,Bk2 phage lysis test was positive,but Tb and Wb phage lysis tests were negative;and the results of BSCP31-PCR of tested strain was 223 bp band same to Brucella;the results of AMOS-PCR was 731 bp band same to Brucella melitensis.Conclusion Conventional bio-typing test assisted with molecular techniques has confirmed that the isolated Brucella strain from sheep blood is Brucella melitensis type 3 in Jingyuan County Gansu Province.

A Novel PCR Assay for Detecting Brucella abortus and Brucella melitensis

OBJECTIVES: Brucellosis is a major zoonotic disease that poses a significant public health threat worldwide. The classical bacteriological detection process used to identify Brucella spp. is difficult and time-consuming. This study aimed to develop a novel molecular assay for detecting brucellosis. METHODS: All complete sequences of chromosome 1 with 2.1-Mbp lengths were compared among all available Brucella sequences. A unique repeat sequence (URS) locus on chromosome 1 could differentiate Brucella abortus from Brucella melitensis. A primer set was designed to flank the unique locus. A total of 136 lymph nodes and blood samples were evaluated and classified by the URS-polymerase chain reaction (PCR) method in 2013–2014. RESULTS: Biochemical tests and bacteriophage typing as the golden standard indicated that all Brucella spp. isolates were B. melitensis biovar 1 and B. abortus biovar 3. The PCR results were the same as the bacteriological method for detecting Brucella spp. The sensitivity and specificity of the URS-PCR method make it suitable for detecting B. abortus and B. melitensis. CONCLUSION: Quick detection of B. abortus and B. melitensis can provide the most effective strategies for control of these bacteria. The advantage of this method over other presented methods is that both B. abortus and B. melitensis are detectable in a single test tube. Furthermore, this method covered 100% of all B. melitensis and B. abortus biotypes. The development of this URS-PCR method is the first step toward the development of a novel kit for the molecular identification of B. abortus and B. melitensis.

Antimicrobial susceptibility testing of Brucella melitensis isolated from patients with acute brucellosis in a centre of Iran.

Structured to Purpose: Human brucellosis is one of the most common zoonotic infections worldwide, which remains one of the major problems for public health. Despite the World Health Organization’s recommendation for human brucellosis treatment, sporadic cases of relapse have been reported. The aim of this study was to assess the susceptibility of Brucella isolates to common antibiotics that are prescribed by the physician for the treatment of brucellosis and also to determine the minimum inhibitory concentration 50% (MIC50) and MIC90 for these antibiotics. Materials and Methods: Forty‑eight Brucella strains were collected from patients with acute brucellosis. Species identification was made based on the conventional methods. MIC of rifampin, doxycycline, ciprofloxacin, trimethoprim‑ sulfamethoxazole, streptomycin, azithromycin and ceftriaxone was determined by E‑test. Results: All the 48 Brucella isolates (47 blood samples and one synovial fluid) were identified as Brucella melitensis. No antimicrobial‑resistant strains were recognised. Trimethoprim‑sulfamethoxazole had the lowest MIC50 (0.016 µg/ml) and MIC90 (0.064 µg/ml), whereas MIC50 and MIC90 of streptomycin and azithromycin had the highest level at 0.625, 1.5 μg/ml and 0.25, 1 μg/ml, respectively. All the isolates were susceptible to rifampin, and only one of the isolates had a reduced sensitivity to rifampin (1 µg/ml). Conclusions: Although all the Brucella isolates were susceptible, antimicrobial susceptibility test should be recommended in patients with recurrent brucellosis or life‑threatening organ involvement.

