Microbiological Quality of Oysters and Mussels Along Its Market Supply Chain.

Oysters and mussels are known vectors of foodborne pathogens because of their immobile and filter-feeding nature leading to the accumulation of biological particles in their tissues. Accumulated bacteria which comes from the culture environment and unsanitary handling can cause food poisoning if these shellfish are consumed raw or partially processed. This study determined the incidence of bacterial pathogen contamination along the different channels of the oyster and mussel supply chain through a time-distribution simulation analysis. First, the route of the fresh bivalve products from a local farm to its market was established through interviews. From the data gathered, a simulation experiment was conducted following the observed time-temperature conditions and the actual bulk packaging material used by the traders. The presence of target pathogens Escherichia coli, Salmonella spp., Vibrio parahaemolyticus, and Vibrio cholerae were detected using standard conventional culture techniques. Initial E. coli counts in both mussels and oysters were higher than the safety limit of 330 MPN in 100 g tissue. Interestingly, E. coli counts in mussels decreased after 6 h and maintained low numbers after more than 24 h postharvest. Counts in oysters however increased to 1000 MPN in 100 g tissue. V. parahaemolyticus in mussels and oysters showed a gradual increase in counts with increasing holding time albeit in numbers that are lower than the safety limit of 1000 cfu g-1 tissue. Qualitative detection of Salmonella and V. cholerae showed the presence of both pathogens in all the sampling points. All four pathogens were also detected in the culture waters and in the sediment. Results of the study showed that the culture environment and the handling practices contribute greatly to the pathogen contamination in oysters and mussels.

Use of Purple Non-Sulfur Photosynthetic Bacteria (Rhodobacter sphaeroides) in Promoting Ciliated Protozoa Growth.

Photosynthetic bacterium (PSB) was isolated from sediment samples of Yamagawa Bay, Kagoshima, Japan. Phylogenetic analysis results of PSB isolate were closely related to Rhodobacter sphaeroides, purple non-sulfur photosynthetic bacteria (PNSB). Pink-colored smooth edges of single bacterial colonies were observed after 3-5 days of incubation period on Basic I medium agar plates. Rhodobacter sphaeroides microscopic examination showed a short rod cell (1-2 µm length) with round ends. Sediment and water samples used for ciliates cultivation were collected from Kuwano-ura Bay, Koshiki Island, Japan. Ciliates were cultivated using fish meal with radish leaves medium (MI), with sediment into MI (MII) and algae media (MIII). The use of the algae media (MIII) in cultivation mixture produced the highest total number of ciliates. Big size ciliates were identified as Euplotes minuta and Cyclidium varibonneti, while small size was identified as Micrometopion nutans, based on PCR-DGGE. When ciliates were cultured with the PSB isolate, Rhodobacter sphaeroides as a feed, ciliates grow to 2,081 individual ml-1 72 hrs later. These findings indicate that PNSB can be used to promote ciliates growth.

Nectin-2 Expression on Malignant Plasma Cells Is Associated with Better Response to TIGIT Blockade in Multiple Myeloma.

PURPOSE: T-cell immunoreceptor with Ig and ITIM domain (TIGIT) blockade could represent an alternative therapeutic option to release the immune response in patients with multiple myeloma. Here we analyzed the expression of TIGIT and its ligands poliovirus receptor (PVR) and nectin-2 in the bone marrow (BM) of patients with monoclonal gammopathies and the efficacy of TIGIT blockade activating antimyeloma immunity. EXPERIMENTAL DESIGN: Expression levels of TIGIT and its ligands were characterized by flow cytometry and ELISA. TIGIT blockade was analyzed in in vitro functional assays with peripheral T cells. BM cells were studied with NanoString technology, real-time PCR, and ex vivo patient BM cell models. RESULTS: TIGIT and its ligands are highly expressed in the BM of patients with multiple myeloma, suggesting that may play a role in restraining immune activation. TIGIT blockade depleted FoxP3+ Tregs while increasing proliferation of IFNγ-producing CD4+ T cells from patients with multiple myeloma. PVR ligation inhibited CD8+ T-cell signaling and cell proliferation which could be overcome with anti-TIGIT mAb. However, BM cells showed a remarkable heterogeneity in immune signature. Accordingly, functional ex vivo BM assays revealed that only some patients respond to checkpoint blockade. Thus, response to TIGIT blockade correlated with low frequency of TIGIT+ cells and high nectin-2 expression on malignant plasma cells. CONCLUSIONS: TIGIT blockade efficiently reinvigorated peripheral T cells from patients with multiple myeloma. However, in the BM, the efficacy of blocking anti-TIGIT mAb to achieve tumor cell death may depend on the expression of TIGIT and nectin-2, becoming potential predictive biomarkers for identifying patients who may benefit from TIGIT blockade.

