Determination of Susceptibility Rates of Nosocomial Acinetobacter baumannii Isolates to Sulbactam by E-test Method

Hastane infeksiyonlarına yol açan etkenler arasında Acinetobacter cinsi bakteriler önemli bir yer tutmaktadır. Çoklu ilaç dirençli Acinetobacter infeksiyonları dünyada artan oranlarda görülmektedir. Bu nedenle, terapötik seçenekler sınırlı hale gelmektedir. Duyarlılık oranları net olarak bilinmese de, tek başına sulbaktam veya sulbaktam-ampisilin, Acinetobacter infeksiyonlarının tedavisinde kombinasyonlarda yer almaktadır. Bu çalışmada, çoğul dirençli Acinetobacter baumannii kökenlerinde, sulbaktamın minimum inhibitör konsantrasyonu (MİK) değerleri E-test yöntemi ile incelenmiştir. Materyal ve Metod: Çalışmaya, 15 Haziran 2011-15 Haziran 2013 tarihleri arasında, Sağlık Bakanlığı Ankara Eğitim ve Araştırma Hastanesinde yatan hastalardan alınan klinik örneklerden izole edilen, karbapenem direncini de barındıran çoklu ilaca dirençli 100 A. baumannii kökeni alındı. Antibiyotik duyarlılıkları ve tür düzeyinde tanımlaması konvansiyonel yöntemler ve VITEK 2 (bioMérieux SA, Fransa) sistemi ile yapılmıştır. Üç veya daha fazla ilaç grubuna karşı direnç saptanması çoğul ilaç direnci olarak kabul edildi. Yüz izolat çalışma gününe kadar -80ºC'de gliserollü "brain heart" besiyerinde (Oxoid, UK) saklandı. Kontrol kökeni olarak Escherichia coli ATCC (American Type Culture Collection) 25922 kullanıldı. Sulbaktamın 100 izolata karşı E-test yöntemi ile saptanan MİK değerleri (µg/mL), MİK50 ve MİK90 değerleri (µg/mL) kaydedildi. Tek başına sulbaktamın Acinetobacter'e karşı belirlenmiş bir duyarlılık sınırı olmadığı için, duyarlılık oranları, literatürde rapor edilen MİK sınır değerleri dikkate alınarak hesaplanmıştır (<= 4 µg/mL ve <= 8 µg/mL). Bulgular: Acinetobacter izolatlarına karşı sulbaktam MİK değerleri geniş bir aralıkta dağılmıştı (1 µg/mL ile 256 µg/mL arasında); MİK50 ve MİK90 değerleri ise sırasıyla 12 µg/mL ve 96 µg/mL saptandı. Duyarlılık sınırı 8 µg/mL kabul edildiğinde, izolatların %44'ü duyarlı saptanmışken, sınır 4 µg/mL kabul edildiğinde bu oran %21 ile sınırlı kaldı. Sonuç: Çalışmamızdaki sulbaktam MİK değerleri göz önüne alındığında, çoklu ilaca dirençli A. baumannii tedavisinde sulbaktam umut verici bir ajan olarak görülmektedir. Ancak, özellikle klinik etkinlik konusunda farklı çalışmalara ihtiyaç vardır.Bacteria of the genus Acinetobacter play an important role as causative agents of hospital-acquired infections. Especially in recent years, multidrug-resistant Acinetobacter infections have increasingly been observed worldwide. In parallel with the increasing rate of infections, therapeutic options are becoming limited. Although the susceptibility rates are not exactly known, sulbactam alone or sulbactam with ampicillin play a part in combination therapies against Acinetobacter infections. This study aimed to determine the minimum inhibitory concentrations (MICs) of sulbactam against multidrug-resistant Acinetobacter baumannii strains using the E-test method and to deduce the susceptibility rates based on literature data.Materials and Methods: The study included 100 multidrug-resistant A. baumannii strains isolated from clinical samples obtained from patients hospitalized in intensive care units of the Ministry of Health Ankara Training and Research Hospital between June 15, 2011 and June 15, 2013. Antibiotic susceptibility testing and strain identification were performed using conventional methods and the VITEK 2 (bioM&eacute;rieux SA, France) system. Resistance to three or more drugs was considered as multidrug resistance. MIC, MICMIC values (&micro;g/mL) of sulbactam against the 100 isolates were determined using the E test method. Since the breakpoint MIC of sulbactam against Acinetobacter had not been established, the susceptibility rates were estimated based on the MIC values reported in the literature (&lt;= 4 or 8 &micro;g/mL).Results: The MIC values of sulbactam against the Acinetobacter isolates ranged widely (between 1 and 256 &micro;g/mL), and the MICand MIC values were determined to be 12 and 96 &micro;g/mL, respectively. When 8 &micro;g/mL was considered as the susceptibility breakpoint, 44% of the isolates were found to be susceptible; however, the rate was only 21% when 4 &micro;g/mL was considered as the breakpoint.Conclusion: Based on its MIC values determined in our study, sulbactam appeared to be a promising agent for the treatment of infections caused by multidrug-resistant A. baumannii isolates. Nonetheless, more studies are needed, especially on its clinical effectiveness