Epidemiología de la brucelosis caprina y ovina en la provincia de Formosa, Argentina / Epidemiology of caprine and ovine brucellosis in Formosa province, Argentina

Se realizó un estudio epidemiológico de brucelosis en 516 majadas caprinas o mixtas (caprinos/ovinos) de las 3 regiones agroecológicas de la provincia de Formosa, Argentina. Mediante las pruebas de aglutinación en placa con antígeno tamponado y de fijación del complemento en suero se estudiaron un total de 25.401 caprinos y 2.453 ovinos. Además, se realizaron cultivos bacteriológicos y PCR en muestras de leche de cabras de 3 majadas con brucelosis y abortos recientes. Se detectó brucelosis en 4 de los 9 departamentos de la provincia, la prevalencia global fue del 2 % y la intrapredial varió entre el 1 y el 40%. La proporción de majadas positivas fue del 3,6, el 12 y el 36 % para las regiones este, centro y oeste, respectivamente. Se aisló Brucella melitensis bv. 1 de cabras por primera vez en la provincia. La PCR amplificó fragmentos esperados de 827 pb correspondiente al gen omp2ab (Brucella spp.) y de 731 pb correspondiente al inserto IS711 (B. melitensis). La detección de anticuerpos en ovinos que cohabitan con caprinos sugiere que las infecciones habrían sido causadas por B. melitensis, lo que constituye un riesgo adicional para la salud pública. Los programas de control y erradicación de la brucelosis deberían considerar las majadas mixtas como una sola unidad epidemiológica. Los resultados indican que la brucelosis por B. melitensis bv. 1 es altamente endémica en las regiones centro y oeste de la provincia de Formosa.

An epidemiological study of brucellosis was carried out in 516 goats and mixed flocks (goat/sheep) from the three agro-ecological regions of Formosa province, Argentina. Serum samples from a total of 25401 goats and 2453 sheeps were analyzed using buffered plate agglutination test (BPAT) and complement fixation test (CFT). Bacteriological and PCR analyses on milk samples from goats in three flocks with a history of brucellosis and recent abortions were also performed. Brucellosis was detected in four of the nine departments of the province with an overall prevalence of 2 % and an intra-flock prevalence ranging between 1 % and 40 %. The proportion of infected flocks was 3.6 %, 12 % and 36 % for the eastern, central and western regions, respectively. Brucella melitensis bv. 1 was isolated efrom goats for the first time in the province. The expected fragments of 827 bp from the omp2ab gene (Brucella spp.) and 731 bp from the insert IS711 (B. melitensis) were amplified by PCR. Detection of antibodies by BPAT and FCT in sheep cohabiting with goats suggests that infections could have been caused by B. melitensis, posing an additional risk to public health. Control and eradication programs for brucellosis should consider mixed flocks as a single epidemiological unit. The results indicate that brucellosis by B. melitensis bv1 is highly endemic in the central and western regions of Formosa province.

Isolation & characterization of Brucella melitensis isolated from patients suspected for human brucellosis in India.

Background & objectives: Brucellosis is endemic in the southern part of India. A combination of biochemical, serological and molecular methods is required for identification and biotyping of Brucella. The present study describes the isolation and biochemical, molecular characterization of Brucella melitensis from patients suspected for human brucellosis. Methods: The blood samples were collected from febrile patients suspected to have brucellosis. A total of 18 isolates were obtained from 102 blood samples subjected to culture. The characterization of these 18 isolates was done by growth on Brucella specific medium, biochemical reactions, CO2 requirement, H2S production, agglutination with A and M mono-specific antiserum, dye sensitivity to basic fuchsin and thionin. Further, molecular characterization of the isolates was done by amplification of B. melitensis species specific IS711 repetitive DNA fragment and 16S (rRNA) sequence analysis. PCR-restriction fragment length polymorphism (RFLP) analysis of omp2 locus and IS711 gene was also done for molecular characterization. Results: All 102 suspected samples were subjected to bacteria isolation and of these, 18 isolates could be recovered on blood culture. The biochemical, PCR and PCR-RFLP and 16s rRNA sequencing revealed that all isolates were of B. melitensis and matched exactly with reference strain B. melitensis 16M. Interpretation & conclusions: The present study showed an overall isolation rate of 17.64 per cent for B. melitensis. There is a need to establish facilities for isolation and characterization of Brucella species for effective clinical management of the disease among patients as well as surveillance and control of infection in domestic animals. Further studies are needed from different geographical areas of the country with different level of endemicity to plan and execute control strategies against human brucellosis.