Impact of nutritional risk on 28-day mortality and the prevalence of underfeeding in critically ill patients: a prospective cohort study / Impacto del riesgo nutricional sobre la mortalidad al día 28 y prevalencia de subalimentación en pacientes de terapia intensiva: estudio prospectivo de cohorte

INTRODUCTION: nutritional risk is an important prognostic factor in hospitalized patients, but frequently it is underappreciated and not considered as a part of the prognostic evaluation in patients from intensive care units. OBJECTIVE: to evaluate the association between nutritional risk and 28-day mortality and characterize the nutritional support in critically ill patients. METHODS: this was a single-center, prospective cohort study was performed over 7 months in a Medical-surgical ICU of a tertiary hospital in Mexico. From 352 admissions a consecutive sample of 110 patients was included. All of them were ≥ 18 years old, with ≥ 48 h of stay in ICU and with the consent to participate. Nutritional risk assessed by the modified NUTRIC score (mNUTRIC score), 28-day mortality and nutritional support characteristics were recorded. RESULTS: the patient characteristics: mean age 50.7 ± 16.8 years, APACHE II score 15.5 ± 5.8, SOFA score 6.9 ± 3, invasive mechanical ventilation (IMV) 65.5 % and 28-day mortality 23.6 %. High nutritional risk (31.8 %) was associated with 28-day mortality (RR 5.81, 95 % CI 2.69-12.53). In the surviving group, the mNUTRIC score correlated with the length of stay (LOS) in the ICU (r = 0.216, p = 0.049), LOS in the hospital (r = 0.230, p = 0.036) and IMV duration (r = 0.306, p = 0.037). Nutritional support was administered in 55.4 % of the patients, reaching only 52.9 % and 46 % of the energy and protein requirements, respectively. Only 18 % and 21.3 % of the patients achieved the energy and protein requirements, respectively. CONCLUSIONS: high nutritional risk was associated with a higher risk of 28-day mortality. Less than a quarter of the patients receiving nutritional support reached the energy and protein requirements

INTRODUCCIÓN: el riesgo nutricional es un factor pronóstico importante en pacientes hospitalizados, pero frecuentemente es infravalorado y no se considera dentro de la evaluación de los pacientes en unidades de cuidados intensivos. OBJETIVO: evaluar la asociación del riesgo nutricional con la mortalidad al día 28 en pacientes críticos y caracterizar el soporte nutricional. MÉTODOS: se desarrolló un estudio de cohorte prospectivo durante 7 meses en una UCI de tercer nivel en México. Se obtuvo una muestra consecutiva con 110 pacientes de 352 elegibles, con edad ≥ 18 años, estancia ≥ 48 h en UCI, datos completos y consentimiento para participar. El riesgo nutricional fue evaluado con NUTRIC score modificado (mNUTRIC score) y se registró la mortalidad al día 28 y las características del soporte nutricional. RESULTADOS: los pacientes tenían una edad de 50,7 ± 16,8 años; APACHE II, 15,5 ± 5,8; SOFA, 6,9 ± 3; ventilación mecánica invasiva (VMI) en 65,5 % y el 23,6 % de los pacientes falleció al día 28. El alto riesgo nutricional (31,8 %) se asoció con la mortalidad al día 28 (RR 5,81, IC 95 %, 2,69-12,53). En los supervivientes, el mNUTRIC score tuvo correlación con las duraciones de la estancia en UCI (ℓ = 0,216, p = 0,049), estancia hospitalaria (ℓ = 0,230, p = 0,036) y VMI (ℓ = 0,306, p = 0,037). El 55,4 % de los pacientes recibió soporte nutricional. Lograron el 52,9 % y 46 % de las metas energéticas y proteicas, respectivamente. Solo el 18 % alcanzó la meta energética y el 21,3 %, la meta proteica. CONCLUSIONES: los pacientes con alto riesgo nutricional tienen mayor riesgo de morir al día 28. Menos de un cuarto de los pacientes con soporte nutricional alcanzó las metas nutricionales

Impact of nutritional risk on 28-day mortality and the prevalence of underfeeding in critically ill patients: A prospective cohort study.

