RESUMEN
INTRODUCTION: Aminoglycosides are vital antibiotics for treating Brucella infections, because they interfere with bacterial protein production and are often combined with other antibiotics. They are cost-effective, have fewer side effects, and can penetrate biofilms. The prevalence of brucellosis has increased in recent years, increasing the need for effective treatments. In addition, the emergence of multidrug-resistant Brucella strains has highlighted the need for an updated and comprehensive understanding of aminoglycoside resistance. This systematic review aimed to provide a comprehensive overview of the global prevalence of aminoglycoside resistance in B. melitensis and B. abortus. METHODS: A systematic search of online databases was conducted and eligible studies met certain criteria and were published in English. Quality assessment was performed using the JBI Checklist. A random-effects model was fitted to the data, and meta-regression, subgroup, and outlier/influential analyses were performed. The analysis was performed using R and the metafor package. RESULTS: The results of this systematic review and meta-analysis suggested that the average prevalence rates of streptomycin, gentamicin, and amikacin resistance were 0.027 (95% confidence interval [CI], 0.015-0.049), 0.023 (95% CI, 0.017-0.032), and 0.008 (95% CI, 0.002-0.039), respectively. The prevalence of streptomycin resistance was higher in the unidentified Brucella group than in the B. abortus and B. melitensis groups (0.234, 0.046, and 0.017, respectively; p < 0.02). The prevalence of gentamicin resistance increased over time (r = 0.064; 95% CI, 0.018 to 0.111; p = 0.007). The prevalence of resistance did not correlate with the quality score for any antibiotic. Funnel plots showed a potential asymmetry for streptomycin and gentamicin. These results suggest a low prevalence of antibiotic resistance in the studied populations. CONCLUSION: The prevalence of aminoglycoside resistance in B. melitensis and B. abortus was low. However, gentamicin resistance has increased in recent years. This review provides a comprehensive and updated understanding of aminoglycoside resistance in B. melitensis and B. abortus.
Asunto(s)
Aminoglicósidos , Antibacterianos , Brucella abortus , Brucella melitensis , Brucelosis , Aminoglicósidos/farmacología , Brucella abortus/efectos de los fármacos , Brucella abortus/genética , Brucella abortus/aislamiento & purificación , Antibacterianos/farmacología , Brucelosis/microbiología , Brucelosis/epidemiología , Brucella melitensis/efectos de los fármacos , Brucella melitensis/aislamiento & purificación , Brucella melitensis/genética , Humanos , Prevalencia , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana , AnimalesRESUMEN
Brucellosis, caused by Brucella bacteria, is a common zoonotic infectious disease with various clinical manifestations in humans and animals. The disease is endemic in human and ruminant populations in Iran, with a particular prevalence in areas where humans have close interactions with livestock. Since domestic animals serve as the primary reservoir for brucellosis, this study aimed to identify the presence of Brucella spp. among aborted small ruminants in southeast Iran. Between 2021 and 2022, aborted fetuses of small ruminants (46 sheep and 4 goats) were collected from Zarand County in the Kerman province. Swab samples from the abomasum contents of these fetuses were obtained and subjected to DNA extraction. The samples were then tested for Brucella spp. detection using the polymerase chain reaction (PCR) method. Out of the 50 aborted fetuses examined, Brucella spp. was detected in 15 (30%) specimens, comprising 13 (28%) sheep and 2 (50%) goats. Species typing revealed the presence of Brucella ovis (6 sheep and 1 goat), Brucella melitensis (6 sheep), and Brucella abortus (1 sheep) among the positive specimens. This cross-sectional study highlights the high prevalence of various Brucella species in samples from small ruminant abortions in southeast Iran. Additionally, the identified Brucella species were not limited to their primary host livestock. These indicated potential cross-species transmission among small ruminants.
