EVOLUCIÓN DE LAS COLONIZACIONES E INFECCIONES POR BACTERIAS PRODUCTORAS DE CARBAPENEMASAS EN UN HOSPITAL PEDIÁTRICO / EVOLUTION OF COLONIZATIONS AND INFECTIONS BY BACTERIA PRODUCERS OF CARBAPENEMASSES IN A HOSPITAL PEDIATRIC

La emergencia de bacterias productoras de carbapenemasas (BPC) representa un problema de salud pública. La vigilancia epidemiológica constituye una herramienta fundamental para el control de la diseminación

The emergence of carbapenemase-producing bacteria (PCBs) represents a public health problem. Epidemiological surveillance constitutes a fundamental tool for the control of dissemination

ESTUDIO DE LAS COINFECCIONES POR OTROS PATÓGENOS RESPIRATORIOS EN PACIENTES PEDIÁTRICOS CON DIAGNÓSTICO DE COVID-19 / STUDY OF COINFECTIONS BY OTHER PATHOGENS RESPIRATORY IN PEDIATRIC PATIENTS WITH DIAGNOSTICS FROM COVID-19

Introducción: La coinfección de COVID-19 con otros patógenos respiratorios en pediatría ha sido poco estudiada. Resulta de interés conocer las características y cuadro clínico de pacientes que presenten coinfecciones con COVID-19. Objetivo: Estudiar la coinfección de SARS-CoV-2 con patógenos incluidos en el Panel RP 2.0 FilmArray® en muestras de pacientes pediátricos en un hospital del tercer nivel. Materiales y métodos: Durante abril a agosto de 2021 se realizó un estudio prospectivo descriptivo sobre 21 muestras de Hisopado Nasofaríngeo de pacientes pediátricos positivos para SARS-CoV-2 (iAMP® COVID-19 Detection Kit de Atila Biosystems). Se procesaron por PCR multiplex Filmarray® RP 2.0. Luego se describieron las características y síntomas de los pacientes. Resultados: 12/21 (60%) fueron pacientes ambulatorios y 8/21 (40%) internados. El 57% de los pacientes fueron mayores de 5 años, el 24% menores de 1 año y el 19% entre 1 y 5 años. El síntoma más frecuente fue fiebre 18/21 (86%). El 90,5% (19/21) de las muestras no mostraron detección de otros patógenos. En una muestra se detectó Rhino/enterovirus y en otra Coronavirus NL63; ambas pertenecieron a dos pacientes con enfermedades de base. Conclusión: La tasa de coinfecciones fue del 9,5%. Este número podría deberse a la baja circulación de patógenos respiratorios en un contexto con medidas de prevención de los contagios. En el estado actual de incremento de circulación de virus respiratorios endémicos, es de interés la búsqueda de coinfecciones con COVID-19

Introduction: The co-infection of COVID-19 with other respiratory pathogens in pediatrics has been little studied. It is of interest to know the characteristics and clinical picture of patients who present co-infections with COVID-19. Objective: To study the co-infection of SARS-CoV-2 with pathogens included in the RP Panel 2.0 FilmArray® in samples from pediatric patients in a third-level hospital. Materials and methods: During April to August 2021, a prospective descriptive study was conducted on 21 Nasopharyngeal Swab samples from pediatrics patients positive for SARS-CoV-2 (iAMP® COVID-19 Detection Kit from Attila Biosystems). They were processed by PCR multiplex Filmarray® RP 2.0. The characteristics and symptoms of the patients were then described. Results: 12/21 (60%) were outpatients and 8/21 (40%) were hospitalized. 57% of patients were older than 5 years, 24% under 1 year and 19% between 1 and 5 years. The most frequent symptom was fever 18/21 (86%). 90,5% (19/21) of the samples showed no detection of other pathogens. Rhino/enterovirus was detected in one sample and NL63 in another Coronavirus; both belonged to two patients with underlying diseases. Conclusion: The rate of co-infections was 9,5%. This number could be dueto the low circulation of respiratory pathogens in a context with measures to prevent contagion. In the current state of increased circulation of endemic respiratory viruses, the search for co-infections with COVID-19 is of interest

Biodegradability of Chlorophenols in Surface Waters from the Urban Area of Buenos Aires.