INTRODUCTION: Introduction: nutritional risk is an important prognostic factor in hospitalized patients, but frequently it is underappreciated and not considered as a part of the prognostic evaluation in patients from intensive care units. Objective: to evaluate the association between nutritional risk and 28-day mortality and characterize the nutritional support in critically ill patients. Methods: this was a single-center, prospective cohort study was performed over 7 months in a Medical-surgical ICU of a tertiary hospital in Mexico. From 352 admissions a consecutive sample of 110 patients was included. All of them were ≥ 18 years old, with ≥ 48 h of stay in ICU and with the consent to participate. Nutritional risk assessed by the modified NUTRIC score (mNUTRIC score), 28-day mortality and nutritional support characteristics were recorded. Results: the patient characteristics: mean age 50.7 ± 16.8 years, APACHE II score 15.5 ± 5.8, SOFA score 6.9 ± 3, invasive mechanical ventilation (IMV) 65.5 % and 28-day mortality 23.6 %. High nutritional risk (31.8 %) was associated with 28-day mortality (RR 5.81, 95 % CI 2.69-12.53). In the surviving group, the mNUTRIC score correlated with the length of stay (LOS) in the ICU (r = 0.216, p = 0.049), LOS in the hospital (r = 0.230, p = 0.036) and IMV duration (r = 0.306, p = 0.037). Nutritional support was administered in 55.4 % of the patients, reaching only 52.9 % and 46 % of the energy and protein requirements, respectively. Only 18 % and 21.3 % of the patients achieved the energy and protein requirements, respectively. Conclusions: high nutritional risk was associated with a higher risk of 28-day mortality. Less than a quarter of the patients receiving nutritional support reached the energy and protein requirements.

INTRODUCCIÓN: Introducción: el riesgo nutricional es un factor pronóstico importante en pacientes hospitalizados, pero frecuentemente es infravalorado y no se considera dentro de la evaluación de los pacientes en unidades de cuidados intensivos. Objetivo: evaluar la asociación del riesgo nutricional con la mortalidad al día 28 en pacientes críticos y caracterizar el soporte nutricional. Métodos: se desarrolló un estudio de cohorte prospectivo durante 7 meses en una UCI de tercer nivel en México. Se obtuvo una muestra consecutiva con 110 pacientes de 352 elegibles, con edad ≥ 18 años, estancia ≥ 48 h en UCI, datos completos y consentimiento para participar. El riesgo nutricional fue evaluado con NUTRIC score modificado (mNUTRIC score) y se registró la mortalidad al día 28 y las características del soporte nutricional. Resultados: los pacientes tenían una edad de 50,7 ± 16,8 años; APACHE II, 15,5 ± 5,8; SOFA, 6,9 ± 3; ventilación mecánica invasiva (VMI) en 65,5 % y el 23,6 % de los pacientes falleció al día 28. El alto riesgo nutricional (31,8 %) se asoció con la mortalidad al día 28 (RR 5,81, IC 95 %, 2,69-12,53). En los supervivientes, el mNUTRIC score tuvo correlación con las duraciones de la estancia en UCI (ℓ = 0,216, p = 0,049), estancia hospitalaria (ℓ = 0,230, p = 0,036) y VMI (ℓ = 0,306, p = 0,037). El 55,4 % de los pacientes recibió soporte nutricional. Lograron el 52,9 % y 46 % de las metas energéticas y proteicas, respectivamente. Solo el 18 % alcanzó la meta energética y el 21,3 %, la meta proteica. Conclusiones: los pacientes con alto riesgo nutricional tienen mayor riesgo de morir al día 28. Menos de un cuarto de los pacientes con soporte nutricional alcanzó las metas nutricionales.

Hydrocarbon Degradation and Bacterial Community Responses During Remediation of Sediment Artificially Contaminated with Heavy Oil.

　Natural biodegradation of heavy oil in the marine environment can be accelerated by the addition of nutrients or seeding of pre-selected microorganisms. In this study, a microcosm experiment was conducted to investigate the effects of inorganic nutrient supplementation (biostimulation) and bacterial consortium amendment (bioaugmentation) on the natural degradative processes of artificially contaminated sediment. Our results revealed that the addition of nutrients had greater effect on remediation than the addition of bacterial cells. Supplementation of inorganic nutrients promoted and sustained the growth of oil-degrading and heterotrophic bacteria throughout the experimental period. Highest reduction in the total petroleum hydrocarbons, and of their components, n-alkanes, polycylic aromatic hydrocarbons (PAHs) and alkyl PAHs, were obtained in the biostimulated microcosms. Changes in the bacterial community were monitored by the PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) method targeting the 16S rDNA gene. Results revealed different responses of the bacterial community to the addition of heavy oil and remediation agents. Shifts in the bacterial communities in the seawater were more dynamic than in the sediment. Results of this study showed that addition of remediation agents significantly enhanced the natural biodegradation of heavy oil in a sediment-seawater microcosm trial.

