Practical Pharmacological Aspects of Drugs Used for the Treatment of Drug-Resistant Tuberculosis in Adults and Children / Aspectos farmacológicos prácticos de las drogas para el tratamiento de la tuberculosis drogorresistente en adultos y pediatría

ABSTRACT The emergence of resistant strains of Mycobacterium tuberculosis to multiple drugs and the difficulties of their diagnosis and treatment constitute a challenge to global public health. To face this challenge, new anti-tuberculosis drugs, such as bedaquiline, pretomanid, and delamanid, as well as replacement drugs, such as fluoroquinolones, linezolid and clofazimine, are used. Based on the evidence provided by multicenter studies, drugs associated with a better prognosis of drug-resistant tuberculosis have been discovered and, recently, a new classification has been proposed, as well as new totally oral regimens. In this review, we describe current treatment regimens and practical pharmacological aspects required when prescribing new drug-resistant tuberculosis treatment regimens.

RESUMEN La emergencia de cepas resistentes de Mycobacterium tuberculosis a múltiples drogas, las dificultades de su diagnóstico y tratamiento constituyen un desafío a la salud pública mundial. Para afrontar esta situación, se emplean nuevas drogas antituberculosis, como bedaquilina, pretomanid y delamanid, así como drogas repropuestas, como fluoroquinolonas, linezolid y clofazimina. Con base en la evidencia brindada por estudios multicéntricos, se han descubierto fármacos asociados a un mejor pronóstico de la tuberculosis drogorresistente y, recientemente, se ha propuesto una nueva clasificación, así como nuevos esquemas totalmente orales. En esta revisión, describimos los esquemas de tratamiento actuales y los aspectos farmacológicos prácticos necesarios a la hora de la prescripción de los nuevos regímenes de tratamiento de la tuberculosis drogorresistente.

Aspectos farmacológicos prácticos de las drogas para el tratamiento de la tuberculosis drogorresistente en adultos y pediatría / Practical Pharmacological Aspects of Drugs Used for the Treatment of Drug-Resistant Tuberculosis in Adults and Children

La emergencia de cepas resistentes de Mycobacterium tuberculosis a múltiples drogas, las dificultades de su diagnóstico y tratamiento constituyen un desafío a la salud pública mundial. Para afrontar esta situación, se emplean nuevas drogas antituberculosis, como bedaquilina, pretomanid y delamanid, así como drogas repropuestas, como fluoroquinolonas, linezolid y clofazimina. Con base en la evidencia brindada por estudios multicéntricos, se han descubierto fármacos asociados a un mejor pronóstico de la tuberculosis drogorresistente y, recientemente, se ha propuesto una nueva clasificación, así como nuevos esquemas totalmente orales. En esta revisión, describimos los esquemas de tratamiento actuales y los aspectos farmacológicos prácticos necesarios a la hora de la prescripción de los nuevos regímenes de tratamiento de la tuberculosis drogorresistente.

The emergence of resistant strains of Mycobacterium tuberculosis to multiple drugs and the difficulties of their diagnosis and treatment constitute a challenge to global public health. To face this challenge, new anti-tuberculosis drugs, such as bedaquiline, pretomanid, and delamanid, as well as replacement drugs, such as fluoroquinolones, linezolid and clofazimine, are used. Based on the evidence provided by multicenter studies, drugs associated with a better prognosis of drug-resistant tuberculosis have been discovered and, recently, a new classification has been proposed, as well as new totally oral regimens. In this review, we describe current treatment regimens and practi cal pharmacological aspects required when prescribing new drug-resistant tuberculosis treatment regimens.

