Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project.

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions. PHOTONGATE relies on two core technologies: a biochemical technology (molecular gates), which will confer the specificity and, therefore, the capability to be adaptable to the analyte of interest, and which, combined with porous substrates, will increase the sensitivity, and a photonic technology based on localized surface plasmonic resonance (LSPR) structures that serve as transducers for light interaction. Both technologies are in the micron range, facilitating the integration of multiple sensors within a small area (mm2). The concept will be developed for its application in health diagnosis and food safety sectors. It is thought of as an easy-to-use modular concept, which will consist of the sensing module, mainly of a microfluidics cartridge that will house the photonic sensor, and a platform for fluidic handling, optical interrogation, and signal processing. The platform will include a new optical concept, which is fully European Union Made, avoiding optical fibers and expensive optical components.

Mpox Infection and Sexually Transmitted Infections: A Cross-Sectional Study from a Secondary Hospital in the May-September 2022 International Outbreak.

The aims of this study were to describe the characteristics of patients infected by mpox in our setting, to determine the prevalence of mpox in samples that are classically used for diagnosing sexually transmitted infections (STIs) such as anal, urethral, pharyngeal, and urine, and to assess the prevalence of coinfection with STIs in the same samples. A cross-sectional study was conducted, collecting all confirmed cases of mpox between June and July 2022 using polymerase chain reaction. Sociodemographic data, HIV and other STI status, and prevalence of mpox and STIs in urethral, anal, pharyngeal, or urine samples were collected. Data from 22 patients were extracted, all of whom were men who have sex with men (MSM) and 54.5% were previously HIV positive. The median age was 43 years. All the skin samples were positive for mpox, followed by anal samples (n = 10, 45.5%). Mpox was isolated in 2 or more samples simultaneously in 12 (54%) cases. Nine (41%) patients were positive for an STI and four of them had more than one STIs (18.2%). Human mpox has been epidemiologically significant among MSM. Mpox should be investigated not only in skin lesions but also in samples classically used for STIs. Mpox, such as other STIs, shares ways of transmission and coinfection may be underdiagnosed.

Low rate of vaccination and risk of incident hepatitis A among HIV-infected men who have sex with men in Seville, Southern Spain.

BACKGROUND: Periodic outbreaks of hepatitis A (HAV) infection in men who have sex with men (MSM) have been reported. Low vaccination uptake in HIV-infected individuals could drive new outbreaks. We aimed at evaluating the incidence of and risk factors for HAV infection in people living with HIV (PLWH) in our area. We also assessed the rates of HAV vaccination. METHODS: This was a prospective cohort study. 915 patients were included, 272 (30%) of them were anti-HAV seronegative at baseline. RESULTS: Twenty-six (9.6%) susceptible individuals became infected. Incident cases peaked in 2009-2010 and 2017-2018. Incident HAV infection was independently associated with MSM [adjusted odds ratio (95% confidence ratio): 4.39 (1.35-14.27), p=0.014]. One hundred and five (38.6%) HAV seronegative patients were vaccinated, 21 (20%) of them did not respond, and one (1%) patient lost immunity against HAV. Four (29%) non-responders to vaccination showed incident HAV 5-9 years afterwards. CONCLUSIONS: The incidence of HAV infection in a cohort of well-controlled PLWH remains low and stable, with intermittent outbreaks involving mainly non-immunized MSM. A significant proportion of PLWH remain susceptible to HAV infection due to insufficient vaccine uptake and limited response to vaccination. Importantly, patients not responding to HAV vaccination continue at risk of infection.

Reduced neutralizing antibody response to SARS-CoV-2 vaccine booster dose in people living with HIV with severe immunosuppression.

