Antimicrobial potential of the Mayan medicine plant Matayba oppositifolia (A. Rich.) Britton against antibiotic-resistant priority pathogens.

ETHNOPHARMACOLOGICAL RELEVANCE: The bark of Matayba oppositifolia (A. Rich.) Britton (commonly known as "huaya" or "palo huacax") is commonly utilized in traditional Mayan medicine for treating diarrhea and for canker and other sores. AIM OF THE STUDY: The aim of this study was to investigate the in-vitro antimicrobial activity of M. oppositifolia bark extracts against drug-susceptible and -resistant ESKAPE-E pathogens. In addition, the phytochemical composition of the best antibacterial extract was analyzed. MATERIALS AND METHODS: The bark extracts were prepared with different solvents, including water, n-hexane, ethyl acetate and methanol. These were tested against ESKAPE-E (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp., including Escherichia coli) strains using Resazurin Microtiter Assay. In addition, the composition of the most active extract was analyzed by GC-MS. RESULTS: The aqueous and organic bark extracts showed activity on drug-susceptible and -resistant ESKAPE-E microbes (MIC = 1000-31.25 µg/mL). The n-hexane bark extract was more active against the superbugs carbapenem-resistant K. pneumoniae (MIC = 500-31.25 µg/mL) and A. baumannii (MIC = 250-125 µg/mL). The GC-MS analysis of this extract allowed the identification of 12 phytochemicals as the potential antibacterial compounds. The major compounds identified were palmitic acid (1), friedelan-3-one (2) and 7-dehydrodiosgenin (3). CONCLUSION: The present study reveals the strong in-vitro antibacterial activity of the n-hexane extract from the bark of M. oppositifolia and demonstrates the potential of natural products as a source of antibacterial compounds or phytomedicines that are specifically effective against drug-resistant ESKAPE-E bugs. Additionally, our investigation contributes to the ethnopharmacological knowledge and reappraisal of Mayan medicinal flora, as well as supports the traditional use of the bark of the medicinal plant M. oppositifolia for the treatment of infectious diseases.

Consumption of Maternal Placenta in Humans and Nonhuman Mammals: Beneficial and Adverse Effects.

Placentophagia is a common mammalian behavior, and the first scientific study of the potential effects of human maternal placentophagia on lactation was in 1917. More recently, in the 1970s, human placentophagia was reported in North America with a trend toward increased consumption. There are different hypotheses about the women and nonhuman mammals' motivation towards placentophagia, but few have been subject to hypotheses testing. In women, the controversy continues; on the one hand, researchers attribute benefits like increased breast milk, weight gain in newborns, decreased postpartum depression and fatigue, and improved mothers' mood. In contrast, bacterial or viral infections, hormonal, or trace elements that could become toxic for both the mother and baby are reported as possible health risks. Other reports argue a lack of scientific rigor to support the self-reported benefits of placentophagia. Also, the way the placenta is prepared (raw, cooked, dehydrated, processed, or encapsulated) alters its components, and thus the desired effects. This review provides relevant information and the different hypotheses and points of view around placentophagia. However, there are still questions to be resolved, and more studies are needed to confirm or reject the data generated so far about placentophagia in humans and nonhuman mammals.

Isolation and Histopathological Changes Associated with Non-Tuberculous Mycobacteria in Lymph Nodes Condemned at a Bovine Slaughterhouse.

Background: non-tuberculous mycobacteria (NTM) infect humans and animals and have a critical confounding effect on the diagnosis of bovine tuberculosis. The Official Mexican Standard (Norma Oficial Mexicana, NOM-ZOO-031-1995) for food safety regulates Mycobacterium bovis in cattle, but not the NTM species. The study's objective was to isolate and identify the NTM present in condemned bovine lymph nodes in a slaughterhouse, characterize the histological lesions, and correlate bacteriological and microscopic findings with the antemortem tuberculin skin test. Methods: from 528 cattle, one or two pooled samples of lymph nodes from each animal were cultured for Mycobacteria spp. and processed for histopathology. Results: mycobacteria were isolated from 54/528 (10.2%) of the condemned lymph nodes; 25/54 (46.2%) of these isolates were NTM; 4 bacteriological cultures with fungal contamination were discarded. Granulomatous and pyogranulomatous inflammation were present in 6/21 (28.6%) and 7/21 (33.3%) of the NTM-positive lymph nodes, respectively. The species of NTM associated with granulomatous lymphadenitis were M. scrofulaceum, M. triviale, M. terrae, and M. szulgai, while those causing pyogranulomatous lesions were M. szulgai, M. kansasii, M. phlei, and M. scrofulaceum. Conclusions: the NTM infections can cause false-positive results in the tuberculin test because of cross immune reactivity and interference with the postmortem identification of M. bovis in cattle.