Biodegradability of 2-Chlorophenol (2-CP), 3-Chlorophenol (3-CP), 4-Chlorophenol (4-CP), 2,4-Dichlorophenol (2,4-DCP) and 2,4,6 Trichlorophenol (2,4,6-TCP) has been tested in surface waters in the urban area of Buenos Aires. Samples were taken from the La Plata River and from the Reconquista and Matanza-Riachuelo basins, with a total amount of 18 sampling points. Water quality was established measuring chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and both Escherichia coli and Enterococcus counts. Biodegradability was carried out by a respirometric method, using a concentration of 20 mg L-1 of chlorophenol, and the surface water as inoculum. Chlorophenols concentration in the same water samples were simultaneously measured by a solid phase microextraction (SPME) procedure followed by gas chromatography-mass spectrometry (GC-MS). 2,4-DCP was the most degradable compound followed by 2,4,6-TCP, 4-CP, 3-CP and 2-CP. Biodegradability showed no correlation with compound concentration. At most sampling points the concentration was below the detection limit for all congeners. Biodegradability does not correlate even with COD, BOD5, or fecal contamination. Biodegradability assays highlighted information about bacterial exposure to contaminants that parameters routinely used for watercourse characterization do not reveal. For this reason, they might be a helpful tool to complete the characterization of a site.

Bordetella Bronchiseptica aislada en paciente con fibrosis quística / Isolation Bordetella bronchiseptica in a patients with cystic fibrosis

Presentamos el caso de una paciente de 15 años con Fibrosis Quística (FQ) en la cual, en dos oportunidades y con un intervalo de 2 años; se aisló Bordetella Bronchiseptica con idéntico perfil genético estudiado por electroforesis de campo pulsado. El mecanismo lesional de B. Bronchiseptica en el árbol bronquial de pacientes con FQ no esta claramente establecido, pero la habilidad de esta bacteria para inhibir la función de los leucocitos y su capacidad de adherirse a las células del epitelio bronquial explicaría su capacidad infectiva y su persistencia en el tracto respiratorio.

Bordetella Bronchiseptica aislada en paciente con fibrosis quística / Isolation Bordetella bronchiseptica in a patients with cystic fibrosis

Presentamos el caso de una paciente de 15 años con Fibrosis Quística (FQ) en la cual, en dos oportunidades y con un intervalo de 2 años; se aisló Bordetella Bronchiseptica con idéntico perfil genético estudiado por electroforesis de campo pulsado. El mecanismo lesional de B. Bronchiseptica en el árbol bronquial de pacientes con FQ no esta claramente establecido, pero la habilidad de esta bacteria para inhibir la función de los leucocitos y su capacidad de adherirse a las células del epitelio bronquial explicaría su capacidad infectiva y su persistencia en el tracto respiratorio.

[Isolation of Haemophilus influenzae serotypes from deep sites in sick children]. / Aislamiento de distintos serotipos de Haemophilus influenzae en muestras profundas de pacientes pediátricos.

Haemophilus influenzae (Hi) is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.

[Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study]. / Sistema automatizado de hemocultivos Bact-Alert: 5 vs 7 dias de incubación. Primer estudio multicéntrico argentino.

Bact-Alert automatized system for blood cultures: 5 vs 7 days of incubation. First Argentine multicentre study. Between January and December 2001, we analyzed 80,141 blood cultures by the Bact-Alert system (14,960 FAN aerobics, 3,855 FAN anaerobic, 11,114 standards aerobics, 11,367 standards anaerobic, 12,054 pediatrics and 26,791 FAN pediatrics bottles) and 44.235 series from 27.615 patients at eight hospitals of Buenos Aires city, one of La Plata city and three of the Buenos Aires province. A total of 13,657 blood cultures yielded a positive result. Only 181 of them had been detected as positive between the 5th and 7th day of incubation and only 26 (0.19%) had clinical significance (Staphylococcus aureus 3; coagulase negative staphylococci 2; Enterococcus faecalis 1; Streptococcus pneumoniae 2; Campylobacter spp 1; Escherichia coli 1; Enterobacter cloacae 1; Enterobacteraerogenes 1; Citrobacter freundii 1; Klebsiella pneumoniae 1; Proteus mirabilis 1; Serratia marcescens 4; yeasts 7, including one strain of Cryptococcus neoformans). Of the total of contaminants, 38% were isolated by the anaerobic standard (65% were Propionibacterium spp and 29% coagulase negative staphylococci), 31.2% by the FAN aerobic (33.3% difphteroids and 28.9% Bacillus spp), 11.8% by the pediatric, 9% by FAN pediatric, 8.33% by aerobic standard and 1.4% by FAN anaerobic bottle. Our results show that the prolonged incubation of blood cultures for more than 5 days using the Bact-Alert system is unnecessary.