The aim of this study was to assess the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among people living with HIV (PLWH) with severe immunosuppression, after a booster dose. The design was a case-control study nested in a prospective cohort of PLWH. All patients with CD4 cell count <200 cells/mm3 who had received additional dose of messenger RNA (mRNA) COVID-19 vaccine, after a standard immunization scheme were included. Control group: patients age- and sex-matched, with CD4 ≥ 200 cells/mm3 , in the ratio of 2:1. Antibody response to a booster dose (anti-S levels 33.8 ≥ BAU/mL) and neutralizing activity against SARS-CoV-2 B.1, B.1.617.2, and Omicron BA.1, BA.2, and BA.5 strains were assessed after the booster shot. Fifty-four PLWH were included, 18 with CD4 counts < 200 cells/mm3 . Fifty-one (94%) showed response to a booster dose. Response was less frequent in PLWH with CD4 < 200 cells/mm3 than in those with CD4 counts ≥ 200 cells/mm3 (15 [83%] vs. 36 [100%], p = 0.033). In the multivariate analysis, CD4 counts ≥ 200 cells/mm3 [incidence rate ratio (IRR) = 18.1 (95% confidence interval [CI]: 16.8-19.5), p < 0.001] was associated with a higher probability of showing antibody response. Neutralization activity against SARS-CoV-2 B.1, B.1.617, BA.1, and BA.2 strains was significantly inferior among individuals with CD4 counts < 200 cells/mm3 . In conclusion, among PLWH with CD4 counts < 200 cells/mm3 , the immune response elicited by mRNA additional vaccine dose is reduced.

Treatment of COVID-19 with convalescent plasma in patients with humoral immunodeficiency - Three consecutive cases and review of the literature.

Patients lacking humoral response have been suggested to develop a less severe COVID-19, but there are some reports with a prolonged, relapsing or deadly course. From April 2020, there is growing evidence on the benefits of COVID-19 convalescent plasma (CCP) for patients with humoral immunodeficiency. Most of them had a congenital primary immunodeficiency or were on treatment with anti CD20 antibodies. We report on three patients treated in our hospital and review thirty-one more cases described in the literature. All patients but three resolved clinical picture with CCP. A dose from 200 to 800ml was enough in most cases. Antibody levels after transfusion were negative or low, suggesting consumption of them in SARS-CoV-2 neutralization. These patients have a protracted clinical course shortened after CCP. CCP could be helpful for patients with humoral immunodeficiency. It avoid relapses and chronification. CCP should be transfused as early as possible in patients with COVID-19 and humoral immunodeficiency.

Treatment of COVID-19 with convalescent plasma in patients with humoral immunodeficiency – Three consecutive cases and review of the literature / Tratamiento de la COVID-19 con plasma de convalecientes en pacientes con inmunodeficiencia humoral. Tres casos consecutivos y revisión de la literatura

Patients lacking humoral response have been suggested to develop a less severe COVID-19, but there are some reports with a prolonged, relapsing or deadly course. From April 2020, there is growing evidence on the benefits of COVID-19 convalescent plasma (CCP) for patients with humoral immunodeficiency. Most of them had a congenital primary immunodeficiency or were on treatment with anti CD20 antibodies. We report on three patients treated in our hospital and review thirty-one more cases described in the literature. All patients but three resolved clinical picture with CCP. A dose from 200 to 800ml was enough in most cases. Antibody levels after transfusion were negative or low, suggesting consumption of them in SARS-CoV-2 neutralization. These patients have a protracted clinical course shortened after CCP. CCP could be helpful for patients with humoral immunodeficiency. It avoid relapses and chronification. CCP should be transfused as early as possible in patients with COVID-19 and humoral immunodeficiency.(AU)

Se ha sugerido que los pacientes carentes de respuesta inmune humoral desarrollan una forma menos severa de COVID-19, pero existen algunos casos de curso prolongado, recurrente o incluso mortal. Desde abril de 2020 existen evidencias de los beneficios del plasma de convalecientes de COVID-19 (PCC) en los pacientes con inmunodeficiencia humoral. La mayoría tienen una inmunodeficiencia congénita primaria o están recibiendo tratamiento con anticuerpos anti-CD20. Describimos tres pacientes con inmunodeficiencia humoral y COVID-19 tratados con PCC en nuestro centro y revisamos los 31 casos más descritos en la literatura. Todos resolvieron el cuadro clínico con PCC, salvo tres. Una dosis de 200-800 mL fue suficiente en la mayoría de los casos. Los niveles de anticuerpos tras la transfusión fueron negativos o bajos, sugiriendo el consumo de los mismos en la neutralización del SARS-CoV-2. Estos pacientes tienen un curso clínico prolongado que se acorta tras la administración del PCC. El PCC podría ser de utilidad en los pacientes con inmunodeficiencia humoral. Evita las recaídas y la cronificación de la COVID-19. El PCC debería transfundirse lo antes posible en los pacientes con COVID-19 e inmunodeficiencia humoral.(AU)

Severe immunosuppression is related to poorer immunogenicity to SARS-CoV-2 vaccines among people living with HIV.

