A Lytic Bacteriophage for Controlling Pseudomonas lactis in Raw Cow's Milk.

The control of bacterial growth during milk processing is crucial for the quality maintenance of commercial milk and milk products. During a period of cold storage prior to heat treatments, some psychrotrophic bacteria grow and produce extracellular heat-resistant lipases and proteases that cause product defects. The use of lytic bacteriophages (phages) that infect and kill bacteria could be a useful tool for suppressing bacterial growth during this cold storage phase. In this study, we isolated a Pseudomonas lactis strain and a phage from raw cow's milk. Quantitative characterization of the phage was used to elucidate whether this phage was active under low temperatures and neutral pH and whether it was inactivated during pasteurization. Phage titer determination was possible under conditions ranging from pH 4 to 9 and from 3°C to 25°C; the phage was inactivated under pasteurization conditions at 63°C for 30 min. Furthermore, we showed that this phage reduced viable bacterial cell counts in both skim and whole milk. The results of this study represent the potential uses of phages for controlling psychrotrophic bacterial growth in raw cow's milk during cold storage.IMPORTANCE Suppression of bacterial growth in raw milk under cold storage is crucial for the quality control of commercially supplied milk. The use of lytic phages as low-cost microbicides is an attractive prospect. Due to strict host specificities, phages must be isolated from the raw milk where the host bacteria are growing. We first isolated the P. lactis bacterial strain and then the phage infecting that strain. Partial phage genomic analysis showed that this is a newly isolated phage, different from any previously reported. This study reports a lytic phage for P. lactis, and we have presented evidence here that this phage reduced viable bacterial cell counts not only in rich medium but also in skim and whole milk. As a result, we have concluded that the phage reported in this study would be useful in milk processing.

Evaluation of the Validity of a Novel CKD Assessment Checklist Used in the Frontier of Renal Outcome Modifications in Japan Study.

OBJECTIVE: This study aimed to assess the validity of a novel chronic kidney disease (CKD) evaluation checklist method used in the Frontier of Renal Outcome Modifications in Japan study. METHODS: Nineteen patients with CKD were recruited, and each patient was assessed by 2 dietitians using the checklist and provided with lifestyle modification instructions based on their assessment. We evaluated the concordance between dietitians, and we assessed the accuracy of the protein and salt intake estimates made by dietitians who only had access to patients' food diaries and verbal reports through comparison with assessments made by an independent dietitian who additionally had access to patients' meal photographs and urine collections. RESULTS: The most frequently given instructions concerned blood pressure control (46%), followed by body mass index control (28%), and potassium control (9%). The instructions provided to patients corresponded between dietitians at rates of 94% for patients' 1st evaluation and 74% for their 2nd evaluation. The evaluated items showed good agreement between dietitians except for their estimates of salt and protein intakes. The dietitians categorized salt and protein intakes into 3 groups each (<6, 6-12, and >12 g and <0.8, 0.8-1.2, and >1.2 g/kg, respectively). The concordance rates between dietitians were 77.1% and 80.8%, and Cohen's κ coefficients were 0.633 and 0.613 for salt and protein intakes, respectively. The concordance rates between the dietitians' estimates and the independent dietitian's objective assessment were 78.5% and 45.1%, and Cohen's κ coefficients were 0.616 and 0.311 for salt and protein intakes, respectively. The estimates and objective assessments were strongly correlated for salt intake, but weakly correlated for protein intake. CONCLUSION: We concluded that the checklist method was appropriate for the evaluation of CKD patients except for protein intake estimation. We hope it will be useful for the instruction of CKD patients widely in the future.

Serum YKL-40 Level is Associated with Geriatric Nutritional Risk Index (GNRI) and γ-GTP in Hemodialysis Patients.

Chitinase-3-like protein 1 (YKL-40) is a glycoprotein associated with inflammation and tissue remodeling that has recently been used as a marker of inflammation in hemodialysis (HD) patients. In this study, we aimed to determine whether YKL-40 has potential to serve as a nutritional parameter in Japanese HD patients. The serum YKL-40 concentration, hematological parameters, inflammatory marker levels, anthropometric measurements, and laboratory values were measured in 88 patients receiving HD. The geriatric nutritional risk index (GNRI) was used as a nutritional assessment tool. 45.4% of patients were malnourished. YKL-40 correlated positively with age, alkaline phosphatase, alanine transaminase and γ-glutamyl transpeptidase (γ-GTP) levels, but not with nutritional status, and correlated inversely with ankle brachial index score, a predictor of atherosclerosis. Furthermore, multiple regression analysis confirmed that γ-GTP, GNRI and age correlated with YKL-40. YKL-40 elevation was associated with γ-GTP, GNRI and age in HD patients. J. Med. Invest. 69 : 101-106, February, 2022.

Simplified nutritional screening tools for patients on maintenance hemodialysis.

BACKGROUND: Malnutrition is a prevalent complication in patients on maintenance hemodialysis. Nutritional screening tools may be useful to identify those patients at nutritional risk from among hundreds of hemodialysis patients in a large facility. OBJECTIVE: We tested several simplified nutritional screening tools on hemodialysis patients to validate the potential application of the tools. DESIGN: The simplified nutritional screening tools were chosen from references published between 1985 and 2005. Nutritional assessments, including history taking, and anthropometric and biochemical measurements were performed on 422 hemodialysis patients. These results were applied to obtain the score of each nutritional screening tool and the malnutrition-inflammation score (MIS), a comprehensive nutritional assessment tool, as the reference standard. The usefulness of each nutritional screening tool for identifying nutritional risk was assessed by comparison with the MIS value and various individual nutritional measures. RESULTS: Five reliable nutritional screening tools were found by the literature search. Among them, the geriatric nutritional risk index (GNRI) was considered to be the most accurate in identifying hemodialysis patients at nutritional risk, because the area under the receiver operating characteristic curve generated with the MIS value was the largest. The GNRI showed a significantly negative correlation with the MIS (r=-0.67, P<0.0001), and the most accurate GNRI cutoff to identify a malnourished patient according to the MIS was <91.2. The GNRI's sensitivity, specificity, and accuracy of <91.2 in predicting malnutrition according to the MIS were 0.730, 0.819, and 0.787, respectively. CONCLUSION: The GNRI was the simplest and most accurate risk index for identifying hemodialysis patients at nutritional risk according to the MIS.