Relevance of in vitro antimicrobial susceptibility of Brucella melitensis to relapse rate in human brucellosis

Ariza, Javier; Bosch, J.; Gudiol, Francisco; Liñares, Josefina; Viladrich, Pedro F.; Martin, R. Russell

doi:10.1128/aac.30.6.958

Cited by 58 publications

(32 citation statements)

References 27 publications

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“…Streptomycin, co-trimoxazole, and rifampin demonstrated somewhat higher MICs (Table 1); however, their MIC90s were similar to their MIC50s, representing a limited susceptibility distribution pattern. The MIC of streptomycin remained essentially unchanged from that observed by many investigators for the past half century (3,12). Rifampin MIC90s in previous studies were reported to range from 0.02 to 0.10 ,ug/ml, values confirmed again by our findings (8,10,12).…”

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confidence: 81%

In vitro susceptibility of Brucella melitensis to antibiotics

Rubinstein

Lang

Shasha

et al. 1991

Antimicrob Agents Chemother

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The in vitro susceptibilities of 86 recent clinical isolates of Brucella melitensis to minocycline, streptomycin, co-trimoxazole, rifampin, and six fluoroquinolones were determined. Minocycline exhibited the lowest MIC and was followed by rifampin and streptomycin. Among the quinolones, WIN 57273 and ciprofloxacin were the most active agents. No antibiotic combination of these agents exhibited synergy against 15 selected isolates. In killing rate experiments, streptomycin exhibited the most rapid kill (<12 h), while a complete kill with minocycline, rifampin, and ciprofloxacin was delayed up to 48 h. The combinations of streptomycin with each of minocycline, rifampin, or ciprofloxacin exhibited the fastest kills (within 2 h), while with the other combinations, a complete kill was delayed up to 96 h. These results demonstrate the discrepancy between the results of various in vitro methods in evaluating the antibiotic susceptibility of B. melitensis.Human brucellosis is an important ongoing medical problem. The Mediterranean basin is one of the most heavily afflicted regions (7). Despite the availability of many antibacterial agents, the complete cure of the infection with prevention of the frequent relapses is still an unattainable goal (7). The new fluoroquinolone antibacterial agents, because of their broad spectrum of bactericidal activity against a variety of gram-negative bacteria and because of their favorable intracellular penetration, could potentially be candidates for the therapy of brucellosis (13, 19). We therefore tested the in vitro activities of several fluoroquinolones (pefloxacin, ofloxacin, ciprofloxacin, fleroxacin, sparfloxacin, and WIN 57273) and compared them with the activities of the conventional anti-Brucella antibiotics: tetracycline, streptomycin, rifampin, and sulfamethoxazole-trimethoprim (co-trimoxazole), recommended for the therapy of brucellosis. In addition, we also studied the possible synergistic effects of several combinations of these antibiotics.Bacteria. Eighty-six Brucella melitensis strains isolated from patients at three different geographical districts in Israel were used. The identities of all B. melitensis strains were confirmed (by Menachem Banai) in the National Brucella Reference Laboratory by the Stamp stain appropriate biochemical reactions and by phage typing (2). Stock strains were kept frozen in small aliquots at -80°C and were kept between experiments on agar slants.Antibiotics. Antibiotics were obtained from their manufacturers as laboratory powders and were reconstituted in their recommended diluents to yield stock solutions of 1,000 ,u.g/ml that were kept at -70°C. Minocycline (Lederle, Pearl River, N.Y.) was used as a representative of the tetracycline family. Streptomycin sulfate (Teva, Jerusalem, Israel), sulfamethoxazole-trimethoprim (Wellcome, Beckenham, United Kingdom), rifampin (Ciba-Geigy, Basel, Switzerland), ciprofloxacin (Bayer AG, Leverkusen, Germany), ofloxacin (Hoechst AG, Frankfurt, Germany), pefloxacin and sparfloxacin (Rhone-Poulenc-Rorer, ...