Synergistic Effect of Photosynthetic Bacteria and Isolated Bacteria in Their Antifungal Activities against Root Rot Fungi.

Antifungal bacteria (AB) in root rot fungus (RRF)-contaminated sweet potato farms were isolated, and seven strains were initially chosen as antagonistic candidates. An antagonistic test by using the mycelial disk placement method revealed that one AB strain by itself could inhibit the RRF growth. This AB strain was identified as Bacillus polyfermenticus based on phylogeny of 16S ribosomal RNA genes. Two AB strains (Bacillus aerophilus) displayed high levels of antifungal activity when paired with photosynthetic bacterial strain A (a purple nonsulfur photosynthetic bacterium Rhodopseudomonas faecalis). The results suggest the possible use of the isolates as agents for the biological control of the RRF infection of agricultural products in fields of cultivation.

Bioremediation of heavily oil-polluted seawater by a bacterial consortium immobilized in cocopeat and rice hull powder.

We examined the effectiveness of cocopeat and rice hull powder obtained from agricultural wastes as biocarriers for an oil-degrading bacterial consortium. Scanning electron microscopy revealed colonization and strong attachment of bacterial cells on the surface of both carriers. Results of a 60-day in vitro seawater bioremediation trial showed significant oil reduction and high cultivable bacterial counts in treatments augmented with the carrier-attached bacterial consortia compared to treatments supplemented with the same consortium in free living and encapsulated forms. Significant degradations in both aliphatic and aromatic fractions were obtained in treatments augmented with carrier-immobilized consortia. The developed immobilized cells showed sustained activities and viabilities during storage for six months. Results of this study demonstrated that inexpensive waste materials can be utilized as biocarriers of an oil-degrading consortium and that immobilization on biocarriers can enhance the bioremediation of oil-contaminated seawater.

Characterization of the bacterial community in the sediment of a brackish lake with oyster aquaculture.

The physicochemical properties and bacterial community in sediments of Lake Shiraishi, a lake with brackish water, were characterized to elucidate the influence of oyster farming and seawater and freshwater inflow. Physicochemical analyses suggested the marine origin of the sediment at the mouth of the lake, while higher organic matter load and the resultant anaerobic, reductive condition of the sediments of the inner part were observed. The bacterial community in the sediments reflects these sediment environments: the bacterial community in the vicinities of oyster farms included sulfate-reducing bacteria (SRB) , although sulfur-oxidizing bacteria (SOB) were found at all the sampling sites. In addition, similarity of the band profiles obtained with 16S ribosomal RNA gene (16S rDNA) -denaturing gradient gel electrophoresis (DGGE) decreased in proportion to the distance from the mouth of the lake to the oyster farms in the inner part. This study was able to characterize the microbial community shift in brackish lake sediments with an oyster aquaculture system through the molecular fingerprinting technique, DGGE, in relation to their physicochemical characteristics.

Effect of magnesium peroxide biostimulation of fish feed-loaded marine sediments on changes in the bacterial community.

The effect of an oxygen-releasing compound (ORC) magnesium peroxide (MgO(2)) on the changes in the bacterial community in organically polluted sediment of aquaculture farms was tested in a microcosm experiment. The sediment, to which fish feed was added, was treated with 1% or 5% MgO(2). The addition of fish feed induced a highly reduced environment with low redox potential, high total sulfides, and abundance of sulfate-reducing bacteria (SRB) . Although the sediment remained highly reduced at 1% MgO(2), there was a significant reduction of total sulfides, increase of redox potential, and resultant reduction of SRB. The bacterial community clearly changed with the treatments according to denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA gene (16S rDNA) . Aerobes disappeared in the fish feed-added sediment, and some SRB emerged in place of these aerobes. On the other hand, the SRB disappeared in the ORC-amended sediment due to its highly oxic condition. This study revealed the bacterial community in the sediments was affected mainly by the redox potential and resultant sulfides produced by SRB, but total organic carbon and nitrogen were not determinants of the microbial population.