OBJECTIVES: The aim of this study was to assess the immunogenicity of SARS-CoV-2 available vaccines among people living with HIV (PLWH) after a complete vaccination scheme, and determine predictors of seroconversion. METHODS: This multicentre prospective cohort study included 420 PLWH who had received a standard immunization, either with mRNA or adenoviral-vectored COVID-19 vaccines. Antibody response was evaluated within 1 to 2 months after the last dose of the vaccine with a quantitative determination of antitrimeric spike protein-specific IgG antibodies and IgG neutralizing antibodies. RESULTS: Overall, 384 of 420 PLWH (91%) showed antibody response to vaccination. Seroconversion was observed in 308 of 326 individuals with cluster of differentiation 4 (CD4) counts ≥350 cells/mm3 (95%), 55 of 61 PLWH with 200 to 349 cells/mm3 (90%), and 21 of 33 PLWH with CD4 counts <200 cells/mm3 (64%; p < 0.001). The median log10 IgG neutralization levels were 2.4 IU/mL (Q1-Q3, 1.0-3.1) among PLWH with CD4 counts <200 cells/mm3, 3.1 IU/mL (Q1-Q3, 2.8-3.4) for the 200 to 349 cells/mm3 group, and 3.1 IU/mL (Q1-Q3, 2.7-3.4) for PLWH with CD4 counts ≥350 cells/mm3 (p = 0.016). In the multivariate analysis, CD4 counts ≥350 cells/mm3 (OR: 7.10; 95% CI, 1.91-26.46; p = 0.004) and receiving mRNA-vectored COVID-19 vaccines (OR: 8.19; 95% CI, 3.24-20.70; p ≤ 0.001) were independently associated with a higher probability of response to vaccination. DISCUSSION: HIV-related immunosuppression impairs the antibody response to SARS-CoV-2 vaccines. Specific vaccination schemes should be urgently tailored in this setting, particularly in patients with CD4 cell counts <200 cells/µL. Adenoviral-vectored vaccines should be avoided in PLWH whenever possible.

Identification of IL-6 Signalling Components as Predictors of Severity and Outcome in COVID-19.

IL-6 is one of the major mediators of the hyper-inflammatory responses with complex biological functions as it can signal via different modes of action. IL-6 by classical signalling has anti-inflammatory and antibacterial activities, while trans-signalling mediates pro-inflammatory effects. The net biological effect of IL-6 is established by multiple factors beyond its absolute concentration. Here, we assess the relationship between IL-6 signalling variables [IL-6, soluble IL-6R (sIL-6R) and soluble gp130 (sgp130)] and outcomes in a cohort of 366 COVID-19 patients. The potential trans-signalling was evaluated by a ratio between the pro-inflammatory binary IL-6:sIL-6R complex and the inactive ternary IL-6:sIL-6R:sgp130 complex (binary/ternary complex) and the fold molar excess of sgp130 over sIL-6R (FME). Our data provide new evidence that high levels of IL-6, sIL-6R, sgp130, binary/ternary complex ratio, and low FME are independent predictors of COVID-19 severity in survivor patients (without death), and the combination of IL-6 + sIL-6R + sgp130 exhibited the most robust classification capacity. Conversely, in a subgroup of patients with a very poor prognosis, we found that high levels of IL-6 and low levels of sIL-6R, sgp130, and binary/ternary complex ratio were predictors of death. In this context, the highest predictive capacity corresponded to the combined analysis of IL-6 + FME + lymphopenia + creatinine. Herein, we present IL-6 signalling variables as a helpful tool for the early identification and stratification of patients with clear implications for treatment and clinical decision-making.

