Lunar Age-Dependent Oscillations in Expression of the Genes for Kisspeptin, GnIH, and Their Receptors in the Grass Puffer during the Spawning Season.

Grass puffer is a semilunar-synchronized spawner: spawning occurs on beaches only for several days of spring tide around new moon (lunar age 0) and full moon (lunar age 15) every 2 weeks from spring to early summer. To investigate the role of kisspeptin and gonadotropin-inhibitory hormone (GnIH) in the semilunar-synchronized spawning, lunar age-dependent expression of the genes encoding kisspeptin (kiss2), kisspeptin receptor (kissr2), GnIH (gnih), GnIH receptor (gnihr), gonadotropin-releasing hormone 1 (GnRH1) (gnrh1), and three gonadotropin (GTH) subunits (gpa, fshb, lhb) was examined in the male grass puffer, which was kept in an aquarium under natural light condition in a lunar month during the spawning period. In the brain, both kiss2 and kissr2 showed lunar variations with a peak at lunar age 10, while both gnih and gnihr showed semilunar variations with two peaks at lunar age 0 and 20. On the other hand, gnrh1 showed semilunar variation with two peaks at lunar age 0 and 15. In the pituitary, kiss2, kissr2, gnih, and gnihr showed similar variations to those shown in the brain. The fshb and lhb mRNA levels showed semilunar variations with two peaks at lunar age 0 and 15. The present study shows lunar and semilunar oscillations of kiss2/kissr2 and gnih/gnihr expressions, respectively, with their peaks around spring tide in the brain and pituitary along with the semilunar expressions of gnrh1 and the pituitary GTH subunit genes. These results suggest that the lunar age-dependent expressions of the kisspeptin, GnIH, and their receptor genes may be primarily important in the control of the precisely timed semilunar spawning of the grass puffer.

Aortic rupture following acute aortitis in a patient with head and neck carcinoma treated with nivolumab: a rare but severe immune-related adverse event.

INTRODUCTION: Immune-related adverse events (irAEs) due to immune checkpoint inhibitors may lead to discontinuation and treatment-related death. Acute aortitis is a rare but severe irAE. CASE PRESENTATION: A 67-year-old man with recurrent lower gingival carcinoma received nivolumab therapy. Twenty-three months later, he experienced chest compression, which resulted in syncope. Following a whole-body computed tomography (CT) scanning, which revealed diffuse thickening of the aorta, and systemic assessments of the causes of aortitis, he was diagnosed with acute aortitis due to irAE. Nivolumab discontinuation and oral steroids improved CT findings. However, 11 months after nivolumab discontinuation, he developed an aortic aneurysmal rupture. Endovascular aortic repair rescued him. A durable anti-cancer response was still observed 4 months after the aortic rupture. CONCLUSION: Although severe irAE, such as acute aortitis, occurred, the patient may still achieve a durable response. A broad examination and prompt treatment of irAE can help improve the patient's survival.

Preliminary Evaluation of a Novel Artificial Intelligence-based Prediction Model for Surgical Site Infection in Colon Cancer.

BACKGROUND/AIM: There are few studies on artificial intelligence-based prediction models for colon cancer built using clinicopathological factors. Here, we aimed to perform a preliminary evaluation of a novel artificial intelligence-based prediction model for surgical site infection (SSI) in patients with stage II-III colon cancer. PATIENTS AND METHODS: The medical records of 730 patients who underwent radical surgery for stage II-III colon cancer between 2000 and 2018 at our institute were retrospectively analyzed. Kaplan-Meier curves were used to examine the association between SSI and oncological outcomes (recurrence-free survival time). Next, we used the machine learning software Prediction One to predict SSI. Receiver-operating characteristic curve analysis was used to evaluate the accuracy of the artificial intelligence model. RESULTS: The prognosis in terms of recurrence-free survival time was poor in patients with SSI (p=0.005, 95% confidence interval=4892.061-5525.251). The area under the curve of the artificial intelligence model in predicting SSI was 0.731. CONCLUSION: As SSI is an important prognostic factor associated with oncological outcomes, the prediction of SSI occurrence is important. Based on our preliminary evaluation, the artificial intelligence model for predicting SSI in patients with stage II-III colon cancer was as accurate as the previously reported model derived through conventional statistical analysis.

