Examinando por Autor "Olivo Lopez, Jose Maria"

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Carbapenemases in Pseudomonas aeruginosa in Isolates from Hospitalized Patients of a National Hospital in San Juan de Miraflores, January to June 2017, Lima
(Universidad Privada Norbert Wiener, 1905-07-09) Carranza Vásquez, Sherley Merlid; Vasquez Quispe, Walter Ivan; Olivo Lopez, Jose Maria
Pseudomonas aeruginosa is one of the most common pathogens causing infections in hospitalized patients and produces various resistance mechanisms, among which carbapenemases that hydrolyze all beta-lactams are significant. The objective of our study was to determine the types of carbapenemases found in Pseudomonas aeruginosa isolates from hospitalized patients at a national hospital in San Juan de Miraflores, Lima in 2017. A basic, descriptive, prospective, and cross-sectional study was conducted, including 150 non-repeated Pseudomonas aeruginosa isolates from hospitalized patients, with sensitivity tests performed by disk diffusion according to CLSI 2017. Of these, 80 strains were suspected of producing carbapenemases. The phenotypic test for carbapenemase detection used the disk approximation method with substrates (imipenem and meropenem) and inhibitors (EDTA and ABP) according to the INEI-ANLIS Dr. C. Malbrán recommended algorithm. Results showed 3 (4%) strains positive for carbapenemases. We conclude that the type of carbapenemase found in Pseudomonas aeruginosa was 4%, corresponding to the detection of metallo-beta-lactamases, indicated by the synergistic effect between imipenem and EDTA. No serine carbapenemases were detected.
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Comparison of two methods for the detection of residual antimicrobial activity in urine cultures processed at the National Teaching Hospital Madre Niño San Bartolomé
(Universidad Privada Norbert Wiener, 1905-07-07) Rodriguez Vera, Claudia Liliana; Olivo Lopez, Jose Maria
Objective: To determine which method, paper diffusion or direct inoculation, detects residual antimicrobial activity more frequently in urine cultures processed at the National Mother-Child Teaching Hospital in San Bartolomé. Materials and Methods: A descriptive, cross-sectional study was conducted from January to March 2014, processing 2024 urine samples from outpatients and hospitalized patients. For both methods to detect residual antimicrobial activity, the samples were inoculated on Muller Hinton agar plates with the Bacillus subtilis ATCC 6633 sensor strain at a 0.5 McFarland scale. In the paper diffusion method, 10 µL of urine was applied on a disk, while in the direct inoculation method, 1 µL of urine was directly inoculated on the agar plate with a sterile loop. Both plates were incubated at 37°C for 24 hours. The presence of an inhibition zone around the disk or direct inoculation point was considered as the presence of residual antimicrobial activity. The absence of an inhibition zone was considered as the absence of residual antimicrobial activity. Results: Residual antimicrobial activity was detected in 9.7% (196/2024) of the urine samples using the paper diffusion method, compared to 6.4% (129/2024) using the direct inoculation method. Moreover, 67 (3.3%) urine samples showed residual antimicrobial activity detected only by the paper diffusion method. In total, 1828 (90.3%) samples showed no residual antimicrobial activity with either method, and 129 (6.4%) showed residual antimicrobial activity. Conclusions: The paper diffusion method has a higher detection rate for residual antimicrobial activity in urine samples processed at the National Mother-Child Teaching Hospital in San Bartolomé.
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Diagnostic performance of the ISO 6579:2002 horizontal culture method versus the FDA-BAM method for the isolation of Salmonella SPP. in egg products.
(Universidad Privada Norbert Wiener, 2020-02-13) Pio Davila, Liz Gisella; Olivo Lopez, Jose Maria
The objective was to determine the diagnostic performance of the horizontal culture method (ISO 6579: 2002) and the FDA-BAM method for the isolation of Salmonella spp. in egg products. Methodology: A descriptive, cross-sectional, prospective study was carried out at the VADIS egg processing plant. Processing was done using the ISO 6579: 2002 and FDA-BAM methods. The egg products analyzed included egg yolk, filtered egg, unpasteurized yolk, and egg white. Diagnostic tests were performed, and the overall agreement between the tests was evaluated using Cohen’s Kappa coefficient. Results: A total of 1,130,580 eggs were processed over 15 weeks, with an average of 75,372 ± 47,045 eggs per week. The ISO 6579: 2002 horizontal culture method showed a sensitivity of 100% (95% CI: 9.5 to 90.5%), a specificity of 99.3% (95% CI: 97.6 to 100%), and an accuracy of 99.4% (95% CI: 96.5 to 99.9%). Good diagnostic concordance (K = 0.80), an observed total concordance ratio of 0.99, and an expected random concordance ratio of 0.97 were found. Conclusion: This study demonstrated the optimal diagnostic performance of the horizontal culture method ISO 6579: 2002 compared to the FDA-BAM method for the isolation of Salmonella spp. in egg products.