Orthohepevirus C infection as an emerging cause of acute hepatitis in Spain: First report in Europe.

BACKGROUND & AIM: Hepatitis E virus (HEV) was considered the only member of the Hepeviridae family with zoonotic potential. Nevertheless, this consideration has been reassessed owing to several reported cases of acute and chronic hepatitis linked to the Orthohepevirus C genus. Because the circulation of Orthohepevirus C in rodents has been described worldwide, the risk of zoonotic transmission is plausibly global. METHODS: Orthohepevirus C RNA was retrospectively evaluated in 2 cohorts of patients in Spain. The first cohort included patients with acute hepatitis without etiological diagnosis after screening for hepatotropic virus infection. The second cohort included patients diagnosed with acute HEV infection, defined as positivity for anti-HEV-IgM antibodies and/or detectable HEV RNA in serum. RESULTS: Cohort 1 comprised 169 patients (64.4% male, median age 43 years) and cohort 2 comprised 98 individuals (68.3% male, median age 45 years). Of the individuals included in Cohort 1, two (1.18%; 95% CI 0.2-3.8) had detectable Orthohepevirus C RNA in serum. In Cohort 2, of the 98 included patients, 58 showed detectable HEV RNA, while 40 only showed positivity for IgM antibodies. Among those bearing only IgM antibodies, Orthohepevirus C RNA was detected in 1 (2.5%; 95% CI 0.06-13.1) individual. All strains were consistent with genotype C1. The infection resulted in mild self-limiting acute hepatitis in 2 patients. Infection caused severe acute hepatitis in the remaining patient who died as a result of liver and renal failure. CONCLUSIONS: We described 3 cases of Orthohepevirus C in patients with acute hepatitis, resulting in the first description of this infection in Europe. The prevalence obtained in our study suggests that Orthohepevirus C could be an emerging disease in Europe. LAY SUMMARY: We describe the first cases of acute hepatitis related to rat hepatitis E virus in Europe. The prevalence found in our study suggest that rat hepatitis E virus could be considered an emerging disease in Europe.

Incidence of and factors associated with SARS-CoV-2 infection among people living with HIV in Southern Spain after one year of pandemic.

Whether people living with HIV (PLWH) are at greater risk of acquiring SARS-CoV-2 infection is currently unknown. Prospective serologic studies may allow seroincidence analyses, where all infections are accurately identified. Because of this, we evaluated the incidence of associated factors with and the clinical outcome of SARS-CoV-2 infection in PLWH in Southern Spain. This prospective cohort study included PLWH from a Tertiary University Hospital in Southern Spain. Patients were enrolled in the study if (1) they had attended as outpatients our Unit from 1 August 2019 to 8 February 2020 and (2) had two subsequent evaluations from 9 February 2020 to 4 March 2021. SARS-CoV-2 infections were diagnosed by PCR, antigen detection or serology. Seven hundred and nine PLWH were included in the study. Of them, 55 [7.8%, 95% confidence interval (95% CI) 5.9%-9.9%] patients developed SARS-CoV-2 infection. Between 18 May and 29 November 2020, the rate of seroconversion was 5.3% (95% CI: 3.1%-9.0%) for the general population in the area of Seville and 2.3% (95% CI: 1.3%-2.6%) for PLWH in this study (p = .001). After multivariable analysis, adjusted by age, sex, and risk factors for HIV infection, active tobacco use and CDC stage, active tobacco smoking was the only factor independently associated with lower risk of SARS-Cov-2 infection [Incidence rate ratio: 0.29 (95% CI 0.16-0.55) p < .001]. In conclusion, the incidence of SARS-CoV-2 infection among PLWH in Southern Spain during the ongoing pandemic was lower than that reported for the general population in the same area.

Limited Value of Single Sampling for IgM Antibody Determination as a Diagnostic Approach for Acute Hepatitis E Virus Infection.