Tratamiento de la tuberculosis drogorresistente en adultos y niños. Revisión narrativa / Treatment of drug-resistant tuberculosis in adults and children. A narrative review

Resumen Desde 2018 han surgido a la luz de la evidencia importantes cambios en el tratamiento de la tuberculosis drogorresistente. El descubrimiento de nuevas drogas antituberculosis, como la bedaquilina y los derivados de nitroimidazopiranos, así como la utilización de drogas repropuestas, llevó a la recomendación de organismos internacionales de nuevos esquemas de tratamiento de la tuberculosis monorresistente y multidro gorresistente que son totalmente orales y así dejan de lado el uso prolongado de inyectables, con su inherente toxicidad e incomodidad. Algunas de las definiciones de tuberculosis drogorresistente han cambiado. También está en revisión el tiempo de su tratamiento y con algunos nuevos esquemas en estudio, como el BpaL (bedaquilina, pretomanid y linezolid), se ha logrado una duración similar a la del tratamiento de la tuberculosis pansensible. En esta revisión bibliográfica narrativa describimos las nuevas definiciones, algunos aspectos diagnósticos básicos, los aspectos farmacológicos y la nueva clasificación de las drogas a utilizar en el tratamiento de la tuberculosis drogorresistente, así como los esquemas actualmente propuestos para tratarla, contextualizados con la realidad nacional. Finalizamos con una breve reseña de los estudios clínicos en curso de nuevos esquemas acortados de tratamiento.

Abstract Since 2018, important changes in the treatment of drug-resistant tuberculosis have been produced in the light of new evidence. The discovery of new anti-tuberculosis drugs, such as bedaquiline and nitroimidazopirane derivatives, as well as the use of repurposed drugs, led to international organizations to recommend new, totally oral, treatment regimens for mono-resistant and multidrug-resistant tuberculosis, leaving aside the prolonged use of injectables, with their inherent toxicity and discomfort. Some definitions of drug-resistant tuberculosis have changed. The duration of treatment is also under review, leading some new regimens under study, such as BPaL (bedaquiline, pretomanid and linezolid), to a duration similar to that for treating susceptible tuberculosis. In this narrative review, we describe the new definitions, some basic diagnostic aspects, the pharmacological aspects, and the new classification of drugs to be used in the treatment of drug-resistant tuberculosis as well as the cur rently proposed schemes to treat it available within the Argentinean context. Finally, we include a brief review of ongoing clinical trials on new shortened treatments.

[Treatment of drug-resistant tuberculosis in adults and children. A narrative review]. / Tratamiento de la tuberculosis drogorresistente en adultos y niños. Revisión narrativa.

Since 2018, important changes in the treatment of drug-resistant tuberculosis have been produced in the light of new evidence. The discovery of new anti-tuberculosis drugs, such as bedaquiline and nitroimidazopirane derivatives, as well as the use of repurposed drugs, led to international organizations to recommend new, totally oral, treatment regimens for mono-resistant and multidrug-resistant tuberculosis, leaving aside the prolonged use of injectables, with their inherent toxicity and discomfort. Some definitions of drug-resistant tuberculosis have changed. The duration of treatment is also under review, leading some new regimens under study, such as BPaL (bedaquiline, pretomanid and linezolid), to a duration similar to that for treating susceptible tuberculosis. In this narrative review, we describe the new definitions, some basic diagnostic aspects, the pharmacological aspects, and the new classification of drugs to be used in the treatment of drug-resistant tuberculosis as well as the currently proposed schemes to treat it available within the Argentinean context. Finally, we include a brief review of ongoing clinical trials on new shortened treatments.

Desde 2018 han surgido a la luz de la evidencia importantes cambios en el tratamiento de la tuberculosis drogorresistente. El descubrimiento de nuevas drogas antituberculosis, como la bedaquilina y los derivados de nitroimidazopiranos, así como la utilización de drogas repropuestas, llevó a la recomendación de organismos internacionales de nuevos esquemas de tratamiento de la tuberculosis monorresistente y multidrogorresistente que son totalmente orales y así dejan de lado el uso prolongado de inyectables, con su inherente toxicidad e incomodidad. Algunas de las definiciones de tuberculosis drogorresistente han cambiado. También está en revisión el tiempo de su tratamiento y con algunos nuevos esquemas en estudio, como el BpaL (bedaquilina, pretomanid y linezolid), se ha logrado una duración similar a la del tratamiento de la tuberculosis pansensible. En esta revisión bibliográfica narrativa describimos las nuevas definiciones, algunos aspectos diagnósticos básicos, los aspectos farmacológicos y la nueva clasificación de las drogas a utilizar en el tratamiento de la tuberculosis drogorresistente, así como los esquemas actualmente propuestos para tratarla, contextualizados con la realidad nacional. Finalizamos con una breve reseña de los estudios clínicos en curso de nuevos esquemas acortados de tratamiento.

