First nosocomial outbreak of SME-4-producing Serratia marcescens in South America / Primer brote nosocomial por Serratia marcescens productora de SME-4en Sudamérica

Abstract Carbapenemase-producing-Serratia marcescens isolates, although infrequent, are considered important nosocomial pathogens due to their intrinsic resistance to polymyxins, which limits therapeutic options. We describe a nosocomial outbreak of SME-4-producing S. marcescens in Buenos Aires city which, in our knowledge, represents the first one in South America.

Resumen Los aislamientos de origen nosocomial de Serratia marcescens productores de car-bapenemasa, si bien son infrecuentes, son considerados importantes patógenos debido a su resistencia intrínseca a las polimixinas, lo cual limita aún más las opciones terapéuticas. En este trabajo se describe un brote nosocomial causado por S. marcescens portadora de car-bapenemasa de tipo SME-4 en la Ciudad de Buenos Aires, el cual representaría el primero en Sudamérica.

First nosocomial outbreak of SME-4-producing Serratia marcescens in South America.

Carbapenemase-producing-Serratia marcescens isolates, although infrequent, are considered important nosocomial pathogens due to their intrinsic resistance to polymyxins, which limits therapeutic options. We describe a nosocomial outbreak of SME-4-producing S. marcescens in Buenos Aires city which, in our knowledge, represents the first one in South America.

In vitro synergistic activity of aztreonam (AZT) plus novel and old ß-lactamase inhibitor combinations against metallo-ß-lactamase-producing AZT-resistant Enterobacterales.

The emergence of metallo-ß-lactamase (MBL)-producing Enterobacterales, mainly New Delhi metallo-ß-lactamase (NDM), represents a clinical threat due to the limited therapeutic alternatives. Aztreonam (AZT) is stable to MBLs, but most MBL-producing Enterobacterales isolates usually co-harbour other ß-lactamases that confer resistance to AZT and, consequently, its use is restricted in these isolates. We compared the ability of sulbactam (SUL), tazobactam (TAZ), clavulanic acid (CLA) and avibactam (AVI) to restore the AZT activity in MBL-producing AZT-resistant Enterobacterales isolates. A collection of 64 NDM-producing AZT-resistant Enterobacterales from five hospitals in Buenos Aires city, Argentina, were studied during the period July-December 2020. MICs were determined using the agar dilution method with Mueller-Hinton agar according to Clinical and Laboratory Standards Institute (CLSI) recommendations. AVI, SUL and TAZ were used at a fixed concentration of 4 mg l-1, whereas CLA was used at a fixed concentration of 2 mg l-1. A screening method based on disc diffusion to evaluate this synergy was also conducted. Detection of bla KPC, bla OXA, bla NDM, bla VIM, bla CTXM-1, bla PER-2 and bla CIT was performed by PCR. The AZT-AVI combination restored the AZT activity in 98.4 % of AZT-resistant strains, whereas CLA, TAZ and SUL did so in 70.3, 15.6 and 12.5 %, respectively, in isolates co-harbouring extended-spectrum ß-lactamases, but were inactive in isolates harbouring AmpC-type enzymes and/or KPC. The synergy screening test showed an excellent negative predictive value to confirm the absence of synergy, but positive results should be confirmed by a quantitative method. The excellent in vitro performance of the AZT-CLA combination represents a much more economical alternative to AZT-AVI, which could be of use in the treatment of MBL-producing, AZT-resistant Enterobacterales.

Analgesia en cirugía torácica (toracotomía) / Analgesia in thoracic surgery (thoracotomy)

Resumen: La cirugía torácica abierta se encuentra entre las cirugías más dolorosas y sus resultados se ven afectados adversamente por el malestar postoperatorio. La analgesia óptima en toracotomía, la disminución en el consumo de narcóticos, un despertar rápido y predecible, la prevención de efectos adversos, la movilización temprana y maniobras de fisioterapia respiratoria, así como el uso seguro de fármacos en recuperación y piso, son las estrategias más importantes para un manejo óptimo perioperatorio. Hasta hace unos años, la analgesia epidural era considerada el estándar analgésico; sin embargo, intervenciones como el bloqueo paravertebral también han sido evaluadas. El síndrome de dolor postoracotomía (PTPS) es una complicación bien reconocida, su incidencia varía entre el 15 y 67% de acuerdo con la definición. Se realizó la búsqueda en diversas fuentes de literatura para poder emitir recomendaciones perioperatorias, con mayor evidencia, esto se realizó con un equipo multidisciplinario para la emisión del manejo multimodal del dolor (visita http://www.painoutmexico.com para obtener la versión completa del artículo y el diagrama de recomendaciones).

Abstract: Open thoracic surgery is among the most painful surgeries and its results are adversely affected by postoperative discomfort. The optimal analgesia in thoracotomy, the decrease in the consumption of narcotics, a rapid and predictable awakening, the prevention of adverse effects, the early mobilization and maneuvers of respiratory physiotherapy, as well as the safe use of drugs, are the most important strategies for optimal perioperative management. Until a few years ago, epidural analgesia was considered the gold standard, however, interventions such as paravertebral block have been evaluated as well. Post-thoracotomy pain syndrome (PTPS) is a well-recognized complication, its incidence varies between 15 and 67% according to the definition. This review includes recommendations of literature sources to be able to translate perioperative recommendations with the highest evidence level, this was done including a multidisciplinary team for the issuance of multimodal pain management (visit http://www.painoutmexico.com to see the full article and recommendations diagram).

Essential oil of Galinsoga parviflora leaves from Colombia.

The chemical composition of the volatile compounds from the leaves of Galinsoga parviflora Cav. (Asteraceae) from Colombia was studied by GC and GC/MS. Eighty-eight volatile compounds were identified, of which the major ones were (Z)-3-hexen-1-ol (21.7%), beta-caryophyllene (12.4%), and 6-demethoxy-ageratochrome (14%). The leaf oil presented antimicrobial activities against the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus.

Efecto de la vitamina E, DL alfa-tocoferol, sobre el daño cromosómico en linfocitos de pacientes con ataxia telangiectasia / Effect of vitamin E, DL alfa-tocopherol, on chromosomal damage in lymphocytes from patients with ataxia telangiectasia

Background: In ataxia telangiectasia (A-T), the lack of a functional ATM kinase is associated with disturbances in the processing of DNA damage and a chronic oxidative stress. These disturbances may be responsible for an increment of chromosomal damage in A-T cells. Aim: To study the in vitro effect of vitamin E (DL-a-tocopherol) on the frequency of chromosomal damage of lymphocytes from patients with A-T. Patients and methods: Seven patients with A-T and age-sex matched controls were studied. Chromosomal damage in mitosis was evaluated in lymphocytes cultures both under basal conditions and when G2 repair was prevented by 5 mM caffeine. Results: In cells from patients with A-T, vitamin E induced a 57.1 and 47.9 percent decrease in chromosomal damage under basal and inhibited G2 repair conditions, respectively. However, there was a non significant improvement in their repair activity. Vitamin E effects on chromosomal damage was not significant in control subjects. Conclusions: Vitamin E reduces chromosomal damage in lymphocytes from patients with ataxia telangiectasia