Leoncio Peregrino-Bejarano’s research while affiliated with Unidad Médica de Alta Especialidad Hospital de Pediatria Centro Médico Nacional Siglo XXI and other places

Background: Pediatric patients with febrile neutropenia usually receive a combination of broad spectrum antimicrobials. Treatment without aminoglycoside seems to have advantages. Objective: To compare the efficacy of piperacillin/tazobactam plus amikacin versus piperacillin/tazobactam. Methods: Randomized, open label, controlled clinical trial. Sample size for an efficacy of 55%, and delta of 25%; 80 episodes were required for each group. Selection criteria were patients with febrile neutropenia, candidates to receive parenteral antimicrobial treatment; they were randomized to one of two groups, piperacillin/tazobactam plus amikacin (Group A), or piperacillin/tazobactam (Group B). The outcomes were failure, adverse events and death. Mantel-Haenszel chi squaretest and exact Fisher test were used. Reduction of relative and absolute risk (RRR and ARR), 95% confidence intervals (CI 95%) and number needed to treat (NNT) were calculated. Results: 88 Episodes were analyzed in group A and 76 in group B. There was no statistical difference in general characteristics of patients or type of infections. There was not significant statistical difference in: failure 31.8% group A, 30.2% group B (RR 1.05, CI 95% 0.66-1.66, p = 0.86), or adverse events (one in each group). The RRR was 1.5%, and ARR 2%, with a NNT of 67. Conclusion: Piperacillin/tazobactam without amikacin was as effective as combination therapy in pediatric patients with febrile neutropenia.

Background: Genotyping tests were developed to attenuate the impact of viral resistance. Data on the use antiretroviral therapy genotype based in children is rare, and even more in low and middle-income countriesMethods:16 Children with ART failure and triple-class drug resistant viruses were included. Protease and retrotranscriptase genotypes were available for all patients. Switch of ART regimen was guided by genotyping data. The primary end point was virological suppression (<50 copies/mL) and immunological improvement after 48 weeks treatment with the new ART regimen. Results: The median age of the patients was 14.5 years (IQR 11-16.5). Median HIV-1 RNA viral load was 4.2 Log10 (IQR 3.4-4.8). The primary end point was found in 11 children (69%), and 13 children (81%) had an HIV-1 RNA viral load <200 copies/mL. Median (IQR) for the baseline CD4+ cell count was 382 cells/µL (281-686 cells/µL), whereas after 48 weeks treatment with the new ART regimen, it was 640 cells/µL (361-936 cells/µL) (P<0.001). Conclusions: Darunavir/ritonavir, Raltegravir, and Etravirine were well tolerated in the present pediatric population. These drugs provide good options for children exposed to extensive ART. Regimens guided by genotyping data were effective for children who had ART failure and multidrug-resistant HIV-1 infection.Pediatric Research (2016); doi:10.1038/pr.2016.53.

Introduction: Nosocomial infections are a major and a frequent problem in neonatal intensive care units and increase morbidity, mortality, and costs. The objective of this study was to identify the risk factors associated with nosocomial infections in a neonatal intensive care unit. Methods: Nested case control study. Records from patients were registered: gestational age, sex, birth weight, central venous catheter and other devices, congenital malformations, surgeries, mechanical ventilation, steroid use, H2 blockers, length of stay in neonatal intensive care unit, type of infection, and etiological agent. Results: We studied 188 cases with nosocomial infections and 192 controls without nosocomial infections. The most frequent infection was sepsis (34.8%) and coagulase negative Staphylococcus was the principal etiological agent (37.2%). The risk factors associated with nosocomial infection were central venous catheter (OR: 7.3; 95% CI: 2.3-22.8), duration of neonatal intensive care unit stay > 14 days (OR: 3.4; 95% CI: 1.7-6.7), H2 blockers (OR: 2.3; 95% CI: 1.2-4.2), number of surgeries ≥ 2 (OR: 3; 95% CI: 1.1-7.9) and mechanical ventilation > 7 days (OR: 2.1; 95% CI: 1.1-4.2). Conclusions: Some risk factors associated to nosocomial infections in this study are similar to those found previously, with the exception of the number of surgeries that was not reported in previous studies.