Primera serie de pacientes con TB-XDR y pre-XDR tratados con esquemas que incluyeron meropenem-clavulanato en Argentina / First Series of Patients With XDR and Pre-XDR TB Treated With Regimens That Included Meropenen-clavulanate in Argentina

La tuberculosis extensamente resistente (TB-XDR) y pre-XDR comprometen seriamente el pronóstico de la enfermedad, y su tratamiento requiere inevitablemente el uso de fármacos del grupo V (Organización Mundial de la Salud [OMS]). Se analizó retrospectivamente la evolución de todos los pacientes con TB pre-XDR y XDR asistidos en un servicio especializado durante 2012 y 2013, medicados con regímenes que incluyeron por lo menos 6 meses de meropenem-clavulanato (MPC), capreomicina, moxifloxacina, linezolid, clofazimina, isoniacida en alta dosis, PAS y en un caso bedaquilina. Fueron tratados 10 pacientes, 9 de ellos con un extenso patrón de resistencia a un mínimo de 6 fármacos y uno por reacciones adversas e interacciones medicamentosas que generaron una situación análoga. Ocho de los 10 pacientes tratados, hicieron la conversión bacteriológica del esputo (2 cultivos mensuales consecutivos negativos) en un lapso de 2 a 7 meses, en tanto que 2 fallecieron. No se observaron reacciones adversas atribuibles a la administración prolongada del MPC

XDR (extensively drug-resistant) and pre-XDR tuberculosis (TB) seriously compromise prognosis and treatment possibilities, and inevitably require the use of group V drugs (World Health Organization). The progress of all patients with XDR and pre-XDR TB seen in a specialized unit during 2012 and 2013 and treated with regimens that included at least 6 months of meropenem-clavulanate (MPC), capreomycin, moxifloxacin, linezolid, clofazimine, high-dose isoniazid, PAS, and bedaquiline in 1 case, were retrospectively analyzed. Ten patients were treated, 9 with an extensive pattern of resistance to at least 6 drugs, and 1 because of adverse reactions and drug interactions leading to a similar situation. Eight of the 10 patients treated achieved bacteriological sputum conversion (2 consecutive negative monthly cultures) over a period of 2–7 months, while 2 died. No adverse reactions attributable to prolonged administration of MPC were observed

First series of patients with XDR and pre-XDR TB treated with regimens that included meropenen-clavulanate in Argentina.

XDR (extensively drug-resistant) and pre-XDR tuberculosis (TB) seriously compromise prognosis and treatment possibilities, and inevitably require the use of group V drugs (World Health Organization). The progress of all patients with XDR and pre-XDR TB seen in a specialized unit during 2012 and 2013 and treated with regimens that included at least 6 months of meropenem-clavulanate (MPC), capreomycin, moxifloxacin, linezolid, clofazimine, high-dose isoniazid, PAS, and bedaquiline in 1 case, were retrospectively analysed. Ten patients were treated, 9 with an extensive pattern of resistance to at least 6 drugs, and 1 because of adverse reactions and drug interactions leading to a similar situation. Eight of the 10 patients treated achieved bacteriological sputum conversion (2 consecutive negative monthly cultures) over a period of 2-7 months, while 2 died. No adverse reactions attributable to prolonged administration of MPC were observed.

Successful alternative treatment of extensively drug-resistant tuberculosis in Argentina with a combination of linezolid, moxifloxacin and thioridazine.

