Adaptation of Brucella melitensis Antimicrobial Susceptibility Testing to the ISO 20776 Standard and Validation of the Method

Abstract

Brucellosis, mainly caused by Brucella (B.) melitensis, is associated with a risk of chronification and relapses. Antimicrobial susceptibility testing (AST) standards for B. melitensis are not available, and the agent is not yet listed in the EUCAST breakpoint tables. CLSI recommendations for B. melitensis exist, but they do not fulfill the requirements of the ISO 20776 standard regarding the culture medium and the incubation conditions. Under the third EU Health Programme, laboratories specializing in the diagnostics of highly pathogenic bacteria in their respective countries formed a working group within a Joint Action aiming to develop a suitable method for the AST of B. melitensis. Under the supervision of EUCAST representatives, this working group adapted the CLSI M45 document to the ISO 20776 standard after testing and validation. These adaptations included the comparison of various culture media, culture conditions and AST methods. A Standard Operation Procedure was derived and an interlaboratory validation was performed in order to evaluate the method. The results showed pros and cons for both of the two methods but also indicate that it is not necessary to abandon Mueller–Hinton without additives for the AST of B. melitensis.

Co-delivery of doxycycline and rifampicin using CdTe-labeled poly (lactic-co-glycolic) acid for treatment of Brucella melitensis infection

“…A chronic infection or disease relapse can be caused by bacteria residing in macrophages, which prevent cell death, adapt, grow, and evade the immune system [ 1 , 2 ]. Therefore, managing brucellosis necessitates extended antibiotic treatment to minimize the risk of recurrence and the development of chronic disease [ 3 , 4 ].…”

“…An effective treatment strategy requires a combination therapy due to the intracellular and slow-growth characteristics of B. melitensis , which incorporates at least one antimicrobial drug demonstrating robust penetration into intracellular spaces [ 3 , 7 ]. In challenging situations, exploring a treatment strategy that combines doxycycline with aminoglycosides such as gentamicin or streptomycin is recommended.…”

“…In challenging situations, exploring a treatment strategy that combines doxycycline with aminoglycosides such as gentamicin or streptomycin is recommended. Alternatively, doxycycline and rifampicin are other effective approaches, such as adding supplementary gentamicin [ 3 , 8 , 9 ]. Additional options include trimethoprim, sulfamethoxazole, fluoroquinolones, and ciprofloxacin [ 8 ].…”

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“…BMD ADT için CAMHB'un uygun olduğuna karar verilmiş ve BMD plaklarının doğru inokulumla hazırlanması ve %5 CO 2 ortam yerine normal ortamda 48 saat inkübe edilmesi gerektiği bildirilmiştir. Özellikle TMP-SMX MİK değerleri okunurken %80'lik üreme inhibisyonun dikkate alınması gerektiği vurgulanmıştır(57).Bruselloz, hücre içine yerleşebilen bir patojen olması nedeniyle, yinelemeleri ve kronikleşmeyi önlemek amacıyla uzun süreli ve kombinasyon tedavisi gerektirir. Kullanılacak ajanlardan birinin hücre içine geçişinin iyi olması önemlidir.…”