Diagnóstico etiológico de aborto infeccioso bovino por PCR

Infectious abortion is a significant cause of reproductive failure and economic losses in cattle. The goal of this study was to detect nucleic acids of several infectious agents known to cause abortion including Arcanobacterium pyogenes, Bovine Herpesvirus 1, Brucella abortus, Campylobacter fetus subsp. venerealis, Chlamydophila abortus, Leptospira sp., Listeria monocytogenes, Salmonella sp., Mycoplasma bovis, Mycoplasma bovigenitalium, Neospora caninum, and Tritrichomonas foetus. Tissue homogenates from 42 fetuses and paraffin-embedded tissues from 28 fetuses and 14 placentas/endometrium were included in this study. Brucella abortus was detected in 14.2% (12/84) of the samples. Salmonella sp. DNA was amplified from 2 fetuses, and there was one positive for Neospora caninum, and another for Listeria monocytogenes. This PCR-based approach resulted in identification of the etiology in 19% of samples, or 20% if considered fetal tissues only.Aborto infeccioso é uma causa significativa de falhas reprodutivas e perdas econômicas na bovinocultura. O objetivo deste estudo foi detectar ácidos nucleicos de vários agentes infecciosos reconhecidos como causadores de aborto, incluindo-se Arcanobacterium pyogenes, Herpesvirus bovino tipo 1, Brucella abortus, Campylobacter fetus subsp. venerealis, Chlamydophila abortus, Leptospira sp., Listeria monocytogenes, Salmonella sp., Mycoplasma bovis, Mycoplasma bovigenitalium, Neospora caninum e Tritrichomonas foetus. Homogenados de tecidos de 42 fetos e tecidos incluídos em parafina de 28 fetos e 14 placentas/endométrio foram incluídos neste estudo. Brucella abortus foi detectada em 14,2% (12/84) das amostras. DNA de Salmonella sp. foi amplificado de dois fetos e houve um feto positivo para Neospora caninum e outro para Listeria monocytogenes. Essa metodologia baseada em PCR resultou na identificação da etiologia em 19% das amostras ou 20% se considerados somente os tecidos fetais

Resistance pattern, MLVA8 genotype and the spatial localization of the <i>B</i>. <i>abortus</i> strains that showed resistance or intermediate profile to at least one of the tested antibiotics.

<p>The states sampled are highlighted in gray. The number inside the state represents the number of sampled <i>B</i>. <i>abortus</i> strains from that state. The shape of the symbols used represents the MLVA8-genotype observed for the strains with resistant or intermediate profile. The color of the symbols represents the resistance pattern of the nine <i>B</i>. <i>abortus</i> that were resistant or intermediate to at least one of the tested antimicrobials, according to the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132532#pone.0132532.t002" target="_blank">Table 2</a>. CIP: ciprofloxacin; DOX: doxycycline; EST: streptomycin; GEN, gentamicin; OFX, ofloxacin; RIF, rifampicin; SXT, trimethoprim-sulfamethoxazole. (R): resistant; (I): intermediate.</p

Resistance pattern, MLVA8 genotype and the spatial localization of the <i>B</i>. <i>abortus</i> strains that showed resistance or intermediate profile to at least one of the tested antibiotics.

<p>The states sampled are highlighted in gray. The number inside the state represents the number of sampled <i>B</i>. <i>abortus</i> strains from that state. The shape of the symbols used represents the MLVA8-genotype observed for the strains with resistant or intermediate profile. The color of the symbols represents the resistance pattern of the nine <i>B</i>. <i>abortus</i> that were resistant or intermediate to at least one of the tested antimicrobials, according to the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132532#pone.0132532.t002" target="_blank">Table 2</a>. CIP: ciprofloxacin; DOX: doxycycline; EST: streptomycin; GEN, gentamicin; OFX, ofloxacin; RIF, rifampicin; SXT, trimethoprim-sulfamethoxazole. (R): resistant; (I): intermediate.</p

Distribution of the susceptibility profile to seven antimicrobials for the 147 <i>B</i>. <i>abortus</i> strains isolated from cattle in Brazil, 1977–2009, according to the year of isolation.

<p>^a Suceptible</p><p>^b Resistant</p><p>^c Intermediate</p><p>^d Not known</p><p>Distribution of the susceptibility profile to seven antimicrobials for the 147 <i>B</i>. <i>abortus</i> strains isolated from cattle in Brazil, 1977–2009, according to the year of isolation.</p

Susceptibility profile of <i>Brucella abortus</i> strains isolated from cattle in Brazil, 1977–2009.

<p>^a CIP: ciprofloxacin, DOX: doxycyclin, EST: streptomycin, GEN, gentamicin, OFX, ofloxacin, RIF: rifampicin, SXT, trimethoprim-sulfamethoxazole</p><p>^bSusceptibility profiles to seven antimicrobials tested</p><p>^cNumber of strains with identical susceptibility profile</p><p>^dSusceptible</p><p>^eIntermediate</p><p>^fResistant.</p><p>Susceptibility profile of <i>Brucella abortus</i> strains isolated from cattle in Brazil, 1977–2009.</p

Reduced Susceptibility to Rifampicin and Resistance to Multiple Antimicrobial Agents among <i>Brucella abortus</i> Isolates from Cattle in Brazil

<div><p>This study aimed to determine the susceptibility profile of Brazilian <i>Brucella abortus</i> isolates from cattle to eight antimicrobial agents that are recommended for the treatment of human brucellosis and to correlate the susceptibility patterns with origin, biotype and MLVA16-genotype of the strains. Screening of 147 <i>B</i>. <i>abortus</i> strains showed 100% sensitivity to doxycycline and ofloxacin, one (0.68%) strain resistant to ciprofloxacin, two strains (1.36%) resistant to streptomycin, two strains (1.36%) resistant to trimethoprim-sulfamethoxazole and five strains (3.40%) resistant to gentamicin. For rifampicin, three strains (2.04%) were resistant and 54 strains (36.73%) showed reduced sensitivity. Two strains were considered multidrug resistant. In conclusion, the majority of <i>B</i>. <i>abortus</i> strains isolated from cattle in Brazil were sensitive to the antimicrobials commonly used for the treatment of human brucellosis; however, a considerable proportion of strains showed reduced susceptibility to rifampicin and two strains were considered multidrug resistant. Moreover, there was no correlation among the drug susceptibility pattern, origin, biotype and MLVA16-genotypes of these strains.</p></div

Minimal Inhibitory Concentration (MIC₅₀, MIC₉₀ and range) values of <i>Brucella abortus</i> strains isolated from cattle in Brazil, 1977–2009, to eight antimicrobials used in the treatment of human brucellosis.

<p>^aVariation of MIC values (number of dilution variations) for every antimicrobial</p><p>^bMinimum Inhibitory Concentration required to inhibit the growth of 50% of the strains</p><p>^cMinimum Inhibitory Concentration required to inhibit the growth of 90% of the strains</p><p>^dNumber of sensitive strains in the MIC established</p><p>^eBreakpoint of resistance for <i>Brucella</i> spp. strains (μg/mL)</p><p>^fNumber of resistant strains</p><p>^gPercentage of resistant strains</p><p>^hThe breakpoints for rifampin are: resistance ≥ 4.0 μg/mL, intermediate 2.0 μg/mL and sensitivity ≤ 1.0 μg/mL.</p><p>Minimal Inhibitory Concentration (MIC₅₀, MIC₉₀ and range) values of <i>Brucella abortus</i> strains isolated from cattle in Brazil, 1977–2009, to eight antimicrobials used in the treatment of human brucellosis.</p