OBJECTIVES: Current drug choices to treat extensively drug-resistant (XDR) tuberculosis (TB) are scarce; therefore, information on the safety, tolerability and efficacy of alternative regimens is of utmost importance. The aim of this study was to describe the management, drug adverse effects and outcome of alternative combined treatment in a series of XDR-TB patients. PATIENTS AND METHODS: A retrospective study was performed on 17 non-AIDS, pulmonary adult patients with XDR-TB admitted to a referral treatment centre for infectious diseases in Buenos Aires from 2002 through 2008. Drug susceptibility testing was performed under regular proficiency testing and confirmed at the national TB reference laboratory. RESULTS: Linezolid was included in the drug regimens of all patients; moxifloxacin and/or thioridazine were included in the regimens of 14 patients. Clinically tractable drug adverse effects were observed in nine patients, the most frequent being haematological disorders and neurotoxicity. In two patients, thioridazine was discontinued. Negative culture conversion was achieved in 15 patients, 11 completed treatment meeting cure criteria, 4 are still on follow-up with good evolution, 1 defaulted treatment and 1 was lost to follow-up. CONCLUSIONS: The combination of linezolid, moxifloxacin and thioridazine is recommended for compassionate use in specialized centres with expertise in the management of XDR-TB.

Experiencia argentina en el abordaje de la tuberculosis extensamente resistente / Extensively drug-resistant tuberculosis in Argentina: our experience

La tuberculosis extensamente resistente a múltiples drogas (XDR-TB), resistente a isoniacida, rifampicina, alguna fluoroquinolona y al menos una entre kanamicina, amikacina, o capreomicina; ha sido descripta en la mayoría de las regiones del mundo con efectos devastadores. Por esta razón, la información sobre seguridad, tolerabilidad y eficacia acerca de drogas potencialmente útiles en su tratamiento es de extrema utilidad, no sólo para mejorar el pronóstico individual de estos pacientes sino también para controlar su diseminación. Se presentan 18 casos de localización pulmonar en pacientes sin Sida. Se trataron con esquemas que incluyeron en todos los casos linezolida; en 13, moxifloxacina, y en 13, tioridazina, todos negativizaron al examen directo y cultivo del esputo. Once pacientes cumplieron criterios de curación, 6 están aún en tratamiento y 3 abandonaron. Diez pacientes presentaron efectos adversos, en sólo 1 caso debió suspenderse la tioridazina. La utilización de linezolid, moxifloxacina y tioridazina ha contribuído a la evolución satisfactoria de estos pacientes. Estos fármacos son considerados de utilidad en esta serie, pero deben ser empleados en centros especializados con experiencia en el manejo de la XDR-TB.(AU)

Experiencia argentina en el abordaje de la tuberculosis extensamente resistente / Extensively drug-resistant tuberculosis in Argentina: our experience

La tuberculosis extensamente resistente a múltiples drogas (XDR-TB), resistente a isoniacida, rifampicina, alguna fluoroquinolona y al menos una entre kanamicina, amikacina, o capreomicina; ha sido descripta en la mayoría de las regiones del mundo con efectos devastadores. Por esta razón, la información sobre seguridad, tolerabilidad y eficacia acerca de drogas potencialmente útiles en su tratamiento es de extrema utilidad, no sólo para mejorar el pronóstico individual de estos pacientes sino también para controlar su diseminación. Se presentan 18 casos de localización pulmonar en pacientes sin Sida. Se trataron con esquemas que incluyeron en todos los casos linezolida; en 13, moxifloxacina, y en 13, tioridazina, todos negativizaron al examen directo y cultivo del esputo. Once pacientes cumplieron criterios de curación, 6 están aún en tratamiento y 3 abandonaron. Diez pacientes presentaron efectos adversos, en sólo 1 caso debió suspenderse la tioridazina. La utilización de linezolid, moxifloxacina y tioridazina ha contribuído a la evolución satisfactoria de estos pacientes. Estos fármacos son considerados de utilidad en esta serie, pero deben ser empleados en centros especializados con experiencia en el manejo de la XDR-TB.

Patients with multidrug-resistant tuberculosis display impaired Th1 responses and enhanced regulatory T-cell levels in response to an outbreak of multidrug-resistant Mycobacterium tuberculosis M and Ra strains.