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Brucella melitensis , Brucelosis , Enfermedades de las Cabras , Enfermedades de las Ovejas , Humanos , Embarazo , Femenino , Animales , Ovinos , Irán/epidemiología , Estudios Transversales , Rumiantes , Brucelosis/epidemiología , Brucelosis/veterinaria , Brucelosis/diagnóstico , Brucella melitensis/genética , Cabras/microbiología , Ganado , Enfermedades de las Ovejas/microbiología , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/microbiologíaRESUMEN
Brucellosis remains one of the most worldwide distributed zoonosis inflicting serious economical and human health problems in many areas of the world. The disease is caused by different species of the genus Brucella that have different tropisms towards different mammals being the most relevant for human health Brucella abortus, Brucella melitensis and Brucella suis that infect cows, goats/sheep, and swine respectively. For B. melitensis, considered the species with more zoonotic potential and highly aggressive for animals, only one vaccine is available to date in the market: Rev 1. This attenuated strain has the disadvantage that is has a very high residual virulence for animals and humans and, for this reason, it is applied by ocular instillation which is technically challenging in many productive settings. For this reason, the search for new vaccines for caprine and ovine brucellosis is an active topic of research. We describe here the construction of a novel highly attenuated vaccine strain (Bm Delta-pgm) that confers excellent levels of protection against B. melitensis in the mouse model of infection. This strain is a clean deletion of the phosphoglucomutase (pgm) gene that codes for a protein that catalyzes the conversion of glucose-6-P to glucose-1-P, which is used as a precursor for the biosynthesis of many polysaccharides, including the O-antigen of the lipopolysaccharide and cyclic beta glucans. Our results indicate that vaccination with Bm Delta-pgm induces a robust memory cellular immune response but no antibody production against the O-antigen. Cross protection experiments show that this new vaccine protects against B. abortus and B. suis raising the possibility that Bm Delta-pgm could be used as a universal vaccine for the most important Brucella species.
Asunto(s)
Vacuna contra la Brucelosis , Brucella melitensis , Brucelosis , Femenino , Ratones , Animales , Ovinos , Bovinos , Humanos , Porcinos , Brucella melitensis/genética , Fosfoglucomutasa/genética , Cabras , Antígenos O , Brucelosis/prevención & control , Brucella abortusRESUMEN
Brucella parasitize the macrophage where is able to replicate and modulate the immune response in order to establish a chronic infection. The most adequate response to control and eliminate Brucella infection is a type 1 (Th1) cell-mediated effector immunity. Research in immune response of B. melitensis-infected goats is relatively scarce. In this study, we first evaluated changes in the gene expression of cytokines, a chemokine (CCL2) and the inducible nitric oxide synthase (iNOS) of goat macrophage cultures derived from monocytes (MDMs) infected for 4 and 24 h with Brucella melitensis strain 16 M. TNFα, IL-1ß and iNOS, and IL-12p40, IFNγ and also iNOS were significantly expressed (p < 0.05) at 4 and 24 h respectively, in infected compared to non-infected MDMs. Therefore, the in vitro challenge of goat MDMs with B. melitensis promoted a transcriptional profile consistent with a type 1 response. However, when the immune response to B. melitensis infection was contrasted between MDM cultures phenotypically restrictive or permissive to intracellular multiplication of B. melitensis 16 M, it was observed that the relative IL-4 mRNA expression was significantly higher in permissive macrophage cultures with respect to restrictive cultures (p < 0.05), independently of the time p.i. A similar trend, although non-statistical, was recorded for IL-10, but not for pro-inflammatory cytokines. Thus, the up-expression profile of inhibitory instead of pro-inflammatory cytokines could explain, in part, the difference observed in the ability to restrict intracellular replication of Brucella. In this sense, the present results make a significant contribution to the knowledge of the immune response induced by B. melitensis in macrophages of its preferential host species.
Asunto(s)
Brucella melitensis , Brucelosis , Animales , Cabras , Macrófagos , Brucella melitensis/genética , Brucella melitensis/metabolismo , Brucelosis/metabolismo , Citocinas/metabolismoRESUMEN
BACKGROUND: Epidemiological studies are important tools to assess the diversity of Brucella isolates and to estimate their epidemiological relationship among isolates from different geographical origins. In this study the MLVA16 (multiple-locus variable number tandem repeat analysis based on 16 loci) was employed to investigate the diversity of Brucella spp. Isolated from humans and animals for epidemiological purposes and to determine the most common Brucella genotypes in Iran. METHODS: We designed a molecular-based study to evaluate the potential reservoirs of human brucellosis. After isolation and identification of 54 Brucella spp human and animal specimens from three regions of Iran, bacterial genomic DNA was extracted MLVA with three panel was used for the genotyping of isolates. The size of PCR products were analyzed and converted to repeat unit numbers using a published allele numbering system and data set was imported into Bionumerics. RESULTS: Three isolates (5.55%) were identified as Brucella abortus and 51 (94.44%) as Brucella melitensis. Two isolates of Brucella abortus were from humans and one from an animal. Thirty-four Brucella melitensis isolates were from humans and 17 from animals. Using MLVA16-genotyping, 54 isolates with genetic similarity coefficient of 80% were divided into 46 genotypes and 22 genotypes were represented by a single isolate, while 4, 2, 1 and 2 genotypes were represented by 2, 3, 4 and 7 isolates, respectively. The most prevalent genotype was represented by 14 isolates. There were two other frequent genotypes each represented by seven isolates, among which only one was restricted to a geographic region. Discriminatory power for each locus was determined in this study and panel 2B shows the high discretionary power [Bruce04 (0.837), Bruce30 (0.806), Bruce 09 (0.787), Bruce 07 (0.772), Bruce16 (0.766)]. CONCLUSION: MLVA16 analysis of 54 Brucella isolates showed high level polymorphism in their genotypes. Only two genotypes, each observed in seven isolates, were related to one another and only one of these genotypes were found in to two separate regions.