The objective was to evaluate the accuracy of a single determination of IgM antibodies for hepatitis E virus (HEV) diagnosis in patients with acute hepatitis. A prospective study included patients with suspicion of HEV infection, defined as individuals with acute hepatitis showing negative results for serological and molecular markers of other hepatitis viruses. All patients were evaluated for hepatitis E virus infection, including both IgM antibodies and viral RNA determinations. Hepatitis E virus infection was defined as positivity for any of these markers. A total of 182 patients were included in the study, of whom 68 (37.4%) were diagnosed with HEV infection. Of these, 29 (42.6%) were positive for both IgM and HEV RNA, 25 (36.8%) were positive only for IgM antibodies, and 14 (20.6%) were positive only for HEV RNA. Considering only those individuals who were positive for IgM antibodies, 54 of the 68 total cases (79.4%) could be identified, showing a percentage of false-negative individuals of 20.6%. The diagnostic algorithm of hepatitis E virus infection in patients with acute hepatitis should include the determination of both IgM antibodies and HEV RNA because single sampling for IgM antibody determination led to an important proportion of misdiagnosed cases. IMPORTANCE In immunocompetent patients with a suspicion of hepatitis E virus (HEV) infection, single IgM antibody testing is typically applied. In this prospective study, we aimed to evaluate the accuracy of three different HEV screening approaches in patients with acute hepatitis, including approaches based on IgM determination, HEV RNA detection, and the combination of both. Our study shows that any diagnostic algorithm for HEV infection in patients with acute hepatitis should be based on the determination of both markers (IgM antibodies and HEV RNA) because single sampling for IgM antibodies results in an unacceptable number of false-negative results (20%). According to our results, the determination of HEV RNA should not be limited to immunosuppressed individuals because a high proportion of cases could be misdiagnosed.

Treatment of COVID-19 with convalescent plasma in patients with humoral immunodeficiency - Three consecutive cases and review of the literature.

Patients lacking humoral response have been suggested to develop a less severe COVID-19, but there are some reports with a prolonged, relapsing or deadly course. From April 2020, there is growing evidence on the benefits of COVID-19 convalescent plasma (CCP) for patients with humoral immunodeficiency. Most of them had a congenital primary immunodeficiency or were on treatment with anti CD20 antibodies. We report on three patients treated in our hospital and review thirty-one more cases described in the literature. All patients but three resolved clinical picture with CCP. A dose from 200 to 800ml was enough in most cases. Antibody levels after transfusion were negative or low, suggesting consumption of them in SARS-CoV-2 neutralization. These patients have a protracted clinical course shortened after CCP. CCP could be helpful for patients with humoral immunodeficiency. It avoid relapses and chronification. CCP should be transfused as early as possible in patients with COVID-19 and humoral immunodeficiency.

Comparison between Aptima® assays (Hologic) and the CoBAS® 6800 system (Roche) for the diagnosis of sexually transmitted infections caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium.

Nowadays, it is of utmost importance to use fully validated assays for molecular-based diagnosis. In the field of sexually transmitted disease (STD), Roche and Hologic provide assays for diagnosing Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), and Trichomonas vaginalis (TV). A total of 212 clinical samples were tested. Aptima® Combo 2 (detecting CT and NG), Aptima® M. genitalium and the Aptima® T. vaginalis on the Panther® system were compared to CoBAS® CT/NG and CoBAS® TV/MG running on the CoBAS® 6800 system. To solve the discrepancies, Allplex™ STI Essential assay (Seegene®) and/or Sanger DNA sequencing were used. The diagnostic performance was calculated by mean of the sensitivity and specificity parameters. Aptima® (sensitivity: 98.90%, specificity: 100%), CoBAS® (sensitivity 100%, specificity: 96.67%). The CoBAS® combo (CT/NG) failed detecting NG from an anal/rectum specimen, which is not included into the validated specimens of the assay. Aptima® combo 2 produced two false positives (CT and NG), not detected by the third tests. All the assays showed an optimal diagnostic capacity, meeting the requirements for IVD DNA-based assays. All products work optimally on automatic platforms, minimizing time and risk of contamination during handling.

Macrolide and fluoroquinolone resistance of Mycoplasma genitalium in southern Spain, 2018-2019.

