Aims:  To evaluate the antibacterial and free‐radical scavenging (FRS) activities of propolis collected from three different areas of Sonoran Desert in northwestern Mexico [Pueblo de Alamos (PAP), Ures (UP) and Caborca (CP)]. Methods and Results:  The antibacterial and FRS activities of Sonoran propolis were determined by the broth microdilution method and the DPPH (1,1‐diphenyl‐2‐picrylhydracyl) assay, respectively. Propolis samples had antibacterial activity against only Gram‐positive bacteria. The UP sample showed the highest antibacterial activity against Staphylococcus aureus [minimal inhibitory concentration (MIC) 100 μg ml−1] in a concentration‐dependent manner (UP > CP > PAP). Caffeic acid phenethyl ester (CAPE), a UP propolis constituent, had very high growth‐inhibitory activity towards Gram‐positive bacteria, particularly against S. aureus (MIC 0·1 mmol l−1). To our knowledge, this is the first study showing a strong antibacterial activity of CAPE against S. aureus. Additionally, propolis CP exhibited high FRS activity (86% ± 0·3 at 100 μg ml−1) comparable with those of the reference antioxidants vitamin C (87·4% ± 1·7 at 70 μmol l−1) and BHT (66·07% ± 0·76 at 140 μmol l−1). The propolis compounds CAPE and rutin showed high FRS activity (90·4% ± 0·2 and 88·5% ± 0·8 at 70 μmol l−1, respectively). Conclusions:  Sonoran propolis UP and CAPE had strong antibacterial activity against S. aureus. In addition, propolis CP showed potent FRS activity comparable with those of vitamin C and BHT. Significance and Impact of the study:  The strong antibacterial and antioxidant properties of Sonoran propolis and some of its constituents support further studies on the clinical applications of this natural bee product against S. aureus and several oxidative damage‐related diseases.

The cellular immune response plays a critical role in the containment of persistent Mycobacterium tuberculosis infection; however, the immunological mechanisms that lead to its control are not completely identified. The goal of this study was to evaluate B (CD19+) and T (CD3+) peripheral blood lymphocyte profiles and T-cell subsets (CD4+ and CD8+) in patients with pulmonary tuberculosis (TB). Percentages (p = 0.02) and absolute numbers (p = 0.005) of B cells were significantly lower in patients with pulmonary TB than in healthy donors. In contrast, percentages (p = 0.12) and absolute numbers (p = 0.14) of T cells were similar in TB patients and healthy donors. No significant differences in percentages of CD4+ (p = 0.19) or CD8+ (p = 0.85) T cells between patients and healthy donors were observed. In summary, patients with pulmonary tuberculosis had a lower number of peripheral blood B lymphocytes than healthy controls.

The clinical and bacteriological response of 38 treatments performed on 24 children (11 of them neonates) carrying out separate treatments with carbenicillin (2 treatments), gentamicin [4], fosfomycin [6], and associated treatments with gentamicin plus carbenicillin [6], fosfomycin plus gentamicin [18] and fosfomycin plus carbenicillin [2] are considered. The clinical cure was obtained in 21 children (87.5%). The most effective treatment was fosfomycin plus gentamicin; both antibiotics showed synergism in vitro on isolated Serratia strains. A dosage of 75 mg/kg fosfomycin enables serum levels of about 32 μg/ml during 4–5 h, being this level higher to the MIC of all isolated strains of S. marcescens.

Campylobacter coli strain 981 of animal origin was resistant to erythromycin, tetracycline, streptomycin, kanamycin, ribostamycin, neomycin, paromomycin, lividomycin, and butirosin. Resistance to aminoglycosides of strain 981 was mediated by phosphotransferases APH (3') type-IV and APH (3"). C. coli 981 harboured three plasmids of 24, 34, and 40 Megadaltons respectively. None of these plasmids were transferable to Escherichia coli K-12 by conjugation.

This study shows the seasonal effect on the antioxidant, antiproliferative, and antimicrobial activities of L. glaucescens Kunth (LG) leaves extracts. Their antioxidant activity was evaluated through the DPPH, FRAP, and ORAC assays. Their phenolic content (PC) was determined by means of the Folin-Ciocalteu method, and the main phenolic compounds were identified through a HPLC-DAD analysis. Antiproliferative activity was determined by MTT assay against HeLa, LS 180, M12.C3.F6, and ARPE cell lines. Antimicrobial potential was evaluated against Staphylococcus aureus and Escherichia coli using a microdilution method. All the LG extracts presented high antioxidant activity and PC, with quercitrin and epicatechin being the most abundant. Antioxidant activity and PC were affected by the season; particularly autumn (ALGE) and summer (SULGE) extracts exhibited the highest values (p < 0.05). All extracts presented moderate antiproliferative activity against the cell lines evaluated, HeLa being the most susceptible of them. However, ALGE and SULGE were the most active too. About antimicrobial activity, SULGE (MIC90 < 800 μg/mL; MIC50 < 400 μg/mL), and SLGE (MIC50 < 1000 μg/mL) showed a moderate inhibitory effect against S. aureus. These findings provide new information about the seasonal effect on the PC and biological properties of LG extracts. Clearly, antioxidant activity was the most important with respect to the other two.

Este libro detalla los procedimientos más comunes que se realizan en el laboratorio de bacteriología médica. También explica la importancia e impacto clínico de cada procedimiento. Para programas educativos en el área de las Ciencias de la Salud.