Asunto(s)
Brucella melitensis , Brucelosis , Animales , Brucella melitensis/genética , Variación Genética , Genotipo , Humanos , Irán , Repeticiones de Minisatélite/genéticaRESUMEN
ABSTRACT Background: Epidemiological studies are important tools to assess the diversity of Brucella isolates and to estimate their epidemiological relationship among isolates from different geographical origins. In this study the MLVA16 (multiple-locus variable number tandem repeat analysis based on 16 loci) was employed to investigate the diversity of Brucella spp. Isolated from humans and animals for epidemiological purposes and to determine the most common Brucella genotypes in Iran. Methods: We designed a molecular-based study to evaluate the potential reservoirs of human brucellosis. After isolation and identification of 54 Brucella spp human and animal specimens from three regions of Iran, bacterial genomic DNA was extracted MLVA with three panel was used for the genotyping of isolates. The size of PCR products were analyzed and converted to repeat unit numbers using a published allele numbering system and data set was imported into Bionumerics. Results: Three isolates (5.55%) were identified as Brucella abortus and 51 (94.44%) as Brucella melitensis. Two isolates of Brucella abortus were from humans and one from an animal. Thirty-four Brucella melitensis isolates were from humans and 17 from animals. Using MLVA16-genotyping, 54 isolates with genetic similarity coefficient of 80% were divided into 46 genotypes and 22 genotypes were represented by a single isolate, while 4, 2, 1 and 2 genotypes were represented by 2, 3, 4 and 7 isolates, respectively. The most prevalent genotype was represented by 14 isolates. There were two other frequent genotypes each represented by seven isolates, among which only one was restricted to a geographic region. Discriminatory power for each locus was determined in this study and panel 2B shows the high discretionary power [Bruce04 (0.837), Bruce30 (0.806), Bruce 09 (0.787), Bruce 07 (0.772), Bruce16 (0.766)]. Conclusion: MLVA16 analysis of 54 Brucella isolates showed high level polymorphism in their genotypes. Only two genotypes, each observed in seven isolates, were related to one another and only one of these genotypes were found in to two separate regions.