Prophylactic antimicrobials may not be needed to prevent surgical site infection after skin biopsy: a retrospective study.

BACKGROUND: Two types of skin biopsies are routinely performed in dermatology: excisional and punch biopsies. A punch biopsy is a relatively low-risk procedure for surgical site infections (SSIs) because of the shallow wound depth and short operative time. In Japan, prophylactic antimicrobial agents are often used after skin biopsies due to lack of consensus, and there is no mention of antimicrobial use after skin biopsies in Japanese guidelines. In this study, we investigated whether prophylactic antibiotic use after punch biopsies reduces the risk of SSI development. METHODS: Cases of punch biopsy performed in our dermatology department during a one-year period from April 2018 to March 2019 were included retrospectively. The cases were divided into a group with and another without prophylactic antimicrobial use after biopsy. RESULTS: A total of 75 cases of punch skin biopsy were reviewed. There were no cases of wound infection after punch biopsy in any of the groups. The number of years of experience of the physicians in the group that used antimicrobials was significantly higher than that in the group that did not use antimicrobials (P < 0.0001). CONCLUSIONS: Our result suggests that the incidence of SSI in punch biopsies without prophylaxis seems to be low. However, further research is needed due to the small number of cases in this study.

A Novel Predictive Model for Anastomotic Leakage in Colorectal Cancer Using Auto-artificial Intelligence.

AIM: Anastomotic leakage (AL) in left-sided colorectal cancer is a serious complication, with an incidence rate of 6-18%. We developed a novel predictive model for AL in colorectal surgery with double-stapling technique (DST) anastomosis using auto-artificial intelligence (AI). PATIENTS AND METHODS: A total of 256 patients who underwent curative surgery for left-sided colorectal cancer between 2017 and 2021 were included. In addition to conventional clinicopathological factors, we included the type of circular stapler using DST, conventional double-row circular stapler (DCS) or EEA™ circular stapler with Tri-Staple™ technology, 28 mm Medium/Thick (Covidien, New Haven, CT, USA) which had triple-row circular stapler (TCS) as a covariate. Auto-AI software Prediction One (Sony Network Communications Inc.) was used to predict AL with 5-fold cross validation. Predictive accuracy was assessed using the area under the receiver operating characteristic curve. Prediction One also evaluated the 'importance of variables' (IOV) using a method based on permutation feature importance. RESULTS: The area under the curve of the AI model was 0.766. The type of circular stapler used was the most influential factor contributing to AL (IOV=0.551). CONCLUSION: This auto-AI predictive model demonstrated an improvement in accuracy compared to the conventional model. It was suggested that use of a TCS may contribute to a reduction in the AL rate.

A Novel Prediction Model for Colon Cancer Recurrence Using Auto-artificial Intelligence.

BACKGROUND/AIM: We aimed to develop a novel recurrence prediction model for stage II-III colon cancer using simple auto-artificial intelligence (AI) with improved accuracy compared to conventional statistical models. PATIENTS AND METHODS: A total of 787 patients who had undergone curative surgery for stage II-III colon cancer between 2000 and 2018 were included. Binomial logistic regression analysis was used to calculate the effect of variables on recurrence. The auto-AI software 'Prediction One' (Sony Network Communications Inc.) was used to predict recurrence with the same dataset used for the conventional statical model. Predictive accuracy was assessed by the area under the receiver operating characteristic curve (AUC). RESULTS: The AUC of the multivariate model was 0.719 (95%CI=0.655-0.784), whereas that of the AI model was 0.815, showing a significant improvement. CONCLUSION: This auto-AI prediction model demonstrates improved accuracy compared to the conventional model. It could be constructed by clinical surgeons who are not familiar with AI.