In Argentina, multidrug-resistant tuberculosis (MDR-TB) outbreaks emerged among hospitalized patients with AIDS in the early 1990s and thereafter disseminated to the immunocompetent community. Epidemiological, bacteriological, and genotyping data allowed the identification of certain MDR Mycobacterium tuberculosis outbreak strains, such as the so-called strain M of the Haarlem lineage and strain Ra of the Latin America and Mediterranean lineage. In the current study, we evaluated the immune responses induced by strains M and Ra in peripheral blood mononuclear cells from patients with active MDR-TB or fully drug-susceptible tuberculosis (S-TB) and in purified protein derivative-positive healthy controls (group N). Our results demonstrated that strain M was a weaker gamma interferon (IFN-gamma) inducer than H37Rv for group N. Strain M induced the highest interleukin-4 expression in CD4+ and CD8+ T cells from MDR- and S-TB patients, along with the lowest cytotoxic T-lymphocyte (CTL) activity in patients and controls. Hence, impairment of CTL activity is a hallmark of strain M and could be an evasion mechanism employed by this strain to avoid the killing of macrophages by M-specific CTL effectors. In addition, MDR-TB patients had an increased proportion of circulating regulatory T cells (Treg cells), and these cells were further expanded upon in vitro M. tuberculosis stimulation. Experimental Treg cell depletion increased IFN-gamma expression and CTL activity in TB patients, with M- and Ra-induced CTL responses remaining low in MDR-TB patients. Altogether, these results suggest that immunity to MDR strains might depend upon a balance between the individual host response and the ability of different M. tuberculosis genotypes to drive Th1 or Th2 profiles.

Tuberculosis extensamente resistente (XDR-TB) en Argentina: aspectos destacables epidemiológicos, bacteriológicos, terapéuticos y evolutivos / Extensively resistant tuberculosis (XDR-TB) in Argentina: epidemiology, bacteriology, therapy and outcome

La XDR-TB (resistente a isoniazida, rifampicina, alguna fluoroquinolona y al menos una entre kanamicina, amikacina o capreomicina), ha causado efectos devastadores en pacientes con SIDA y es prácticamente incurable. Se presentan 12 casos de localización pulmonar en pacientes no SIDA. Se trataron con esquemas que incluyeron en todos linezolid y en 9 moxifloxacino, todos negativizaron el examen directo y cultivo del esputo. Nueve pacientes cumplieron criterios de curación, 1 está aún en tratamiento y 2 abandonaron. Ocho pacientes presentaron efectos adversos, en solo 1 caso debió suspenderse la tioridazina. La utilización de linezolid, moxifloxacina y tioridazina han contribuido a la evolución satisfactoria de estos pacientes. Estos fármacos son considerados de utilidad en la serie reportada, debiendo ser utilizados en centros especializados con experiencia en el manejo de la TB MR y XDR-TB.

The XDR-TB (resistant to isoniazid, rifampiN, fluorquinolone and at least of the following: kanamycina, amikacyna or capreomycin), has caused devastating effects in patients with AIDS and is practically incurable. Twelve cases of pulmonary XDR-TB in non AIDS are described. All were treated with schemes that included linezolid in all and moxifloxacin in 9, all respiratory specimens became negative. Nine patients fulfilled healing criteria, 1 is still under treatment and 2 abandoned the therapy. Eight patients presented adverse effects, thioridazine was stopped in only one patient. Linezolid, moxifloxacin and tioridazin contributed to the satisfactory evolution of these patients. These drugs were considered useful in the reported series of cases and should be used in specialized centres with experience in the management of MR TB and XDR-TB.

[Tuberculosis treatment. A practical guide elaborated by the tuberculosis section, Argentine Association of Respiratory Medicine]. / Tratamiento de la tuberculosis. Guia practica elaborada por la seccion tuberculosis, Asociacion Argentina de Medicina Respiratoria.