Asunto(s)
Humanos , Animales , Brucelosis , Brucella melitensis/genética , Variación Genética , Repeticiones de Minisatélite/genética , Genotipo , IránRESUMEN
Brucellosis is an infectious disease that affects practically all species of mammals, including human, and is a major zoonosis worldwide. Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in phagocytic and nonphagocytic cells such as trophoblast and epithelial cells. Among the six recognized species of the genus Brucella, Brucella melitensis is the main etiological agent involved in goat brucellosis and is also the most pathogenic for human. It causes significant losses in livestock production as a result of abortions, metritis, infertility, and birth of weak animals. Outer membrane proteins (OMPs) are exposed on the bacterial surface and are in contact with cells and effectors of the host immune response, whereby they could be important virulence factors of Brucella species. To evaluate this hypothesis, the gene encoding for the major outer membrane protein Omp31 was amplified, cloned into pUC18 plasmid, and inactivated by inserting a kanamycin cassette, rendering pLVM31 plasmid which was transformed into B. melitensis wild-type strain to obtain LVM31 mutant strain. The Outer membrane (OM) properties of the mutant strain were compared with B. melitensis Bm133 wild-type and B. melitensis Rev1 vaccine strains, in assessing its susceptibility to polymyxin B, sodium deoxycholate, and nonimmune serum. The mutant strain was assessed in vitro with survival assays in murine macrophages J774.A1 and HeLa cells. Our results demonstrate that LVM31 mutant is more susceptible to polymyxin B, sodium deoxycholate, and nonimmune serum than control strains; moreover, Omp31 mutation caused a decrease in the internalization and a significant decrease in the intracellular survival compared with the reference strains in both cell lines. These results allow us to conclude that Omp31 is important for maintaining OM integrity, but also it is necessary for bacterial internalization, establishment and development of an optimal replication niche, and essential for survival and intracellular multiplication.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Brucella melitensis/patogenicidad , Brucelosis/patología , Macrófagos/microbiología , Animales , Brucella melitensis/genética , Brucella melitensis/metabolismo , Brucelosis/microbiología , Línea Celular Tumoral , Ácido Desoxicólico/farmacología , Células HeLa , Humanos , Macrófagos/inmunología , Ratones , Pruebas de Sensibilidad Microbiana , Mutación/genética , Plásmidos/genética , Polimixina B/farmacología , Factores de Virulencia/metabolismoRESUMEN
Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Brucella spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brocella DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8% (133/180) of the tested sera using primers (B4/B5) derived from a gene encoding the 31-kDa Brucella abortus antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8% (115/180) of the samples using Brucella abortus-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4% (8/180) of the tested samples using Brucella melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7%, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82%, and specificity was similar to that previous reported. This is the first report of a high frequency of Brucella abortus in patients suspicious of Brucellosis from the Zanjan province.
Asunto(s)
Brucella abortus/aislamiento & purificación , Brucella melitensis/aislamiento & purificación , Brucelosis/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Suero/microbiología , Adolescente , Adulto , Anciano , Animales , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Brucella abortus/genética , Brucella melitensis/genética , Elementos Transponibles de ADN , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Femenino , Humanos , Irán , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Brucella spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brocella DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8% (133/180) of the tested sera using primers (B4/B5) derived from a gene encoding the 31-kDa Brucella abortus antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8% (115/180) of the samples using Brucella abortus-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4% (8/180) of the tested samples using Brucella melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7%, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82%, and specificity was similar to that previous reported. This is the first report of a high frequency of Brucella abortus in patients suspicious of Brucellosis from the Zanjan province.
Asunto(s)
Adolescente , Adulto , Anciano , Animales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Brucella abortus/aislamiento & purificación , Brucella melitensis/aislamiento & purificación , Brucelosis/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Suero/microbiología , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Brucella abortus/genética , Brucella melitensis/genética , Elementos Transponibles de ADN , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Irán , Sensibilidad y EspecificidadRESUMEN
Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Brucella spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brocella DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8% (133/180) of the tested sera using primers (B4/B5) derived from a gene encoding the 31-kDa Brucella abortus antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8% (115/180) of the samples using Brucella abortus-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4% (8/180) of the tested samples using Brucella melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7%, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82%, and specificity was similar to that previous reported. This is the first report of a high frequency of Brucella abortus in patients suspicious of Brucellosis from the Zanjan province.
Asunto(s)
Humanos , Animales , Masculino , Femenino , Adolescente , Adulto Joven , Adulto , Anciano , Persona de Mediana Edad , Brucella abortus/aislamiento & purificación , Brucella melitensis/aislamiento & purificación , Brucelosis/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Suero/microbiología , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Brucella abortus/genética , Brucella melitensis/genética , Elementos Transponibles de ADN , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Irán , Sensibilidad y EspecificidadRESUMEN
Some of the mechanisms underlying the invasion and intracellular survival of B. melitensis are still unknown, including the role of a subfamily of NUDIX enzymes, which have been described in other bacterial species as invasins and are present in Brucella spp. We have generated a mutation in the coding gene of one of these proteins, the invA gene (BMEI0215) of B. melitensis strain 133, to understand its role in virulence. HeLa cell invasion results showed that mutant strain survival was decreased 5-fold compared with that of the parental strain at 2 h pi (P<0.001). In a goat macrophage infection assay, mutant strain replication was 8-fold less than in the parental strain at 24 h pi (P<0.001); yet, at 48 h pi, no significant differences in intracellular replication were observed. Additionally, colocalization of the invA mutant with calregulin was significantly lower at 24 h pi compared with that of the parental strain. Furthermore, the mutant strain exhibited a low level of colocalization with cathepsin D, which was similar to the parental strain colocalization at 24 h pi. In vivo infection results demonstrated that spleen colonization was significantly lower with the mutant than with the parental strain. The immune response, measured in terms of antibody switching and IFN-γ transcription, was similar for Rev1 and infection with the mutant, although it was lower than the immune response elicited by the parental strain. Consequently, these results indicate that the invA gene is important during invasion but not for intracellular replication. Additionally, mutation of the invA gene results in in vivo attenuation.
