The Outer Membrane Vesicles of Aeromonas hydrophila ATCC® 7966TM: A Proteomic Analysis and Effect on Host Cells

Gram-negative bacteria release outer membrane vesicles (OMVs) into the extracellular environment. OMVs have been studied extensively in bacterial pathogens, however, information related with the composition of Aeromonas hydrophila OMVs is missing. In this study we analyzed the composition of purified OMVs from A. hydrophila ATCC® 7966TM by proteomics. Also we studied the effect of OMVs on human peripheral blood mononuclear cells (PBMCs). Vesicles were grown in agar plates and then purified through ultracentrifugation steps. Purified vesicles showed an average diameter of 90–170 nm. Moreover, 211 unique proteins were found in OMVs from A. hydrophila; some of them are well-known as virulence factors such as: haemolysin Ahh1, RtxA toxin, extracellular lipase, HcpA protein, among others. OMVs from A. hydrophila ATCC® 7966TM induced lymphocyte activation and apoptosis in monocytes, as well as over-expression of pro-inflammatory cytokines. This work contributed to the knowledge of the composition of the vesicles of A. hydrophila ATCC® 7966TM and their interaction with the host cell

Aislamiento e identificación de Aeromonas bestiarum a partir de carpa común de cultivo (Cyprinus carpio L.) procedentes de Santa María Chapa de Mota, Estado de México, México

The isolation of Aeromonas bestiarum from common carps (Cyprinus carpio L.), cultivated at Santa Maria Chapa de Mota, is reported for the first time. The genetic identification for differentiating A. bestiarum from A. salmonicida is here emphasized

Serogroups, K1 antigen, and antimicrobial resistance patterns of Aeromonas spp. strains isolated from different sources in Mexico

A total of 221 strains of Aeromonas species isolated in Mexico from clinical (161), environmental (40), and food (20) samples were identified using the automated system bioMérieux-Vitek®. Antisera for serogroups O1 to 044 were tested using the Shimada and Sakazaki scheme. The K1 antigen was examined using as antiserum the O7:K1C of Escherichia coli . Besides, we studied the antimicrobial patterns according to Vitek AutoMicrobic system. Among the 161 clinical strains 60% were identified as A. hydrophila, 20.4% as A. caviae, and 19.25% as A. veronii biovar sobria. Only A. hydrophila and A. veronii biovar sobria were found in food (55 and 90% respectively) and environmental sources (45 and 10% respectively). Using "O" antisera, only 42.5% (94/221) of the strains were serologically identified, 55% (121/221) were non-typable, and 2.5% (6/221) were rough strains. Twenty-two different serogroups were found, O14, O16, O19, O22, and O34 represented 60% of the serotyped strains. More than 50% of Aeromonas strain examined (112/221) expressed K1 encapsulating antigen; this characteristic was predominant among Aeromonas strains of clinical origin. Resistance to ampicillin/sulbactam and cephazolin was detected in 100 and 67% of Aeromonas strain tested for their susceptibility to antibiotics. In conclusion, antibiotic-resistant Aeromonas species that possess the K1 encapsulating antigen and represent serogroups associated with clinical syndrome in man are not uncommon among Aeromonas strains isolated from clinical, food and environmental sources in Mexico

Anti-Mycobacterium tuberculosis Activity of Esters of Quinoxaline 1,4-Di-N-Oxide

Tuberculosis continues to be a public health problem in the world, and drug resistance has been a major obstacle in its treatment. Quinoxaline 1,4-di-N-oxide has been proposed as a scaffold to design new drugs to combat this disease. To examine the efficacy of this compound, this study evaluates methyl, ethyl, isopropyl, and n-propyl esters of quinoxaline 1,4-di-N-oxide derivatives in vitro against Mycobacterium tuberculosis (pansusceptible and monoresistant strains). Additionally, the inhibitory effect of esters of quinoxaline 1,4-di-N-oxide on M. tuberculosis gyrase supercoiling was examined, and a stability analysis by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS) was also carried out. Results showed that eight compounds (T-007, T-018, T-011, T-069, T-070, T-072, T-085 and T-088) had an activity similar to that of the reference drug isoniazid (minimum inhibitory concentration (MIC) = 0.12 µg/mL) with an effect on nonreplicative cells and drug monoresistant strains. Structural activity relationship analysis showed that the steric effect of an ester group at 7-position is key to enhancing its biological effects. Additionally, T-069 showed a high stability after 24 h in human plasma at 37 °C

Anti-mycobacterium tuberculosis activity of esters of quinoxaline 1,4-Di-N-Oxide

Tuberculosis continues to be a public health problem in the world, and drug resistance has been a major obstacle in its treatment. Quinoxaline 1,4-di-N-oxide has been proposed as a scaffold to design new drugs to combat this disease. To examine the efficacy of this compound, this study evaluates methyl, ethyl, isopropyl, and n-propyl esters of quinoxaline 1,4-di-N-oxide derivatives in vitro against Mycobacterium tuberculosis (pansusceptible and monoresistant strains). Additionally, the inhibitory effect of esters of quinoxaline 1,4-di-N-oxide on M. tuberculosis gyrase supercoiling was examined, and a stability analysis by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS) was also carried out. Results showed that eight compounds (T-007, T-018, T-011, T-069, T-070, T-072, T-085 and T-088) had an activity similar to that of the reference drug isoniazid (minimum inhibitory concentration (MIC) = 0.12 µg/mL) with an effect on nonreplicative cells and drug monoresistant strains. Structural activity relationship analysis showed that the steric effect of an ester group at 7-position is key to enhancing its biological effects. Additionally, T-069 showed a high stability after 24 h in human plasma at 37 ◦C