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supporting

confidence: 81%

In vitro susceptibility of Brucella melitensis to antibiotics

Rubinstein

Lang

Shasha

et al. 1991

Antimicrob Agents Chemother

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“…Quite recently, matrix-assisted laser desorption/ionization mass spectrometry and surface enhanced laser desorption/ionization mass spectrometry proved to be of benefit in the direct identification of members of the genus Brucella from culture plates and blood culture bottles [53,54]. However, comprehensive databases including characteristic protein profiles of Brucella species are missing, which currently restricts the use of these upcoming technologies in clinical microbiology laboratories.Bacteria isolated during relapse show the same antimicrobial susceptibility pattern as isolates obtained in the primary episode of the disease, and most of the relapsed cases respond well to a repeated course of the standard antibiotic therapy [55]. Hence, antibiotic drug resistance does not essentially contribute to treatment failures and relapses, and in vitro susceptibility testing of Brucella isolates is therefore of questionable clinical significance.…”

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confidence: 99%

Implications of laboratory diagnosis on brucellosis therapy

Dahouk

Nöckler

2011

Expert Review of Anti-infective Therapy

167

131

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Brucellosis is one of the world's most widespread bacterial zoonoses, leading to tremendous economic losses in endemic regions and serious complaints in affected patients. The infection may be transmitted by direct animal contact, but is usually acquired through the consumption of contaminated food products of animal origin, mainly via unpasteurized goat's milk and cheese. Furthermore, brucellosis is the most common bacterial laboratory-acquired infection worldwide [1].Although many national and international programs have been established to eradicate the pathogen and control its spreading in animal husbandry, brucellosis is still a re-emerging disease. The surveillance of animal brucellosis is difficult due to bacterial persistence in wildlife and environmental reservoirs, with consecutive spill-over to domestic animals [2].Brucellosis is caused by members of the genus Brucella (B.), which are gram-negative, facultative intracellular coccobacilli that were historically differentiated by their preferred animal host, varying pathogenicity and a few selected phenotypic traits. The genus comprises six classical species: B. melitensis bv 1-3 (primarily isolated from sheep and goats); B. abortus bv 1-6 and 9 (from cattle and other Bovidae); B. suis bv 1-3 (from pigs), bv 4 (from reindeer), bv 5 (from small rodents); B. canis (from dogs); B. ovis (from sheep); and B. neotomae (from desert wood rats). Recently, two novel species of marine origin, B. pinnipedialis (isolated from seals) and B. ceti (from dolphins and whales) [3], B. microti isolated from the common vole (Microtus arvalis) [4], red foxes (Vulpes vulpes) [5] and from soil [6], and B. inopinata isolated from a breast implant wound of a 71-year-old female patient [7] have been described. In the past, a lot of atypical Brucella strains arose. These could represent novel species or lineages of already described species, for example various Brucella strains originating from wild native rodent species in North Queensland, Australia [8], a novel Brucella isolate in association with two cases of stillbirth in nonhuman primates [9], and a B. inopinata-like strain (BO2), which was isolated from a lung biopsy of a 52-year-old Australian patient suffering from chronic destructive pneumonia [10].Physicians' awareness of the infection is very poor in many countries, and most cases correctly identified are clinically advanced. Because of its protean clinical manifestations, human brucellosis can be easily confused with other infectious and noninfectious diseases, leading to diagnostic delays and late onset of therapy. The isolation of the fastidious organisms is often unsuccessful or takes a long time, which is why the presumptive clinical diagnosis is usually confirmed by Brucellosis is a worldwide zoonosis with a huge economic impact on animal husbandry and public health. The diagnosis of human brucellosis can be protracted because the disease primarily presents as fever of unknown origin with unspecific clinical signs and symptoms. The isolation rate of the fastidiou...