Asunto(s)
Proteínas Bacterianas/metabolismo , Brucella melitensis/enzimología , Brucelosis/microbiología , Animales , Proteínas Bacterianas/genética , Brucella melitensis/genética , Brucella melitensis/patogenicidad , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , VirulenciaRESUMEN
The immunogenicity of a DNA vaccine containing an open reading frame (ORF) of genomic island 3 (GI-3), specific for Brucella abortus and Brucella melitensis, has been examined. Intramuscular injection of plasmid DNA carrying the open reading frame with homology to an ABC-type transporter (pV278a) into BALB/c mice elicited both humoral and cellular immune responses. Mice injected with pV278a had a dominant immunoglobulin G2a (IgG2a) response. This DNA vaccine elicited a T-cell-proliferative response and induced significant levels of interferon gamma (INF-γ) upon restimulation with recombinant 278a protein. Upon stimulation with an appropriate recombinant protein or crude Brucella protein, the vaccine did not induce IL-4, suggesting a typical T-helper (TH1) response. Furthermore, the vaccine induced protection in BALB/c mice when challenged with the virulent strain Brucella abortus 2308. Taken together, these data suggest that DNA vaccination offers an improved delivery of the homologous of an ABC-type transporter antigen, and provides the first evidence of a protective effect of this antigen in the construction of vaccines against B. abortus.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/inmunología , Vacuna contra la Brucelosis/inmunología , Brucelosis/prevención & control , Islas Genómicas , Vacunas de ADN/inmunología , Transportadoras de Casetes de Unión a ATP/genética , Animales , Anticuerpos Antibacterianos/sangre , Vacuna contra la Brucelosis/genética , Brucella abortus/genética , Brucella melitensis/genética , Femenino , Inmunidad Celular , Inmunidad Humoral , Inmunoglobulina G/sangre , Interferón gamma/inmunología , Ratones , Ratones Endogámicos BALB C , Sistemas de Lectura Abierta , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Células TH1/inmunología , Vacunas de ADN/genéticaRESUMEN
Brucellosis has been reported mainly among pregnant women, and it may lead to spontaneous abortion, intrauterine fetal death, or delivery of an infected neonate. Transmission through breast milk has also been described, but congenital cases are not commonly reported. We present the clinical findings, laboratory studies, treatment, and final outcome of a late prenatal transmission from a mother to her term infant of Brucella melitensis biovar 1. Because the maternal disease was undetected due to lack of clinical suspicion, diagnosis was made possible only by the results of infant blood cultures. Differential diagnosis of fever of unknown origin (FUO) misdiagnosed could result, as in our case, in the administration of inappropriate antimicrobial therapy. Primary health care physicians should be alerted to the clinical and laboratory findings of this infection, and pregnant women should routinely be tested serologically in areas where brucellosis is still a problem.
Asunto(s)
Brucella melitensis/aislamiento & purificación , Brucelosis/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Brucella melitensis/genética , Brucelosis/diagnóstico , Brucelosis/tratamiento farmacológico , Diagnóstico Diferencial , Femenino , Humanos , Recién Nacido , Embarazo , Adulto JovenRESUMEN
Brucella melitensis is highly infectious for humans and can be transmitted to humans in a number of epidemiological contexts. Within the context of an ongoing brucellosis surveillance project, an outbreak at a Peruvian police officer cafeteria was discovered, which led to active surveillance (serology, blood culture) for additional cases among 49 police officers who had also eaten there. The cohort was followed up to 18 months regardless of treatment or symptoms. Active surveillance estimated the attack rate at 26.5% (13 of 49). Blood cultures from four cases were positive; these isolates were indistinguishable using multiple locus variable number tandem repeat analysis. This investigation indicates the importance of case tracking and active surveillance for brucellosis in the context of potential common source exposure. These results provide rationale for public health investigations of brucellosis index cases including the bioterrorism-related dissemination of Brucella.
