RESUMO
Carbapenem-resistant significant members of Acinetobacter calcoaceticus-Acinetobacter baumannii (CR-SM-ACB) complex have emerged as an important cause of sepsis, especially in ICUs. This study demonstrates the application of loop-mediated-isothermal-amplification (LAMP) assay for detection of CR-SM-ACB-complex from patients with sepsis. Whole-blood and culture-broths(CB) collected from patients with culture-positive sepsis were subjected to LAMP and compared with PCR, and RealAmp. Vitek-2 system and conventional PCR results were used as confirmatory references. The sensitivity and specificity of LAMP(97 % & 100 %) and RealAmp(100 % & 100 %) for detection of CR-SM-ACB-complex from CB were better than PCR(87 % & 100 %). Diagnostic accuracy of LAMP, RealAmp, and PCR for detection of SM-ACB-complex from CB was 98.5 %, 100 %, and 88.5 % respectively. Turnaround time of Culture, LAMP, PCR, and RealAmp was 28-53, 6-20, 9-23, and 6-20hours, respectively. LAMP is a simple, inexpensive tool that can be applied directly to positive CB and may be customized to detect emerging pathogens and locally-prevalent resistance genes and to optimize antimicrobial use.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Acinetobacter calcoaceticus , Carbapenêmicos , Unidades de Terapia Intensiva , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Sensibilidade e Especificidade , Sepse , Humanos , Infecções por Acinetobacter/diagnóstico , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/economia , Sepse/diagnóstico , Sepse/microbiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/economia , Carbapenêmicos/farmacologia , Acinetobacter calcoaceticus/genética , Acinetobacter calcoaceticus/efeitos dos fármacos , Acinetobacter calcoaceticus/isolamento & purificação , Antibacterianos/farmacologia , Análise Custo-BenefícioRESUMO
BACKGROUND: Standard-of-care nucleic acid amplification tests (routine NAATs) for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) can take several days to result and therefore delay treatment. Rapid point-of-care GC/CT NAAT (rapid NAAT) could reduce the time to treatment and therefore onward transmission. This study evaluated the incremental cost per infectious day averted and overall cost of implementation associated with rapid compared with routine NAAT. METHODS: Prospective sexually transmitted infection (STI) treatment data from men who have sex with men and transgender women in San Diego who received rapid NAAT between November 2018 and February 2021 were evaluated. Historical time from testing to treatment for routine NAAT was abstracted from the literature. Costs per test for rapid and routine NAAT were calculated using a micro-costing approach. The incremental cost per infectious day averted comparing rapid to routine NAAT and the costs of rapid GC/CT NAAT implementation in San Diego Public Health STI clinics were calculated. RESULTS: Overall, 2333 individuals underwent rapid NAAT with a median time from sample collection to treatment of 2 days compared with 7 to 14 days for routine NAAT equating to a reduction of 5 to 12 days. The cost of rapid and routine GC/CT NAAT was $57.86 and $18.38 per test, respectively, with a cost-effectiveness of between $2.43 and $5.82 per infectious day averted. The incremental cost of rapid NAAT improved when at least 2000 tests were performed annually. CONCLUSIONS: Although rapid GC/CT NAAT is more expensive than routine testing, the reduction of infectious days between testing and treatment may reduce transmission and provide improved STI treatment services to patients.
Assuntos
Infecções por Chlamydia , Chlamydia trachomatis , Gonorreia , Homossexualidade Masculina , Neisseria gonorrhoeae , Técnicas de Amplificação de Ácido Nucleico , Humanos , Masculino , Gonorreia/diagnóstico , Gonorreia/economia , Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/economia , Técnicas de Amplificação de Ácido Nucleico/economia , Neisseria gonorrhoeae/isolamento & purificação , Chlamydia trachomatis/isolamento & purificação , Adulto , California/epidemiologia , Análise Custo-Benefício , Estudos Prospectivos , Feminino , Testes Imediatos/economia , Pessoas TransgêneroRESUMO
Background: Classical swine fever virus (CSFV) remains one of the most important pathogens in animal health. Pathogen detection relies on viral RNA extraction followed by RT-qPCR. Novel technologies are required to improve diagnosis at the point of care. Methods: A loop-mediated isothermal amplification (LAMP) PCR technique was developed, with primers designed considering all reported CSFV genotypes. The reaction was tested using both fluorometric and colorimetric detection, in comparison to the gold standard technique. Viral strains from three circulating CSFV genotypes were tested, as well as samples from infected animals. Other pathogens were also tested, to determine the LAMP specificity. Besides laboratory RNA extraction methods, a heating method for RNA release, readily available for adaptation to field conditions was evaluated. Results: Three primer sets were generated, with one of them showing better performance. This primer set proved capable of maintaining optimal performance at a wide range of amplification temperatures (60°C - 68°C). It was also able to detect CSFV RNA from the three genotypes tested. The assay was highly efficient in detection of samples from animals infected with field strains from two different genotypes, with multiple matrices being detected using both colorimetric and fluorometric methods. The LAMP assay was negative for all the unrelated pathogens tested, including Pestiviruses. The only doubtful result in both fluorometric and colorimetric LAMP was against the novel Pestivirus italiaense, ovine Italy Pestivirus (OVPV), which has proven to have cross-reaction with multiple CSFV diagnostic techniques. However, it is only possible to detect the OVPV in a doubtful result if the viral load is higher than 10000 viral particles. Conclusion: The results from the present study show that LAMP could be an important addition to the currently used molecular diagnostic techniques for CSFV. This technique could be used in remote locations, given that it can be adapted for successful use with minimal equipment and minimally invasive samples. The joined use of novel and traditional diagnostic techniques could prove to be a useful alternative to support the CSF control.