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Evaluation of Zika virus infection in the C6/36 HT and BHK-21 cell lines
(Universidad Privada Norbert Wiener, 2019-06-20) Medrano Contreras, Johanna Karolaine; Varillas Eguizabal, Benjamín Levy; Olivo Lopez, Jose Maria
Currently, the C6/36HT cell culture is primarily used for the isolation, identification, and characterization of the Zika virus. The main objective of this study was to evaluate the infectivity of the Zika virus in the C6/36HT and BHK-21 cell lines. A descriptive, non-experimental, longitudinal study was conducted, where four viral titers were tested in each cell line. The virus was inoculated in both cell lines, and the cytopathic effect (CPE) was observed for eight days. Afterward, immunofluorescence was used to identify infected cells. The BHK C-21 cell line showed CPE from the third day, reaching 100% of cells with various cellular alterations, whereas the C6/36HT line showed only 25% CPE from the fourth day, which was statistically significant with p <0.05 at the highest concentration titer. Immunofluorescence showed cellular infectivity at 24 hours post-inoculation in the C6/36HT line and at 72 hours in the BHK-21 line, with no statistically significant differences at any of the titers (p > 0.05). Therefore, it can be concluded that the BHK cell line showed a cytopathic effect in a shorter inoculation time, while the C6/36HT cells demonstrated infected cells in a shorter time, but with slower replication and higher cellular lysis and alterations.
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Profile of sensitivity in extended-Spectrum Beta-Lactamase-Producing Enterobacteria isolated from urine cultures of pediatric patients with urinary infections. Hipólito Unanue National Hospital. 2015
(Universidad Privada Norbert Wiener, 1905-07-09) Fonseca Taipe, Francisco; Olivo Lopez, Jose Maria
Urinary tract infections in pediatric patients are mainly caused by enterobacteria, which are gram-negative bacilli capable of producing a variety of beta-lactamase enzymes, including extended-spectrum beta-lactamases, a family of enzymes that inactivate a broader spectrum of beta-lactam antibiotics. OBJECTIVE: To determine the sensitivity profiles of extended-spectrum beta-lactamase-producing enterobacteria isolated from urine cultures of pediatric patients with urinary tract infections at the National Hospital Hipólito Unanue, Lima, 2015. MATERIAL AND METHODS: The data collection tool used was the program Whonet 6.4. A descriptive, quantitative, retrospective, and cross-sectional study was conducted. RESULTS: Of a total of 702 urine cultures analyzed from January to December 2015, 161 strains of gram-negative enterobacteria were isolated. Of these, 40 strains were identified as extended-spectrum beta-lactamase producers (24.8%), using the disk diffusion method on Mueller Hinton agar through the Kirby Bauer technique. To confirm the detection of extended-spectrum beta-lactamases, the Jarlier method was used. The strains mainly identified were E. coli, Klebsiella pneumoniae, and Proteus mirabilis, mostly affecting females (70%) and primarily those aged 1 to 4 years, representing 52.5%. CONCLUSION: The sensitivity profiles of extended-spectrum beta-lactamase-producing enterobacteria to non-beta-lactam antibiotics were: nitrofurantoin (89%), amikacin (87%), gentamicin (47%), showing high resistance to sulfamethoxazole-trimethoprim (95%), nalidixic acid (80%), and ciprofloxacin (70%).
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Relationship Between Bacilloscopy Results and Ogawa-Kudoh Culture for the Diagnosis of Extrapulmonary Tuberculosis in a General Hospital in El Agustino District, Lima 2016-2017
(Universidad Privada Norbert Wiener, 2018-06-08) Pasco Chavez, Israel Ayrton; Saman Ballarta, Jhonatan Alexis; Olivo Lopez, Jose Maria
Introduction: Extrapulmonary tuberculosis is an infection caused by Mycobacterium tuberculosis, which affects tissues and organs outside the lungs in 20-25% of tuberculosis cases. The objective was to determine the relationship between the results of bacilloscopy and Ogawa-Kudoh culture for the diagnosis of extrapulmonary tuberculosis. Methodology: In this correlational, retrospective, cross-sectional study, extrapulmonary samples were processed for microbiological diagnosis of TB. Four types of samples were included: gastric aspirate, stool, urine, and pleural fluid. Results: Out of 5,299 extrapulmonary samples, 3,700 (69.8%) were concordant and 161 (3%) were discordant. Diagnostic concordance analysis showed moderate agreement (κ=0.54, 95% CI 0.48 to 0.61) between both diagnostic tests for extrapulmonary tuberculosis. The frequency of positive results in the study samples was 245 (4.6%) for bacilloscopy and 239 (4.5%) for Ogawa-Kudoh culture, while the frequency of negative bacilloscopy results was 4,931 (93.1%), and 3,781 (71.4%) for the culture. Of the included samples, 278 (5.2%) had contaminated cultures. Conclusion: There is a relationship between the results of bacilloscopy and Ogawa-Kudoh culture methods in the diagnosis of tuberculosis at a general hospital in the El Agustino district, showing moderate concordance.