Tuberculosis is a worldwide prevalent disease. The emergence of multidrug-resistant strains spurred the search for new drugs. There are several tuberculosis treatment guidelines, international and local in a programmatic approach. An Argentinean specialists panel draw practical guidelines based in clinical criteria and the local and international bibliography through consensus meetings, including issues as: antituberculosis drugs available in Argentina, initial and re-treatement modalities, special situations treatment, adverse reactions to antituberculosis drugs, current indications of surgical treatment and new drugs under study for the treatment of the disease.

Tratamiento de la tuberculosis: guia practica elaborada por la Seccion Tuberculosis, Asociacion Argentina de Medicina Respiratoria / Tuberculosis treatment: a practical guide elaborated by the Tuberculosis Section, Argentine Association of Respiratory Medicine

La tuberculosis es una enfermedad prevalente en todo el mundo. La emergencia de cepas multirresistentes del Mycobacterium tuberculosis ha incentivado la búsqueda de nuevos fármacos. Existen diversas guías de tratamiento de la enfermedad, internacionales y a nivel programático local. Un grupo de especialistas argentinos elaboró una guía práctica basada en criterios clínicos y en la bibliografía nacional e internacional sobre el tema a través de reuniones de consenso, abarcando tópicos como: fármacos antituberculosos disponibles en la Argentina, modalidades de tratamiento inicial y retratamiento, tratamiento en situaciones especiales, reacciones adversas a fármacos antituberculosos, indicaciones actuales de tratamiento quirúrgico y nuevos fármacos en estudio para el tratamiento de la enfermedad.(AU)

Tuberculosis is a worldwide prevalent disease. The emergence of multidrug-resistant strains spurred the search for new drugs. There are several tuberculosis treatment guidelines, international and local in a programmatic approach. An Argentinean specialists panel draw practical guidelines based in clinical criteria and the local and international bibliography through consensus meetings, including issues as: antituberculosis drugs available in Argentina, initial and re-treatement modalities, special situations treatment, adverse reactions to antituberculosis drugs, current indications of surgical treatment and new drugs under study for the treatment of the disease.(AU)

Tratamiento de la tuberculosis: guia practica elaborada por la Seccion Tuberculosis, Asociacion Argentina de Medicina Respiratoria / Tuberculosis treatment: a practical guide elaborated by the Tuberculosis Section, Argentine Association of Respiratory Medicine

La tuberculosis es una enfermedad prevalente en todo el mundo. La emergencia de cepas multirresistentes del Mycobacterium tuberculosis ha incentivado la búsqueda de nuevos fármacos. Existen diversas guías de tratamiento de la enfermedad, internacionales y a nivel programático local. Un grupo de especialistas argentinos elaboró una guía práctica basada en criterios clínicos y en la bibliografía nacional e internacional sobre el tema a través de reuniones de consenso, abarcando tópicos como: fármacos antituberculosos disponibles en la Argentina, modalidades de tratamiento inicial y retratamiento, tratamiento en situaciones especiales, reacciones adversas a fármacos antituberculosos, indicaciones actuales de tratamiento quirúrgico y nuevos fármacos en estudio para el tratamiento de la enfermedad.

Tuberculosis is a worldwide prevalent disease. The emergence of multidrug-resistant strains spurred the search for new drugs. There are several tuberculosis treatment guidelines, international and local in a programmatic approach. An Argentinean specialists panel draw practical guidelines based in clinical criteria and the local and international bibliography through consensus meetings, including issues as: antituberculosis drugs available in Argentina, initial and re-treatement modalities, special situations treatment, adverse reactions to antituberculosis drugs, current indications of surgical treatment and new drugs under study for the treatment of the disease.

Inhibition of Listeria innocua growth by antimicrobial-producing lactic acid cultures in vacuum-packed cold-smoked salmon.