Background: Newborns who are admitted to neonatal intensive care units are at a high risk for the development of a nosocomial infection. The purpose of this study was to record the incidence and the type of nosocomial infections, the isolated microorganisms and the susceptibility profile of these newborns in a neonatal intensive care unit. Methods: A descriptive, prospective, longitudinal study was conducted over a 1-year period. Out of 113 newborns with nosocomial infection, demographic variables, antibiotic use prior to admission, central venous catheter use, type of nosocomial infection, isolated microorganism and susceptibility profile were recorded. Results: One hundred and forty nine nosocomial infection episodes were recorded, with an incidence of 37.7 × 100 discharges and an incidence density rate of 25.6 × 1000 patient-days. The most common nosocomial infections were central venous catheter colonization related bacteremia (35.5 %) and sepsis (28.8 %). The most common microorganisms were coagulase-negative Staphylococcus (43.4 %) and Klebsiella pneumoniae (21 %), out of which 97.3 % were extended-spectrum beta-lactamase-producers. Conclusions: The incidence of nosocomial infection was similar to that reported in developing countries. Central venous catheter colonization-related bacteremia and gram-positive bacteria were the most common nosocomial infection and causative microorganisms, respectively.

Background: Urinary tract infection is one of the most common infections at all ages. Antimicrobial resistance has increased in the past few years. The aim of this study was to determine the most common etiologic agents of urinary tract infections and their antimicrobial susceptibility profiles. Methods: A descriptive, cross-sectional survey was conducted. Patients with a urinary tract infection identified over a 1-year period were included. The type of infection, risk condition, antimicrobial treatment, microorganism and antimicrobial susceptibility were recorded. Statistical analysis: descriptive statistics. Results: One hundred and seventy four patients with infection, 31.4 % with urinary tract malformation, 56 % with functional abnormalities. 76.4 % were receiving antimicrobial prophylaxis. Escherichia coli was the most common agent isolated with 67%, followed by Klebsiella spp. 9 %, Pseudomonas spp. 7 % and others less frequently. Escherichia coli resistance to cephalotin was 58.7%, to norfloxacin 51 %, nitrofurantoin 15.5 %, cefuroxime 12.5 %, cefotaxime 15.5 %, cefepime 5 % and to amikacin 0 %. Conclusions: Escherichia coli was the most common causative agent, and resistance to quinolones and cephalotin was higher than 50 %. Most patients had urinary tract functional abnormalities and a history of prophylactic treatment use. Options other than quinolones need to be assessed due to the high resistance identified in uropathogens.

Biofilm production has been established as a virulence factor which allows Staphylococcus to adhere and persist in medical devices. The objective was to determine whether therapeutic failure in patients infected with Staphylococcus spp. is linked to biofilm production, the presence of the ica operon, and the bacterial insertion sequence element IS256. Staphylococcus spp. isolates from patients with device-related infections were collected. Therapeutic failure with proper antimicrobial treatment was registered. Biofilm phenotype was determined by Congo red test agar and Christensen assay. Presence of the ica operon genes A-D and IS256 was detected by PCR. Differences were compared through x2. 100 isolates from staphylococcal infections episodes were included: 40 sepsis/bacteremia, 32 ependymitis, and 28 peritonitis. 73.77% of CoNS and 79.5% of S. aureus isolates harbored the icaD gene, 29% of all isolates IS256-A+ IS256-D genes, icaA and icaB genes were only found in CoNS (27.8% and 21.3% respectively). Therapeutic failure occurred in 95.4.% of patients with a positive IS256-A+ IS256-D S. epidermidis isolate, RR 5.49 (CI 95% 2.24-13.44 p < or = 0.0001), and 85.76% in CoNS isolates, RR 2.57 (CI 95% 0.97-6.80, p = 0.05). Although none S. aureus was positive for IS256-A + IS256-D, therapeutic failure was observed in 35.8%. The presence of icaA/D genes along with the sequence element IS256 was associated with therapeutic failure in most CoNS infections, even though its absence in S. aureus isolates does not ensure therapeutic success.

Serratia marcescens is a well-recognized nosocomial pathogen. The objective of the study was to describe typing results using a rapid pulsed field gel electrophoresis (PFGE) protocol and infection control measures during an outbreak of Serratia marcescens in a 24-bed, referral, neonatal intensive care unit (NICU) of a tertiary-care pediatric hospital. Two patients with S. marcescens sepsis were identified in the NICU. Health care personnel of the unit were requested to reinforce infection control measures. Active surveillance was established to detect infected and/or colonized patients and environmental and staff reservoirs. Infected and colonized patients were cohorted on one side of the unit; admissions to NICU were limited. Isolates were typed with a short 2-day pulsed-field gel electrophoresis (PFGE) protocol. Thirty three patients were exposed during a period of 20 days. Ten S. marcescens isolates were obtained from six patients, in two from blood culture and in three from stool culture; a single clone was identified in four. S. marcescens was not isolated from environmental or staff cultures. PFGE results were obtained in 2 days, infection control measures were reinforced, outbreak was promptly interrupted, and the NICU remained opened.