Determination of Susceptibility Rates of Nosocomial Acinetobacter baumannii Isolates to Sulbactam by E-test Method

WOS: 000458956900002Introduction: Bacteria of the genus Acinetobacter play an important role as causative agents of hospital-acquired infections. Multidrug-resistant Acinetobacter infections have increasingly been observed worldwide. In parallel with the increasing rate of infections, therapeutic options are becoming limited. Although the susceptibility rates are not exactly known, sulbactam alone or sulbactam with ampicillin play a part in combination therapies against Acinetobacter infections. This study aimed to determine the minimum inhibitory concentrations (MICs) of sulbactam against multidrug-resistant Acinetobacter baumannii strains using the E-test method and to deduce the susceptibility rates based on literature data. Materials and Methods: The study included 100 multidrug-resistant A. baumannii strains isolated from clinical samples obtained from patients hospitalized in intensive care units of the Ministry of Health Ankara Training and Research Hospital between June 15, 2011 and June 15, 2013. Antibiotic susceptibility testing and strain identification were performed using conventional methods and the VITEK 2 (bioMerieux SA, France) system. Resistance to three or more drugs was considered as multidrug resistance. MIC, MIC50, and MIC90 values (mu g/mL) of sulbactam against the 100 isolates were determined using the E test method. Since the breakpoint MIC of sulbactam against Acinetobacter had not been established, the susceptibility rates were estimated based on the MIC values reported in the literature (<= 4 or 8 mu g/mL). Results: The MIC values of sulbactam against the Acinetobacter isolates ranged widely (between 1 and 256 mu g/mL), and the MIC50 and MIC90 values were determined to be 12 and 96 mu g/mL, respectively. When 8 mu g/mL was considered as the susceptibility breakpoint, 44% of the isolates were found to be susceptible; however, the rate was only 21% when 4 mu g/mL was considered as the breakpoint. Conclusion: Based on its MIC values determined in our study, sulbactam appeared to be a promising agent for the treatment of infections caused by multidrug-resistant A. baumannii isolates. Nonetheless, more studies are needed, especially on its clinical effectiveness

Synergistic effects of sulbactam in multi-drug-resistant Acinetobacter baumannii

Abstract Acinetobacter baumannii is a frequently isolated etiologic agent of nosocomial infections, especially in intensive care units. With the increase in multi-drug resistance of A. baumannii isolates, finding appropriate treatment alternatives for infections caused by these bacteria has become more difficult, and available alternate treatments include the use of older antibiotics such as colistin or a combination of antibiotics. The current study aimed to evaluate the in vitro efficacy of various antibiotic combinations against multi-drug resistant A. baumannii strains. Thirty multi-drug and carbapenem resistant A. baumannii strains isolated at the Ankara Training and Research Hospital between June 2011 and June 2012 were used in the study. Antibiotic susceptibility tests and species-level identification were performed using conventional methods and the VITEK 2 system. The effects of meropenem, ciprofloxacin, amikacin, tigecycline, and colistin alone and in combination with sulbactam against the isolates were studied using Etest (bioMérieux) in Mueller-Hinton agar medium. Fractional inhibitory concentration index (FIC) was used to determine the efficacy of the various combinations. While all combinations showed a predominant indifferent effect, a synergistic effect was also observed in 4 of the 5 combinations. Synergy was demonstrated in 43% of the isolates with the meropenem-sulbactam combination, in 27% of the isolates with tigecycline-sulbactam, and in 17% of the isolates with colistin-sulbactam and amikacin-sulbactam. No synergy was detected with the sulbactam-ciprofloxacin combination and antagonism was detected only in the sulbactam-colistin combination (6.66% of the isolates). Antibiotic combinations can be used as an alternative treatment approach in multi-drug resistant A. baumannii infections