The biopreservative potential of three antimicrobial-producing lactic acid bacteria strains was evaluated on cold-smoked salmon. Lactobacillus casei, Lactobacillus plantarum and Carnobacterium piscicola were added singly or in association to cold-smoked salmon, artificially contaminated with Listeria innocua and stored under vacuum for 30 days at 4 degrees C. All the lactic cultures were able to inhibit Listeria innocua growth, showing a bacteriostatic or bactericidal effect, without affecting negatively the sensory quality of the product. Lactobacillus casei was bacteriostatic when inoculated at 6 log cfu/g, but bactericidal at 8 log cfu/g, reducing Listeria innocua of 3.3 log cfu/g in comparison with the test at the end of storage. Lactobacillus plantarum and C. piscicola strains, inoculated singly at 6 log cfu/g reduced Listeria innocua counts of 2.8 and 2.7 log cfu/g, respectively, compared with the test. The association Lactobacillus casei-Lactobacillus plantarum was the most effective among the treatments with 6 log cfu/g inoculum, as Listeria innocua counts decreased of 3.2 log cfu/g compared with the test. The treatment with Lactobacillus casei-C. piscicola association was less effective than C. piscicola alone.

Multidrug-resistant tuberculosis in HIV-negative patients, Buenos Aires, Argentina.

Initial multidrug-resistant (MDR) tuberculosis (TB) in HIV-negative patients treated at a Buenos Aires referral hospital from 1991 to 2000 was examined by using molecular clustering of available isolates. Of 291 HIV-negative MDRTB patients, 79 were initially MDR. We observed an ascending trend of initial MDRTB during this decade (p=0.0033). The M strain, which was responsible for an institutional AIDS-associated outbreak that peaked in 1995 to 1997, caused 24 of the 49 initial MDRTB cases available for restriction fragment length polymorphism. Of those, 21 were diagnosed in 1997 or later. Hospital exposure increased the risk of acquiring M strain-associated MDRTB by approximately two and a half times. The emergence of initial MDRTB among HIV-negative patients after 1997 was apparently a sequel of the AIDS-related outbreak. Because the prevalence of M strain-associated disease in the study population did not level out by the end of the decade, further expansion of this disease is possible.

Potential of Lactobacillus casei , Culture Permeate, and Lacti Acid To Control Microorganisms in Ready-To-Use Vegetables.

The effects of various treatments (i.e., the addition of a strain of Lactobacillus that produces antimicrobial agents, Lactobacillus casei IMPC LC34, its sterile permeate, and 0.5 or 1% lactic acid) on the growth of microorganisms associated with ready-to-use mixed salad vegetables were compared during refrigerated (8°C) storage. The addition of 3% culture permeate to mixed salads reduced the total mesophilic bacteria counts from 6 to 1 log CFU/g, and suppressed coliforms, enterococci, and Aeromonas hydrophila after 6 days of storage at 8°C. A similar effect was shown when the L. casei culture was inoculated in the vegetables. One percent lactic acid had a bacteriostatic effect on the bacterial groups examined, except for total and fecal coliforms, which were reduced by about 2 and 1 log unit, respectively, while 0.5% lactic acid did not affect the indigenous microflora of the vegetables. The potential of these new hurdles to prevent the growth of spoilage and pathogenic bacteria in ready-to-use salad vegetables is suggested.

Asma ocupacional / Occupational asthma

En la cátedra de Neumonología (UBA) se estudiaron 31 pacientes con diagnóstico de asma ocupacional. Ellos se desempeñaron en 9 diferentes oficios principales, y otros secundarios; se hallaron expuestos a: polvos de algodón, lino, colorantes, isocianatos, harina de trigo, sílice y otros. Se registró un período de latencia promedio de 3,9 años. Todos tuvieron episodios de broncoespasmos; 38,7 por ciento revelaron eosinofilia periférica; de 15 en que se midíó IgE suérica se observaron elevaciones en el 66 por ciento. Doce hicieron pruebas de provocación inespecífica con MTC y fueron positivas en el 58,3 por ciento de los casos a dosis muy pequeñas, que correlataron con enfermos más graves. De los 31, 77,4 por ciento tuvieron espirometrías obstructivas, y del conjunto de ellos, 80 por ciento mejoraron con broncodilatadores. En 3 de ellos se hicieron pruebas serológicas de contrainmunoelectroforesis, que fueron positivas. Todos mejoraron cuando no inhalaban el ambiente laboral, durante las vacaciones, licencia médica prolongada, o cuando abandonaban el trabajo. (AU)