OBJECTIVES: In recent years, resistance in Mycoplasma genitalium (MG) to first-line (azithromycin) and second-line (moxifloxacin) treatment has been increasingly reported worldwide, however, no data regarding the south of Spain are available. METHODS: To determine resistance rates, MG-positive samples collected from June 2018 to June 2019 were analysed by sequencing the 23S rRNA and parC genes. RESULTS: A total of 77 patients (24 men having sex with men (MSM), 30 heterosexual men and 23 women) were included. Resistance-associated mutations against macrolide and fluoroquinolones were found in 36.4% (95% CI 25.7% to 48.1%) and 9.1% (95% CI 3.7% to 17.8%) of the patients, respectively. Being MSM and having had another STI in the last year were significantly associated with macrolide-resistant MG infection, while no associations were found with resistance to fluoroquinolones. CONCLUSIONS: Testing for resistance to first-line and second-line drugs against MG should be recommended for the general population and mandatory for the MSM population. We suggest that empiric azithromycin use for STI management should be avoided.

Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis.

The vaginal microbiota has importance in preserving vaginal health and defending the host against disease. The advent of new molecular techniques and computer science has allowed researchers to discover microbial composition in depth and associate the structure of vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing. Certain Community-Sate Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species-particularly Lactobacillus crispatus-are more related to vaginal health. In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis-including sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition.

Detection of sexually transmitted disease-causing pathogens from direct clinical specimens with the multiplex PCR-based STD Direct Flow Chip Kit.

Pathogens causing sexually transmitted diseases (STDs) include viruses, bacteria, and parasites. The ability to rapidly and efficiently detect these pathogens in a single reaction still remains a health challenge. The aim of this study was to evaluate the clinical reliability and accuracy of the STD Direct Flow Chip Kit (Vitro, IVD-EC approved), which can simultaneously detect up to 9 different species of STD pathogens at once. This kit enables direct analysis-direct-PCR-of clinical specimens (urine, semen, endocervical, urethral, nasopharyngeal, and perianal swabs) without DNA purification for the following pathogens: Chlamydia trachomatis (serovars A-K and L1-L3), Haemophilus ducreyi, Herpes Simplex Virus (Types I and II), Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Treponema pallidum, Trichomonas vaginalis, and Ureaplasma. The Anyplex™ II STI-7 Detection Kit (Seegene, IVD-EC) was used as the reference's method. Existing discordances were resolved using either a third molecular assay or DNA sequencing. Clinical performance was evaluated at two different stages: (i) from purified DNA of three hundred and fifty-eight clinical specimens with a diagnostic sensitivity (SE) and specificity (SP) of 99.4% and 100%, respectively, and an agreement of 99% (kappa index, κ = 0.97) with the reference's method and; (ii) by direct-PCR from six hundred and thirty-three specimens rendering SE, SP, and agreement values of 98.4%, 99.9%, and 98.0% (κ = 0.95), respectively. The STD Direct Flow Chip Kit constitutes a promising alternative to routine procedures in diagnostic, allowing direct analysis of specimens and enabling the detection of a broad panel of pathogens.

Comparison between Aptima Assays (Hologic) and the Allplex STI Essential Assay (Seegene) for the diagnosis of Sexually transmitted infections.

Sexually transmitted infections (STIs) remain a worldwide problem and a severe threat to public health. The purpose of this study was to compare Aptima® Assays (Hologic®) and the Allplex™ STI Essential Assay (Seegene®) for the simultaneous detection of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Mycoplasma genitalium in clinical practice. The Aptima® assays (Hologic®) are based on a transcription-mediated amplification (TMA) method. The Allplex™ STI Essential assay (Seegene®) is based on a multiplex Real-Time PCR (RT-PCR) method. A total of 622 clinical samples from different anatomical sites were tested using both methods. A total of 88 (14.1%) and 66 (10.6%) positive samples were found for any of the TMA assays used and for the RT-PCR assay, respectively. Aptima® assays showed a slightly higher rate of positive results for all pathogens except for T. vaginalis, the results of which were similar to those obtained with Allplex™. The most commonly detected pathogen was C. trachomatis (37 samples; 5.9% using TMA assays) and the anatomical site with the highest prevalence of microorganisms was a non-urogenital site, the pharynx (27 positive samples; 4.3%). Using the Aptima® assays as reference method, the comparison showed that the average specificity of multiplex RT-PCR was 100.0% for the four pathogens. However an average sensitivity of 74.5% was observed, showing 95.2% (CI95%; 93.6-96.9) of overall concordance (κ = 0.80). In conclusion, the Aptima® assays show a higher sensitivity on a wide range of sample types compared to the Allplex™ assay.