Determination of Susceptibility Rates of Nosocomial Acinetobacter baumannii Isolates to Sulbactam by E-test Method

Introduction: Bacteria of the genus Acinetobacter play an important role as causative agents of hospital-acquired infections. Multidrugresistant Acinetobacter infections have increasingly been observed worldwide. In parallel with the increasing rate of infections, therapeutic options are becoming limited. Although the susceptibility rates are not exactly known, sulbactam alone or sulbactam with ampicillin play a part in combination therapies against Acinetobacter infections. This study aimed to determine the minimum inhibitory concentrations (MICs) of sulbactam against multidrug-resistant Acinetobacter baumannii strains using the E-test method and to deduce the susceptibility rates based on literature data. Materials and Methods: The study included 100 multidrug-resistant A. baumannii strains isolated from clinical samples obtained from patients hospitalized in intensive care units of the Ministry of Health Ankara Training and Research Hospital between June 15, 2011 and June 15, 2013. Antibiotic susceptibility testing and strain identification were performed using conventional methods and the VITEK 2 (bioMérieux SA, France) system. Resistance to three or more drugs was considered as multidrug resistance. MIC, MIC50, and MIC90 values (µg/mL) of sulbactam against the 100 isolates were determined using the E test method. Since the breakpoint MIC of sulbactam against Acinetobacter had not been established, the susceptibility rates were estimated based on the MIC values reported in the literature (≤ 4 or 8 µg/mL). Results: The MIC values of sulbactam against the Acinetobacter isolates ranged widely (between 1 and 256 µg/mL), and the MIC50 and MIC90 values were determined to be 12 and 96 µg/mL, respectively. When 8 µg/mL was considered as the susceptibility breakpoint, 44% of the isolates were found to be susceptible; however, the rate was only 21% when 4 µg/mL was considered as the breakpoint. Conclusion: Based on its MIC values determined in our study, sulbactam appeared to be a promising agent for the treatment of infections caused by multidrug-resistant A. baumannii isolates. Nonetheless, more studies are needed, especially on its clinical effectiveness

The Relationship between COVID-19 Severity and Bacillus Calmette-Guerin (BCG)/ Mycobacterium tuberculosis exposure history in healthcare workers: a multi-center study

The COVID-19 pandemic has brought countries' health services into sharp focus. It was drawn to our group's attention that healthcare workers (HCWs) had a lower mortality rate against higher COVID-19 incidence compared to the general population in Turkey. Since risk of exposure to tuberculosis bacillus among healthcare workers are higher than the population, we aimed to investigate if there is a relationship between BCG and Mycobacterium tuberculosis exposure history with COVID-19 severity in infected HCWs. This study was conducted with 465 infected HCWs from thirty-three hospitals to assess the relationship between COVID-19 severity (according to their hospitalization status and the presence of radiological pneumonia) and BCG and Mycobacterium tuberculosis exposure history. HCWs who required hospital admission had significantly higher rates of chronic diseases, radiological pneumonia, and longer working hours in the clinics. Higher rates of history of contact and care to tuberculosis patients, history of tuberculosis, and BCG vaccine were observed in hospitalized HCWs. HCWs who had radiological pneumonia had a significantly increased ratio of history of care to tuberculosis patients and a higher family history of tuberculosis. The findings from our study suggest that the lower mortality rate despite the more severe disease course seen in infected HCWs might be due to frequent exposure to tuberculosis bacillus and the mortality-reducing effects of the BCG vaccine