Scrotal Abscess in a Japanese Patient Caused by Prevotella bivia and Streptococcus agalactiae, Successfully Treated with Cefazolin and Amoxicillin: A Case Report.

BACKGROUND: Infections caused by Prevotella bivia, a gram-negative anaerobic bacillus, are rare, with no reported cases in Japan. We present a novel case of scrotal abscess in a Japanese patient co-infected with Prevotella bivia and Streptococcus agalactiae. CASE PRESENTATION: A 41-year-old uncontrolled diabetic man complained of swelling and pain in the scrotum. On examination, computed tomography revealed an abscess of 5-cm diameter in the scrotum. Then, the abscess was incised and drained. He was treated with cefazolin empirically. Prevotella bivia and Streptococcus agalactiae were identified in the pus cultures obtained from the abscess. However, the susceptibility tests for Prevotella bivia could not be submitted. Seven days following admission, the pain reduced, and the drainage slowed. The patient was discharged on day 14 when cefazolin was discontinued and oral amoxicillin (750 mg/day) was started. Amoxicillin was continued until day 42; improvement was confirmed. CONCLUSION: To the best of our knowledge, this case is the first report of Prevotella bivia in Japan. We suggest that cephem antibiotics such as cefazolin may be effective against Prevotella bivia in Japan.

Predictors for readmission due to cellulitis among Japanese patients.

Cellulitis is an infection of the soft tissues of the skin. Some patients are hospitalized multiple times; lymphedema, chronic venous insufficiency, peripheral circulatory disturbance, and deep vein thrombosis are said to be risk factors for multiple admissions. Conversely, in Japan, elderly women and undernourished elderly have been reported to be at risk of multiple hospitalizations, suggesting a different patient background from that reported overseas. We investigated the characteristics of readmission cases for patients hospitalized for cellulitis in Japan. We retrospectively examined cases of cellulitis and erysipelas admitted between April 1, 2005 and March 31, 2018. Patients with cellulitis or erysipelas at multiple sites and those with osteomyelitis, pressure ulcer infection, and necrotizing fasciitis were excluded. In terms of recurrence, only hospitalizations for recurrence at the same site were considered. Patients with multiple hospitalizations had significantly lower blood albumin levels than those hospitalized only once. Furthermore, the rates of lymphedema, hypertension, and hyperlipidemia were significantly higher in patients hospitalized multiple times. Other laboratory and clinical factors were not statistically significant. Therefore, hypoalbuminemia with or without liver dysfunction, lymphedema, hypertension, and hyperlipidemia were suggested as risk factors for cellulitis recurrence. However, chronic venous insufficiency, peripheral circulatory disturbance, and deep vein thrombosis did not seem to be risk factors in Japanese cases. Japanese cases had a low body mass index (approximately 25 kg/m2 ), suggesting that the patient background may be different from that in existing reports. This suggests that the risk factors in Japanese cases may be different from those reported in other countries.

First report of subcutaneous abscess caused by Porphyromonas gingivalis.

Approximately 90% of skin infections are thought to be attributable to Staphylococcus aureus and Streptococcus pyogenes, along with some anaerobic bacteria such as Bacteroides and Prevotella species, which are considered significant causative agents in post-operative skin infections especially in diabetics. Species from the anaerobic Porphyromonas genus are known to cause oral infections, but rarely cause infection of the skin. In this case report, we describe a subcutaneous abscess caused by Porphyromonas gingivalis in a 67-year-old man who had started chemotherapy for lung cancer (cT3N3M0 stage Ⅲ B) three days prior to consulting a dermatologist. On clinical examination, a fist-sized mass with a hot sensation was observed in the left temporal region of the face, and treatment with cefazolin was commenced at 6 g/day. After three days, the mass was drained via skin incision and pus culture was performed, which revealed infection with P. gingivalis. The patient was successfully treated with abscess drainage and antibiotics therapy. We suggest that in tandem with immunosuppression, P. gingivalis could be a cause of skin infections.

