Anti-Omp34 antibodies protect against Acinetobacter baumannii in a murine sepsis model

The stimulation of the immune response to prevent the progression of an infection may be an adjuvant to antimicrobial treatment. Here, we aimed to evaluate the efficacy of lysophosphatidylcholine (LPC) treatment in combination with colistin in murine experimental models of severe infections by Acinetobacter baumannii. We used the A. baumannii Ab9 strain, susceptible to colistin and most of the antibiotics used in clinical settings, and the A. baumannii Ab186 strain, susceptible to colistin but presenting a multidrug-resistant (MDR) pattern. The therapeutic efficacies of one and two LPC doses (25 mg/kg/d) and colistin (20 mg/kg/8 h), alone or in combination, were assessed against Ab9 and Ab186 in murine peritoneal sepsis and pneumonia models. One and two LPC doses combined with colistin and colistin monotherapy enhanced Ab9 and Ab186 clearance from spleen, lungs and blood and reduced mice mortality compared with those of the non-treated mice group in both experimental models. Moreover, one and two LPC doses reduced the bacterial concentration in tissues and blood in both models and increased mice survival in the peritoneal sepsis model for both strains compared with those of the colistin monotherapy group. LPC used as an adjuvant of colistin treatment may be helpful to reduce the severity and the resolution of the MDR A. baumannii infection.

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Protective response against Acinetobacter baumannii with ferric iron receptors HemTR-BauA in a murine sepsis model

Future Microbiology ◽

10.2217/fmb-2020-0133 ◽

2021 ◽

Vol 16 (3) ◽

pp. 143-157

Author(s):

Fatemeh Ramezanalizadeh ◽

Iraj Rasooli ◽

Parviz Owlia

Keyword(s):

Acinetobacter Baumannii ◽

Iron Uptake ◽

Ferric Iron ◽

Vaccine Development ◽

Passive Transfer ◽

Internal Organs ◽

Protective Response ◽

Sepsis Model ◽

High Level ◽

Uptake And Metabolism

Aim: Iron uptake and metabolism pathways are promising targets in vaccine development as an alternative strategy for antibiotics. Methods & methods: HemTR, a putative heme receptor of Acinetobacter baumannii, was expressed and its protectivity against A. baumannii was determined singly or in combination with the siderophore receptor, BauA, in mice. Results: High level of IgG was elicited. There was a delay in mice mortality with reduced bacterial loads in internal organs in the sublethal challenge. Protection was better in the HemTR-BauA group in both lethal and sublethal challenges. Passive transfer of anti-HemTR and anti-BauA partially protected mice against A. baumannii infection. Conclusion: HemTR in combination with other iron receptors could contribute to the development of protective vaccines against A. baumannii.

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Effects of Colistin Sulphate, Tigecycline, and Cefoperazone-Sulbactam on the Multi-Drug Resistant Acinetobacter baumannii Experimental Mouse Sepsis Model

Çocuk Enfeksiyon Dergisi/Journal of Pediatric Infection ◽

10.5152/ced.2015.1957 ◽

2015 ◽

Vol 9 (1) ◽

pp. 25-33

Author(s):

Emre Temur ◽

Ener Çağrı Dinleyici ◽

Rahmi Tuna Tekin ◽

Abdurrahman Kiremitçi ◽

Başar Sırmagül ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Drug Resistant ◽

Sepsis Model ◽

Experimental Mouse ◽

Mouse Sepsis Model

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Colistin Resistance in a Clinical Acinetobacter baumannii Strain Appearing after Colistin Treatment: Effect on Virulence and Bacterial Fitness

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00543-13 ◽

2013 ◽

Vol 57 (9) ◽

pp. 4587-4589 ◽

Cited By ~ 58

Author(s):

Rafael López-Rojas ◽

Michael J. McConnell ◽

Manuel Enrique Jiménez-Mejías ◽

Juan Domínguez-Herrera ◽

Felipe Fernández-Cuenca ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Treatment Effect ◽

Competition Index ◽

Colistin Resistance ◽

Content Type ◽

Time To Death ◽

Sepsis Model ◽

Bacterial Fitness

ABSTRACTThe fitness and virulence costs associated with the clinical acquisition of colistin resistance byAcinetobacter baumanniiwere evaluated. The growth of strain CR17 (colistin resistant) was less than that of strain CS01 (colistin susceptible) when the strains were grown in competition (72-h competition index, 0.008). In a murine sepsis model, CS01 and CR17 reached spleen concentrations when coinfecting of 9.31 and 6.97 log10CFU/g, respectively, with anin vivocompetition index of 0.016. Moreover, CS01 was more virulent than CR17 with respect to mortality and time to death.

