[Antibiotic susceptibility of Staphylococcus aureus and Streptococcus pneumoniae in healthy carrier individuals in primary care in Barcelona area]

Biological Activities of Seven Medicinal Plants Used in Chiapas, Mexico

Seven medicinal plants from Chiapas, Mexico, used by Native Americans were analyzed, aiming to improve the understanding of their medicinal properties through the evaluation of various biological activities, i.e., bactericidal, antioxidant, α-glucosidase inhibition, and toxicity, to provide a scientific basis for the management of infectious and hyperglycemic diseases in the Mexican southeast. Plant extracts were obtained from Cordia dodecandra, Gaultheria odorata, Heliotropium angiospermum, Justicia spicigera, Leucaena collinsii spp. collinsii, Tagetes nelsonii, and Talisia oliviformis through maceration techniques using methanol and chloroform (1:1). Minimum Inhibitory Concentration (MIC) was employed to determine the antibacterial activity against Staphylococcus aureus, Enterobacter faecalis, Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeuroginosa. The antiradical/antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays and antihemolytic activity using the 2,2’-Azobis(2-amidinopropane) dihydrochloride radical (APPH). The anti-α-glucosidase activity was evaluated in vitro through the chromogenic PNPG assay. The toxicity was assessed using the brine shrimp lethality assay. The highest antimicrobial activity was displayed by T. nelsonii, mainly against E. faecalis and P. aeuroginosa. The extracts of L. collinsii, J. spicigera, and T. nelsonii possess antioxidant properties with EC50 < 50 μg/mL. J. spicigera and T. nelsonii extracts showed the highest antihemolytic activity with IC50 < 14 μg/mL. T. nelsonii exhibited a remarkable inhibitor effect on the α-glucosidase enzyme and the greatest toxic effect on Artemia salina with IC50 = 193 ± 20 μg/mL and LD50 = 14 ± 1 μg/mL, respectively. According to our results, G. odorata, J. spicigera, T. nelsonii, and T. oliviformis extracts contained active antimicrobial compounds. At the same time, T. nelsonii stands to be a possible source of effective antineoplastic and antihyperglycemic compounds.

Antibacterial Effect of Luma apiculata (DC.) Burret Extracts in Clinically Important Bacteria

Nosocomial infections caused by bacteria are one of the main public health problems. Moreover, the resistance to antibiotics by these bacteria makes it necessary to find new treatments to fight them. Objective. To evaluate the antibacterial activity of Luma apiculata (DC.) Burret extracts on bacteria of clinical importance. Materials and Methods. In this study, extracts were obtained at room temperature by successive extraction of L. apiculata leaves, flowers, and branches and treated separately with solvents of ascending polarity (i.e., hexane, methylene dichloride, ethyl acetate, ethanol, methanol, and water) to extract the compounds depending on their polarity. Then, the extract's antibacterial activity was tested against Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Enterococcus sp, Acinetobacter baumanii, Pseudomonas aeruginosa, and Escherichia coli. Results. The hexane extract of L. apiculata leaves resulted to be active against all bacteria tested. Among them, S. aureus showed to be the more susceptible, showing a minimum inhibitory concentration (MIC) of 120 μg/ml. In addition, a growth curve was performed, and colonies were counted. A decrease in bacterial growth was observed when the hexane extract of L. apiculata leaves was added. Besides, the hexane extracts of L. apiculata flowers resulted to be active against all Gram-positive tested bacteria. However, at higher concentrations, this extract resulted inactive for the Gram-negative bacteria tested. The hexane extract of L. apiculata branches resulted to be inactive in all cases. The extracts obtained treating separately leaves, flowers, or branches with solvents of major polarity than the hexane in a successive extraction of ascending polarity methodology resulted also to be inactive as an antimicrobial against all bacteria tested. Discussion/Conclusion. The hexane extract of L. apiculata leaves showed the lower MIC against S. aureus when compared with extracts obtained from other parts of the plant. The growth curve and the colonies count suggest a bacteriostatic activity of the L. apiculata leaves extract against Staphylococcus aureus.

Previous antibiotic exposure and antibiotic resistance of commensal Staphylococcus aureus in Spanish primary care

INTRODUCTION

Commensal flora of healthy people is becoming an important reservoir of resistant bacteria.

OBJECTIVES

To evaluate the relationship of previous antibiotic-dispensed and resistance pattern of strains of Staphylococcus aureus in primary care patients.

METHODS

A cross-sectional study was carried out in seven primary care centres in Catalonia, Spain, from October 2010 to May 2011, as part of the APRES (The appropriateness of prescribing antibiotics in primary care in Europe concerning antibiotic resistance) study. Outpatients aged 4 or more who did not present an infectious disease and had not taken antibiotic or had not been hospitalised in the previous 3 months were invited to participate. Nasal swabs were collected for S. aureus culture, and antimicrobial susceptibility testing was carried out. Antibiotics dispensed boxes in the previous 4 years were extracted from Information System for Research in Primary Care.

RESULTS

A total of 4,001 nasal swabs were collected, and 3,969 were tested for identification, 765 S. aureus were tested for resistance. Resistance rates to penicillin, azithromycin and methicillin were 87.1%, 11.6% and 1.3%, respectively, and a total of 10 MRSA strains were isolated (1.3%). Penicillin-resistant staphylococci were statistically significantly associated with the previous number of packages of penicillin dispensed (OR, 1.18; 95% CI, 1.04-1.35).

CONCLUSION

Although no causal inference is possible, an association was observed between previous antibiotic dispensation and isolation of resistant organisms in community-dwelling individuals, mainly between packages of penicillin and penicillin-resistant staphylococci.