Asunto(s)
Brucelosis/epidemiología , Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/epidemiología , Adulto , Animales , Brucella melitensis/genética , Brucella melitensis/aislamiento & purificación , Brucelosis/microbiología , Queso/microbiología , Trazado de Contacto , Femenino , Microbiología de Alimentos , Cabras/microbiología , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional , Pasteurización , Perú/epidemiología , Policia , Factores de Tiempo , Adulto JovenRESUMEN
The immunogenicity of two DNA vaccines encoding open reading frames (ORFs) of genomic island 3 (GI-3), specific for Brucella abortus and Brucella melitensis, has been examined. Intramuscular injection of plasmid DNA carrying the BAB1_0263 and BAB1_0278 genes (pVF263 and pVF278, respectively) into BALB/c mice elicited both humoral and cellular immune responses. Mice injected with pVF263 or pVF278 had a dominant immunoglobulin G2a (IgG2a) response. In addition, both DNA vaccines elicited a T-cell-proliferative response, but only pVF263 induced significant levels of interferon gamma (INF-γ) upon restimulation with recombinant 263 protein. Neither DNA vaccine induced interleukin (IL)-10, nor IL-4, upon stimulation with an appropriate recombinant protein or crude Brucella protein, suggesting the induction of a typical T-helper 1 (Th1)-dominated immune response. Furthermore, the pVF278 DNA vaccines induced protection in BALB/c mice against challenge with the virulent strain B. abortus 2308. Taken together, these data suggest that DNA vaccination offers an improved delivery strategy for the BAB1_0278 antigen, and provide the first evidence of a protective effect of this antigen.
Asunto(s)
Antígenos Bacterianos/inmunología , Vacuna contra la Brucelosis/inmunología , Brucella abortus/inmunología , Brucella melitensis/inmunología , Brucelosis/prevención & control , Vacunas de ADN/inmunología , Animales , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/genética , Vacuna contra la Brucelosis/administración & dosificación , Brucella abortus/genética , Brucella melitensis/genética , Proliferación Celular , Femenino , Inmunoglobulina G/sangre , Interferón gamma/metabolismo , Ratones , Ratones Endogámicos BALB C , Sistemas de Lectura Abierta , Linfocitos T/inmunología , Células TH1/inmunología , Vacunas de ADN/administración & dosificaciónRESUMEN
The outer membrane vesicles (OMVs) from smooth B. melitensis 16 M and a derived rough mutant, VTRM1 strain, were purified and characterized with respect to protein content and induction of immune responses in mice. Proteomic analysis showed 29 proteins present in OMVs from B. melitensis 16 M; some of them are well-known Brucella immunogens such as SOD, GroES, Omp31, Omp25, Omp19, bp26, and Omp16. OMVs from a rough VTRM1 induced significantly higher expression of IL-12, TNFα, and IFNγ genes in bone marrow dendritic cells than OMVs from smooth strain 16 M. Relative to saline control group, mice immunized intramuscularly with rough and smooth OMVs were protected from challenge with virulent strain B. melitensis 16 M just as well as the group immunized with live strain B. melitensis Rev1 (P < 0.005). Additionally, the levels of serum IgG2a increased in mice vaccinated with OMVs from rough strain VTRM1 consistent with the induction of cell-mediated immunity.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/inmunología , Brucella melitensis/inmunología , Brucelosis/inmunología , Brucelosis/prevención & control , Animales , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas de la Membrana Bacteriana Externa/aislamiento & purificación , Vacuna contra la Brucelosis/inmunología , Brucella melitensis/genética , Citocinas/biosíntesis , Células Dendríticas/inmunología , Femenino , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Ratones , Ratones Endogámicos BALB C , ProteómicaRESUMEN
The genomic island 3 (GI-3) shared by Brucella melitensis and Brucella abortus contains 29 genes encoding mostly unknown proteins. Within this island, the open reading frames (ORFs) BAB1_0278 and BAB1_0263 are present, BAB1_0278 encodes a hypothetical protein of 64 amino acids sharing a domain with the GcrA superfamily, whereas the amino acid sequence of BAB1_0263 showed 42% identity with an iron regulated Lsr2 protein. We obtained one deletion mutant for each one of these ORFs present within the B. abortus GI-3 named BA-278 and BA-263, respectively. Both mutants were evaluated with respect to their ability to invade and replicate in nonprofessional and professional phagocytes (HeLa and J774.A1 cells) and their virulence in mice. Both mutants invaded efficiently HeLa and J774. A1 cells, however, 48-h post-infection the BA-278 mutant showed a lower intracellular persistence. The deletion of the ORF BAB1_0278, also affected the persistence of B. abortus in the spleens of mice, unlike to the deletion of the ORF BAB1_0263. These results allow us to conclude that BAB1_0278 ORF contributes to virulence of Brucella, since it is necessary to establish an optimal infectious process.