Aislamiento de distintos serotipos de Haemophilus influenzae en muestras profundas de pacientes pediátricos / Isolation of Haemophilus influenzae serotypes from sterile sites in sick children

Haemophilus influenzae (Hi) es responsable de diversas enfermedades humanas como sepsis, meningitis, celulitis y osteoartritis. En este trabajo se investigó la recuperación de distintos serotipos de Hi en muestras profundas de pacientes pediátricos. Se estudiaron 179 aislamientos de 146 niños durante el periodo 1996-2002 en el Laboratorio de Microbiología del Hospital de Niños Superiora Sor María Ludovica, Argentina. La distribución de los serotipos fue la siguiente: 1 a, 112 b, 1 c,1 d, 4 e, 3 f y 24 no tipificables. A partir del establecimiento de la estrategia de vacunación universal anti Hi b en 1998 se observa una disminución notable del serotipo b y un aumento relativo de otros y no tipificables.

Haemophilus influenzae (Hi) is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.

Aislamiento de distintos serotipos de Haemophilus influenzae en muestras profundas de pacientes pediátricos. / [Isolation of Haemophilus influenzae serotypes from deep sites in sick children]

Haemophilus influenzae (Hi) is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.

Centrally applied atrial natriuretic factor diminishes bile secretion in the rat.

Little is known about the role of centrally applied peptides in the regulation of bile secretion. We previously reported that the intravenous injection of atrial natriuretic factor (ANF) reduces bile acid dependent flow without affecting portal venous pressure in the rat. In the present work, we studied the effects of centrally applied ANF on bile secretion and the possible pathways involved. Rats were cannulated in the brain lateral ventricle for the administration of 1, 10 and 100 ng/microl ANF. After 1 week, the common bile duct was cannulated and bile samples were collected every 15 min for 60 min after the administration of ANF. The excretion rate of various biliary components was assessed. Bile secretion experiments were also performed after bilateral truncal vagotomy or atropine administration to evaluate the participation of a vagal pathway. In addition, the role of the sympathetic system was addressed by combined administration of propranolol and phentolamine. Centrally applied ANF did not modify blood pressure but diminished bile flow and bile acid output. It also reduced sodium and potassium secretion but did not modify protein or phospholipid excretion. Neither bilateral truncal vagotomy nor atropine administration abolished ANF response. Furthermore, combined administration of adrenergic antagonists did not alter ANF inhibitory effect on bile flow. In conclusion, centrally applied ANF reduced bile acid dependent flow not through a vagal or adrenergic pathway in the rat, suggesting the involvement of a peptidergic pathway.

Serum bile acids and pruritus in hemodialysis patients.

BACKGROUND: Chronic renal failure (CRF) patients usually suffer from pruritus. The pathophysiology of pruritus is still incompletely understood. SUBJECTS, MATERIALS AND METHODS: In this paper we determined serum total bile acids (STBA) in hemodialysis patients with advanced CRF (ACRF) in order to obtain STBA concentration in predialysis, to assess their probable relation among patients with pruritus and in postdialysis using a polysulfone membrane for dialysis. STBA were determined in 49 ACRF patients with chronic hemodialysis and values were compared to 20 control subjects. Hemodialysis patients were divided in two groups: with and without pruritus. In all these patients, month of renal replacement therapy, diabetic patients, dose of dialysis (Kt/V), viral markers, serum creatinine, serum glucose, aspartate and alanine aminotransferase, alkaline phosphatase, hematocrits and albumin were determined. The intensity of itching among pruritic patients was measured by a score system: mild (M), moderate (MO) and severe (S). RESULTS: No significant differences were found in patients with and without pruritus in months of renal replacement therapy, duration of dialysis or dose of dialysis (Kt/V). STBA were determined in all ACRF patients in predialysis and they showed significant differences compared to controls (p < 0.05), however, no differences were observed in the results obtained when control subjects were compared to ACRF patients without pruritus. Also in predialysis, pruritic patients showed significant differences in STBA compared to patients without pruritus (p < 0.001). STBA concentration showed a significant decrease in postdialysis using a polysulfone membrane in ACRF patients with and without pruritus. Finally, correlation with STBA and itch score of pruritus was significant (p < 0.02). CONCLUSION: Hemodialysis patients with ACRF and pruritus showed an increase of STBA in predialysis and a decrease in postdialysis.