Physico-chemical and microbiological changes in commercial tilapia (Oreochromis niloticus) during cold storage / Cambios fisico-químicos y microbiológicos en tilapia comercial (Oreochromis niloticus) durante almacenamiento refrigerado

Background: The microbiological and chemical processes are the main responsible for deterioration of fresh fish. Therefore, it is essential to avoid these processes by applying good manufacturing practices during fish handling, distribution and storage. Objective: The aim of this paper was to evaluate the physico-chemical and microbial changes in commercial tilapia (Oreochromis niloticus) during cold storage in order to establish the shelf life since its arrival at the supermarket. Methods: 27 aquacultured tilapia specimens were analyzed at 0, 2, 4, and 7 days of storage at 4ºC. Measurements of texture, color, water holding capacity, total volatile basic nitrogen (TVB-N), thiobarbituric acid index, ATP-related compounds, as well as microbial analyses were carried out. Results: The TVB-N content was high at the beginning of the study, remaining stable during the storage. Lipid oxidation of samples was minimum, so this process did not contribute to the fish spoilage. It was observed the breakdown of inosine-5'- monophosphate (IMP) into Ino (inosine), and Ino into Hx (hypoxantine). The texture parameters and colour underwent changes as a consequence of the fish spoilage. Low microbial counts were observed at day 0, but Enterobacteriaceae and mesophilic counts gradually increased throughout storage. Conclusions: The K1 -value showed the progressive spoilage of the fish during the cold storage. The decrease of hardness and firmness confirmed the loss of quality throughout the time of study. The low microbial counts at the beginning of the study demonstrated the good quality of the tilapia; however, the increase of the mesophilic counts at the end of the studied period showed that tilapia was not fit for human consumption at day 7.

Antecedentes: Los procesos microbiológicos y químicos son los principales responsables del deterioro del pescado fresco. Por tanto, es esencial evitar estos procesos aplicando buenas prácticas de fabricación durante la manipulación, distribución y almacenamiento del pescado. Objetivo: El objetivo de este trabajo fue evaluar los cambios físico-químicos y microbiológicos en tilapia comercial (Oreochromis niloticus) durante el almacenamiento refrigerado con el fin de establecer la vida útil desde su llegada al supermercado. Métodos: 27 especímenes de tilapia fueron analizados a día 0, 2, 4 y 7 de almacenamiento a 4 ºC. Se llevaron a cabo medidas de textura, color, capacidad de retención de agua, nitrógeno básico volátil total (N-BVT), índice del ácido tiobarbitúrico, compuestos relacionados con el ATP, así como análisis microbianos. Resultados: El contenido en N-BVT fue alto al principio del estudio, siendo estable durante el almacenamiento. La oxidación lipídica de las muestras fue mínima, por lo que este proceso no contribuyó al deterioro del pescado. Se observó la degradación de inosina-5'- monofosfato (IMP) a Ino (inosina), y de Ino a Hx (hipoxantina). Los parámetros de textura y color sufrieron cambios como consecuencia del deterioro del pescado. Se observaron bajos recuentos microbianos a día 0, pero los recuentos de Enterobacteriaceae y de mesófilos aumentaron gradualmente durante el almacenamiento. Conclusiones: El valor K1 mostró el deterioro progresivo del pescado durante el almacenamiento en refrigeración. La disminución de dureza y firmeza confirmó la pérdida de calidad a lo largo del tiempo de estudio. Los bajos recuentos microbianos al principio del estudio demostraron la buena calidad de la tilapia; sin embargo, el aumento de los recuentos de mesófilos al final del periodo estudiado mostraron que la tilapia no era adecuada para el consumo humado a día 7.