Asunto(s)
Brucella abortus/genética , Brucella abortus/patogenicidad , Brucelosis/veterinaria , Islas Genómicas , Animales , Brucella melitensis/genética , Células HeLa , Humanos , Ratones , Ratones Endogámicos BALB C , Sistemas de Lectura Abierta , Eliminación de Secuencia , Virulencia , Factores de Virulencia/genéticaRESUMEN
Consumption of inadequately pasteurized dairy products is the most common means of transmission of brucellosis. This report describes two foodborne outbreaks that occurred in families infected after consumption of fresh home-made cheese bought in different Argentine provinces. High resolution variable number of tandem repeats (VNTR)-based analysis revealed two well-defined groups comprising essentially identical profiles and corresponding to the two different outbreaks. Similar clinical findings in members of the same family could indicate that the differential virulence of different bacterial clones, as indicated by VNTR data, could have influenced the course of the disease. We observed the importance of adequate treatment in early stages of the disease; combination therapy and extended treatment for 6 weeks or longer yielded significantly better results. The risk of the foodborne transmission of this zoonotic disease and disease prevention should be considered.
Asunto(s)
Técnicas de Tipificación Bacteriana , Brucella melitensis/genética , Brucelosis/epidemiología , Dermatoglifia del ADN , Brotes de Enfermedades , Salud de la Familia , Repeticiones de Minisatélite , Adolescente , Adulto , Anciano , Animales , Argentina/epidemiología , Brucella melitensis/clasificación , Brucella melitensis/aislamiento & purificación , Brucelosis/microbiología , Brucelosis/patología , Niño , Análisis por Conglomerados , Femenino , Enfermedades Transmitidas por los Alimentos/epidemiología , Genotipo , Humanos , Masculino , Adulto JovenRESUMEN
The multiple-locus variable-number repeat analysis of 90 human Brucella melitensis isolates from a large urban area in central Peru revealed variations at 4 (Bruce07, Bruce09, Bruce18, and Bruce42) out of 16 loci investigated, of which 1 (Bruce42) also is used for species identification. Ten genotypes were identified, separated by the number of Bruce42 repeats into two groups that may have distinct phenotypic characteristics. Whereas genotypes with five or six Bruce42 repeats were cultured mainly from adult patients, genotypes with three Bruce42 repeats were isolated from children and young adolescents as well as from adults. In addition, the isolates with three Bruce42 repeats were obtained more often from patients with splenomegaly (P = 0.02) or hepatomegaly (P = 0.006). An annual variation in the diversity of genotypes was observed, possibly reflecting changes in sources of fresh dairy products, supply routes to city shops and markets, and the movement of infected dairy goat herds.
Asunto(s)
Brucella melitensis/clasificación , Brucella melitensis/aislamiento & purificación , Brucelosis/epidemiología , Brucelosis/microbiología , ADN Bacteriano/genética , Polimorfismo Genético , Animales , Técnicas de Tipificación Bacteriana , Brucella melitensis/genética , Análisis por Conglomerados , Dermatoglifia del ADN , Productos Lácteos/microbiología , Genotipo , Cabras/microbiología , Hospitales , Humanos , Repeticiones de Minisatélite , Epidemiología Molecular , Perú/epidemiología , Población UrbanaRESUMEN
Recent human Brucella melitensis isolates from Peru were genotyped by multiple locus variable number repeat analysis. All 24 isolates originated from hospitalized patients living in the central part of Peru and consisted of six genomic groups comprising two to four isolates and nine unique genotypes. The isolates were most closely related to the two previously genotyped isolates from Mexico, with a maximum distance of 2 to 4. The Peruvian strains were clearly distinct from the East and West Mediterranean groups of B. melitensis genotypes, suggesting that they may constitute a unique Latin American cluster.