Proliferative and morphological changes induced by vanadium compounds on Swiss 3T3 fibroblasts.

Vanadium compounds are shown to have a mitogenic effect on fibroblast cells. The effects of vanadate, vanadyl and pervanadate on the proliferation and morphological changes of Swiss 3T3 cells in culture are compared. Vanadium derivatives induced cell proliferation in a biphasic manner, with a toxic-like effect at doses over 50 microM, after 24 h of incubation. Vanadyl and vanadate were equally potent at 2.5-10 microM. At 50 microM vanadate inhibited cell proliferation, whereas slight inhibition was observed at 100 microM of vanadyl. At 10 microM pervanadate was as potent as vanadate and vanadyl in stimulating fibroblast proliferation, but no effect was observed at lower concentrations. A pronounced cytotoxic-like effect was induced by pervanadate at 50 microM. All of these effects were accompanied by morphological changes: transformation of fibroblast shape from polygonal to fusiform; retraction with cytoplasm condensation; and loss of lamellar processes. The magnitude of these transformations correlates with the potency of vanadium derivatives to induce a cytotoxic-like effect: pervanadate > vanadate > vanadyl. These data suggest that the oxidation state and coordination geometry of vanadium determine the degree of the cytotoxicity.

Effect of vanadium compounds on acid phosphatase activity.

The direct effect of different vanadium compounds on acid phosphatase (ACP) activity was investigated. Vanadate and vanadyl but not pervanadate inhibited the wheat germ ACP activity. These vanadium derivatives did not alter the fibroblast Swiss 3T3 soluble fraction ACP activity. Using inhibitors of tyrosine phosphatases (PTPases), the wheat germ ACP was partially characterized as a PTPase. This study suggests that the inhibitory ability of different vanadium derivatives to modulate ACP activity seems to depend on the geometry around the vanadium atom more than on the oxidation state. Our results indicate a correlation between the PTPase activity and the sensitivity to vanadate and vanadyl cation.

Quantitative modifications induced by angiotensin II on rat bile secretion.

Angiotensin II (ANG II) effects on bile secretion were studied in the rat. ANG II (0.1 microgram/kg) was injected into the jugular vein every 30 min and bile samples of 30 min were collected for 120 min. Blood arterial and portal venous pressures were simultaneously recorded before and after the administration of ANG II. Results showed that ANG II decreased bile flow and the excretion of sodium, potassium, chloride and bile acids whereas it increased pH, bile osmolality and the excretion rate of bicarbonate and calcium. ANG II also led to a rapid increase in mean arterial pressure as well as portal venous pressure which reverted to control values within 1 min. The present results suggest that ANG II may modulate bile flow and the excretion rate of the different biliary constituents. We have previously investigated atrial natriuretic factor effects on bile secretion and although the atrial factor antagonizes most of ANG II biological actions, unexpectedly, ANG II effects on bile secretion were not opposite to those of atrial natriuretic peptide. The modifications induced by ANG II on bile secretion may play an important role in pathophysiological conditions such as hypertensive states with increased ANG II circulating levels.

Morphologic changes in livers of hamsters treated with high doses of ursodeoxycholic acid: correlation with bile acids in bile.