Clinical analysis of 122 acute brucellosis patients' blood culture / 中华地方病学杂志

Objective By studying the acute brucellosis patients' blood culture and the bacteria strains,we tried to confirm the bacteria strains,and to further explore the symptoms and the results of the treatment.Methods Totally 122 acute brucellosis patients were selected,who were in hospital in Heilongjiang Provincial Nongken General Hospital from 2012 to 2013.The patients aged 6-73 years old,whose average age was 36.5(including 83 males and 39 females).All of the subjects were detected in the aspects of blood culture and brucellosis serology,all of whom were treated with aminoglycoside,4-quinolones and cephalosporins.Results All the subjects were Brucella melitensis biovar,of which 104 were Brucella melitensis biovar 3,18 were Brucella melitensis biovar 1.All of them had positive results in rose bengal plate agglutination test (RBPT).In serum tube agglutination test (SAT),the valence of Brucella melitensis biovar 1 and 3 were uniformly distributed,Brucella melitensis biovar 1 was distributed mainly in 1∶800 valence zone,Brucella melitensis biovar 3 was distributed mainly in 1∶400 valence zone.The distribution trends in Coombs test and complement fixation test (CFT) were similar.In Coombs they were distributed mainly in 1∶800 valence zone,and in CFT were distributed mainly in 1∶40 zone.All of the subjects had typical symptoms of brucellosis,and had various kinds of complications (spondylitis,toxipathic hepatitis,et al).Totally 112 of them were recovered,and 10 were improved.Conclusion The human brucellosis in Heilongjiang Province is caused by Brucella melitensis biovar 1 and 3,with severe symptoms and various kinds of complications,earlier diagnose and treatment will have a better effect.

Isolation of Brucella melitensis from a human case of chronic additive polyarthritis.

Brucellar arthritis remains under diagnosed owing to non‑specific clinical manifestations. Here, we report isolation of Brucella melitensis from synovial fluid of 5th metatarsophalangeal joint of a 39‑year‑old lady having unusually chronic asymmetric, additive, peripheral polyarthritis. This isolation was confirmed by Bruce‑Ladder polymerase chain reaction (PCR). The patient had a history of contact with an aborted goat. Rose Bengal Plate Agglutination Test (RBPT) and Standard Tube Agglutination Test (SAT) were positive for Brucella‑specific antibodies both for patient and in contact with sheep and goats. The patient was treated with doxycycline and rifampicin for 16 weeks and was recovered fully.

Identification of Brucella melitensis isolates originating from Mongolia and diagnostic real-time PCR evaluation using a specific SNP / 대한수의학회지

A real-time PCR assay using hybridization probe (HybProbe) has been developed to detect Brucella (B.) melitensis strains. The primer and HybProbe sets were designed based on the gap gene of chromosome I with a specific single nucleotide polymorphism of B. melitensis. Specificity of the assay was confirmed by comparison to reference Brucella species and other related strains. In the melting curve analysis, B. melitensis generated a peak at 67degrees C unlike those for other Brucella species observed at 61degrees C. Sensitivity of the assay for B. melitensis ranged from 20 ng to 200 fg of genomic DNA. The ability to identify 94 Mongolian B. melitensis isolates using the real-time PCR assay was identical to that of classical biotyping methods and differential multiplex PCR. These data showed that this new molecular technique is a simple and quick method for detecting B. melitensis, which will be important for the control and prevention of brucellosis.

Identification of novel transcripts and sRNA of Brucella melitensis by RNA-Seq / 中国人兽共患病学报

To identify novel transcripts and sRNA in genome of B .melitensis by transcriptome sequencing ,total RNA were extracted from B .melitensis culture and rRNA were removed .After the addition of adaptor ,RNA was reversely transcribed into cDNA ,which were then subjected to PCR amplification and sequencing .The generated reads were mapped to genome se‐quence of B .melitensis strain 16M .With the mapping results ,novel transcripts and sRNA were identified by bioinformatics methods .Sequencing results analysis showed that genome sequence was covered with the reads with good quality .A total of 773 genes were extended in their 5′and/or 3′ends of their original locations .Sixteen novel transcripts and 241 sRNAs candi‐dates were identified .RT‐PCR showed that some of the sRNAs were differentially expressed under stress conditions .In B . melitensis genome ,there is novel transcript which is not predicted .The sRNA does exist in B .melitensis and were expressed under different conditions .