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Efficacy of lysophosphatidylcholine as direct treatment in combination with colistin against Acinetobacter baumannii in murine severe infections models

10.1101/2020.12.02.409243 ◽

2020 ◽

Author(s):

A Miró-Canturri ◽

R Ayerbe-Algaba ◽

ME Jiménez-Mejías ◽

J Pachón ◽

Y Smani

Keyword(s):

Acinetobacter Baumannii ◽

Experimental Models ◽

Antimicrobial Treatment ◽

Clinical Settings ◽

Bacterial Clearance ◽

Bacterial Concentration ◽

Direct Treatment ◽

Sepsis Model ◽

Severe Infections ◽

Stimulation Of

ABSTRACTObjectivesThe stimulation of the immune response to prevent the progression of the infection may be an adjuvant to antimicrobial treatment. Previously, we showed that preemptive treatment with lysophosphatidylcholine (LPC) in combination with colistin improved the therapeutic efficacy of colistin against MDR Acinetobacter baumannii. In this study, we aimed to evaluate the efficacy of direct treatment with LPC in combination with colistin in murine experimental models of severe infections by A. baumannii.MethodsWe used A. baumannii strain Ab9, which is susceptible to colistin and most of the antibiotics used in clinical settings, and A. baumannii strain Ab186, which is susceptible to colistin but presents a MDR pattern. The therapeutic efficacies of one and two doses of LPC (25 mg/kg/d) and colistin (20 mg/kg/8h), alone or in combination, were assessed against Ab9 and Ab186 in murine peritoneal sepsis and pneumonia models.ResultsOne and two doses of LPC in combination with colistin and colistin monotherapy enhanced bacterial clearance of Ab9 and Ab186 from spleen, lungs and blood and reduced mortality rates compared with those of the non-treated mice group in both experimental models (P<0.05). Moreover, one and two doses of LPC reduced the bacterial concentration in tissues and blood in both models, and increased mice survival in peritoneal sepsis model for both strains compared with those of colistin monotherapy group.ConclusionsLPC used as an adjuvant of colistin treatment may be helpful to reduce the severity and the resolution of the infection by MDR A. baumannii.

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Efficacy of dual carbapenem treatment in a murine sepsis model of infection due to carbapenemase-producing Acinetobacter baumannii

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkaa487 ◽

2020 ◽

Author(s):

T Cebrero-Cangueiro ◽

P Nordmann ◽

M Carretero-Ledesma ◽

J Pachón ◽

M E Pachón-Ibáñez

Keyword(s):

Acinetobacter Baumannii ◽

Experimental Model ◽

Bacterial Load ◽

In Vivo Efficacy ◽

Female Mice ◽

Carbapenem Resistant ◽

Sepsis Model ◽

Lethal Doses ◽

Better Than

Abstract Objectives To evaluate the in vivo efficacy of a dual carbapenem combination containing imipenem plus meropenem against carbapenem-resistant Acinetobacter baumannii producing carbapenemases OXA-23 or OXA-58. Methods An experimental model of peritonitis using C57BL/6J female mice was developed and the minimum lethal doses were calculated for infections due to OXA-23 or OXA-58 producers of A. baumannii clinical isolates. The efficacies of the carbapenems in monotherapy and in combination were tested. Results Meropenem was better than imipenem in mice infected with either of the carbapenem-resistant A. baumannii (CRAb) strains. The combination of meropenem plus imipenem significantly improved the clearance of CRAbs from spleen compared with non-treated groups. The carbapenem-containing combination was better than imipenem for treating mice infected with both carbapenemase producers. In blood, the carbapenem combination significantly decreased the bacterial load of the OXA-23 producers compared with imipenem or meropenem used in monotherapy. Conclusions These results suggest that dual carbapenem combination could be an option for the treatment of infections due to carbapenemase-producing A. baumannii such as OXA-23 and OXA-58 producers.

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