The effects of high doses of ursodeoxycholic acid on bile acid composition and the liver morphology was examined in 60 male Syrian golden hamsters. The animals were allocated to five groups: I, control; II and IV received 0.5 g and 1 g of ursodeoxycholic acid per 100 g of standard diet respectively over 30 days and III and V received 0.5 g and 1 g of ursodeoxycholic acid per 100 g of standard diet respectively over 60 days. Bile acids were determined by high performance liquid chromatography. In all treated groups there was a significant increase in chenodeoxycholic and lithocholic acid in the bile. The mean glyco/tauro ratio was significantly higher than in the control group, reaching values > 1 for individual bile acids, except for lithocholic acid values which remained < 1. Under light microscopy, the livers of the hamsters showed damage which was dose/time related, namely portal inflammatory infiltrate, bile duct proliferation, cholestasis, fat infiltration and necrosis. Electron microscopy revealed pronounced changes starting with microvilli edema and extending to canalicular membrane destruction and necrosis. The changes observed in the relation glyco/tauro lithocholic acids, may be due to defence mechanisms to avoid hepatotoxicity. The hepatotoxicity resulting from ursodeoxycholic acid administration is presumed to be due primarily to lithocholic acid or some lithocholic acid metabolite.

Atrial natriuretic factor modifies bile flow and composition in the rat.

The effects of atrial natriuretic factor (ANF) on bile secretion were studied in the rat. ANF was injected 'in bolus' (5.0 micrograms/kg) every 30 min into the jugular vein. The common bile duct was cannulated and bile samples were collected every 30 min for 120 min. Systemic blood arterial pressure was registered before and after the administration of ANF. Results showed that ANF decreased bile flow and the excretion rate of sodium, potassium, chloride, bile acids, cholesterol and proteins. On the other hand, it increased pH and the excretion of bicarbonate and calcium. As ANF slightly reduces mean arterial pressure, its vascular effect may not be considered the major event. In addition, increased excretion of bicarbonate and calcium, and the fact that ANF vascular effect is short in time suggest that the peptide may have a non-vascular effect on the processes of bile formation and its modifications along the bile ducts. This extravascular effect may be exerted on the hepatocyte ions exchangers and/or at the ductal level on the processes of excretion and reabsorption of electrolytes and water.

Relationship between serum concentrations of flecainide and fluoride in humans.

The biotransformation of flecainide to serum fluoride after the oral administration of 100 mg to six healthy subjects was studied. Fluoride, flecainide acetate, calcium and alkaline phosphatase serum levels were determined at 0, 3, 4.5 and 6 hours after administration. Higher mean serum concentrations for fluoride and alkaline phosphatase (P less than 0.01, P less than 0.005) and lower mean calcium levels (P less than 0.05) were reached at 4.5 hours. The flecainide acetate serum levels ranged from 108 to 261 ng/ml. The results were analyzed for statistical significance by single factor analysis of variance with repeated measures. The Spearman rank correlation coefficient between flecainide acetate and fluoride serum increases was calculated. Our results would suggest that fluorine-containing flecainide could be biotransformed to yield some ionic fluoride which contribute to the daily fluoride intake.

Effect of ursodeoxycholic acid administration on bile acid composition in hamster bile.

The modification in the composition of bile acids in hamster by the administration of high dose of ursodeoxycholic acid (UDCA) was investigated. Male Golden Syrian hamsters were divided into five groups: a control group, two groups that received 0.5 g of UDCA per 100 g of standard diet during 30 and 60 days and another two groups that received 1 g of UDCA per 100 g of standard diet during 30 and 60 days. After ether anaesthesia the gallbladder was removed and bile was immediately aspirated. Bile acids were determined by high performance liquid chromatography (HPLC). Taurolithocholic (TLCA) and glycolithocholic acids (GLCA) increased significantly in all treated groups. The glyco/tauro ratio of 0.69 in controls became more than 1 in treated animals except in the case of lithocholic acid (LCA) conjugates which remained less than 1. UDCA derivatives increased proportionally to the administered dose and the cholic/cheno ratio diminished significantly. A moderate increase of 3- and 7-keto derivatives of chenodeoxycholic acid (CDCA) was observed in all treated groups but the above mentioned increment was especially evident in 3-keto derivatives. A high percentage of UDCA administered in the hamster was likely transformed to CDCA and the glyco conjugates of the bile acids were the predominant species except for the LCA derivatives.