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“…is not recommended since the susceptibility pattern of wild-type Brucella spp. is fairly predictable, the isolates are fastidious, and the organisms are a potential cause of laboratory-acquired infection (3,12,17). In addition, Brucella spp.…”

mentioning

confidence: 99%

“…Trimethoprim-sulfamethoxazole is recommended as alternative therapy (28), but use of fluoroquinolone therapy is controversial (12,18,25). Although there has been little or no resistance reported to routinely prescribed antimicrobials for brucellosis, relapse is still common (3,5,22,25), and development of laboratory-confirmed rifampin resistance has been reported (11).Brucella suis, Brucella melitensis, and Brucella abortus are considered potential agents of bioterrorism (6, 24). As with other potential bacterial agents of bioterrorism, engineered antimicrobial resistance is a concern.…”

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confidence: 99%

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Effect of Carbon Dioxide on Broth Microdilution Susceptibility Testing of Brucella spp

et al. 2010

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Since some strains of Brucella species may require carbon dioxide for growth, a multilaboratory study was conducted to compare broth microdilution susceptibility results using ambient air (AA) and 5% CO 2 incubation conditions. Six antimicrobial agents were tested against 39 Brucella isolates. Aminoglycoside MICs tended to be 1 log 2 dilution higher in CO 2 than in AA; tetracycline-class MICs to be 1 log 2 dilution lower in CO 2 .Routine susceptibility testing of Brucella spp. is not recommended since the susceptibility pattern of wild-type Brucella spp. is fairly predictable, the isolates are fastidious, and the organisms are a potential cause of laboratory-acquired infection (3,12,17). In addition, Brucella spp. are intracellular pathogens, and like other intracellular pathogens, in vitro susceptibility may not always correlate with clinical outcome (1,3,28). Typically, brucellosis is treated with dual-antimicrobial therapy to lower the possibility of relapse. The most common combinations are streptomycin (or gentamicin) and doxycycline and doxycycline combined with rifampin (4, 12, 21, 28). Trimethoprim-sulfamethoxazole is recommended as alternative therapy (28), but use of fluoroquinolone therapy is controversial (12,18,25). Although there has been little or no resistance reported to routinely prescribed antimicrobials for brucellosis, relapse is still common (3,5,22,25), and development of laboratory-confirmed rifampin resistance has been reported (11).Brucella suis, Brucella melitensis, and Brucella abortus are considered potential agents of bioterrorism (6, 24). As with other potential bacterial agents of bioterrorism, engineered antimicrobial resistance is a concern. Antimicrobial susceptibility testing of Brucella spp. to identify effective therapeutic and prophylactic agents would be an important response effort in a bioterrorism event. Although no antibiotic regimen has been precisely studied for prophylaxis of brucellosis in humans, combining doxycycline and rifampin or using trimethoprimsulfamethoxazole alone (for children and pregnant women) has been used successfully in preventing laboratory-acquired disease, although side effects can occur (20,23,27).Many different methods of antimicrobial susceptibility testing, using a variety of media and incubation conditions, have been described for testing Brucella spp. (1, 3-5, 12-14, 16, 21, 22, 25, 26). Jevitt et al. (15) developed a standardized method for susceptibility testing of Brucella spp. using brucella broth, a method that was adopted by the Clinical and Laboratory Standards Institute (CLSI) in 2006 (9). This initial CLSI method for Brucella spp. described a broth microdilution (BMD) procedure using incubation at 35 Ϯ 2°C for 48 h in ambient air (AA). The present study describes a multicenter examination to evaluate incubation in ambient air supplemented with 5% CO 2 . Incubation in CO 2 -supplemented air is particularly important for some strains of Brucella spp. that are especially fastidious, such as B. abortus (19). Since many laboratories ...

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Relevance of in vitro antimicrobial susceptibility of Brucella melitensis to relapse rate in human brucellosis

Cited by 58 publications

References 27 publications

In vitro susceptibility of Brucella melitensis to antibiotics

In vitro susceptibility of Brucella melitensis to antibiotics

Implications of laboratory diagnosis on brucellosis therapy

Effect of Carbon Dioxide on Broth Microdilution Susceptibility Testing of Brucella spp

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