In vitro growth inhibition and bactericidal activity of spathulenol against drug-resistant clinical isolates of Mycobacterium tuberculosis

ABSTRACT Spathulenol was isolated from an extract of Azorella compacta Phil., Apiaceae, by various chromatographic method; identification of the chemical structure was confirmed by comparing its spectroscopic data with those reported in the literature. The anti-Mycobacterium tuberculosis activity of spathulenol was evaluated on MDR, pre-XDR, and XDR clinical isolates of M. tuberculosis, as well as on the reference susceptible strain H37Rv and its cytotoxic activity was evaluated on the Vero Cell Line. The anti-M. tuberculosis activity of spathulenol was twice as potent against the MDR, pre-XDR, and XDR clinical isolates (6.25 µg/ml) than on the susceptible H37Rv strain (12.5 µg/ml). Additionally, the anti-M. tuberculosis activity shown by spathulenol was established as bactericidal on drug-resistant and susceptible strains of M. tuberculosis. Finally, cytotoxic activity on the Vero cell line (CC50 = 95.7 µg/ml) indicated that spathulenol is a selective anti-M. tuberculosis compound, with a selective index of 15.31 against drug-resistant clinical isolates of M. tuberculosis.

Use of a colorimetric assay to measure differences in cytotoxicity of Mycobacterium tuberculosis strains.

Several techniques have been used to quantify the cytotoxicity produced by Mycobacterium tuberculosis bacilli on cell monolayers; however, they are semi-quantitative or time consuming. Herein, a method based on crystal violet (CV) uptake by THP-1 cell monolayers is described. This colorimetric method quantifies the cytotoxic effect as a function of the number of remaining cells after the infection with M. tuberculosis. Since this micro-organism is not stained by the dye, it does not produce a background that affects absorbance readings. As determined by CV assay (CVA), M. tuberculosis strain H37Rv destroyed 10.5 % of THP-1 cell monolayers at 24 h and 50.52 % at 72 h, while M. tuberculosis strains lacking the complete phospholipase C locus produced a reduced cytotoxic effect. The damage estimated by microscopy corresponded to the effect quantified by CVA. The results show that the use of CVA is a rapid, sensitive and reliable quantitative assay to measure the cytotoxicity of different M. tuberculosis strains.

Genetic characterization of Mycobacterium tuberculosis clinical isolates with deletions in the plcA-plcB-plcC locus.

SETTING: The basis for Mycobacterium tuberculosis virulence is not completely understood. Analysis of the genomic structure of clinical isolates will give information that can be related to biological activities involved in virulence. OBJECTIVE: To determine the extension of the deletion in the plcA-plcB-plcC locus of selected M. tuberculosis isolates, as well as other changes in the chromosome. DESIGN: In the present work we characterized a group of M. tuberculosis isolates devoid of the plcA-plcB-plcC locus by PCR, sequencing and microarrays. RESULTS: PCR amplification of this region demonstrated a complete lack of plcA and plcB ORF's in all of the isolates. The plcC gene was completely deleted in one of the strains (DR-689) and the other three isolates still conserved part of this ORF. The loss of lateral DNA sequences ranged from 3723 to 7646bp. An IS6110 element was present in all tested strains cases, and some isolates presented the insertion of ORF's coding for proteins homologous to the ESAT-6 and QILSS families. Genomic DNA of all the strains was extracted and analyzed with an in-house microarray system to observe loss of other genes possibly implicated in attenuated virulence. Two of the strains presented novel deletions; the rest of the isolates showed deletions already reported for other M. tuberculosis strains. DR-689, a Beijing type M. tuberculosis strain isolated in Canada, showed an IS6110 RFLP and a genomic deletion pattern similar to a San Francisco family of strains, although completely unrelated epidemiologically. CONCLUSION: Genomic changes in M. tuberculosis seem to occur in a controlled manner and they are possibly related to changes in its pathogenic properties.