Streptococcus pyogenes balanoposthitis.

The main causative organism of balanoposthitis in sexually active adolescents is reportedly the group B hemolytic streptococcus. While cases of balanoposthitis caused by group A streptococcal infection in children have been reported, their occurrence in the adolescent age group is relatively rare. We describe a case of balanoposthitis caused by Streptococcus pyogenes (group A streptococcus) in a 31-year-old man who presented to the hospital with complaints of pain and swelling in his penile foreskin for the past 6 days. The patient was treated successfully by performing a ventral incision on the foreskin and administering effective antimicrobial therapy involving amoxicillin 750 mg/day. Group A beta-hemolytic Streptococcus pyogenes should also be considered a causative organism in the differential diagnosis, while managing a patient with balanoposthitis.

Improved health-related quality of life in patients treated with topical sirolimus for facial angiofibroma associated with tuberous sclerosis complex.

BACKGROUND: Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder forming hamartomas throughout the body. Facial angiofibromas (FAs) occur in 75% of TSC patients, which are often enlarged, impairing the appearance of the face, and reducing the patient's quality of life (QOL). The aim of this study was to characterize the impact of topical sirolimus treatment on the health-related QOL in patients with FA associated with TSC. METHODS: We investigated a total of 33 patients who received sirolimus gel treatment for FA associated with TSC and assessed the changes in the health-related QOL using the Medical Outcomes Study 36-Item Short Form (SF-36) Health Survey. SF-36 surveys were performed before and after 3 months of treatment. The conditions of the patients after using the sirolimus gel were categorized into the following three categories: "improved," "unchanged," and "aggravated." Adverse events were investigated using the CTCAE v5.0-JCOG. RESULTS: The median age of the patients was 25 (range 14-55) years. After 3 months of sirolimus gel treatment, three scale scores of the SF-36, vitality (VT), social function (SF), and mental health (MH), were significantly improved compared to before the treatment. The VT and SF in patients who had improved FA were significantly better than those in the other patients. There were no significant differences in any scale scores between patients with and without adverse events at 3 months after the initiation of sirolimus gel treatment. CONCLUSIONS: This is the first report regarding improved health-related quality of life in patients treated with sirolimus gel for FA associated with TSC by using the SF-36. The three scale scores associated with mental health were significantly improved compared to before the treatment. The health-related QOL in patients receiving sirolimus gel treatment is more strongly affected by the treatment efficacy than adverse events. Sirolimus gel treatment improves the health-related QOL in patients with FA associated with TSC.

Fecal carriage and molecular epidemiologic characteristics of carbapenemase-producing Enterobacterales in primary care hospital in a Japanese city.

BACKGROUND: The worldwide spread of organisms with antimicrobial resistance is of concern, especially the trend of significantly increasing carbapenemase-producing Enterobacterales (CPE). In this study, we investigated the annual trend of intestinal CPE carriage rates in inpatients and healthy adults in a primary care hospital in Tenri, Japan. METHODS: We collected 551 samples of feces from inpatients in our institution and 936 samples from healthy people living in Tenri city from December 2012 to April 2015. All samples were cultured on MacConkey agar plates containing 4 µg/mL ceftazidime for screening test. The colonies grown on the screening medium were detected for carbapenemase genes (blaIMP-1, blaIMP-2, blaVIM, blaKPC, blaGES, blaNDM, and blaOXA-48 groups) by multiplex PCR, and CPE were identified by MALDI-TOF MS. Plasmid replicon typing and pulsed-field gel electrophoresis (PFGE) were performed on PCR-positive strains. RESULTS: The CPE carriage rate was 1.6% (9/551) in the inpatient group and 0% (0/936) in the healthy adults group. The numbers of strains positive for the carbapenemase gene were 4 for Enterobacter cloacae, 2 for Klebsiella pneumoniae, 1 for Citrobacter freundii, 1 for Raoultella ornithinolytica and 1 for Escherichia coli. In all CPE strains, the carbapenemase gene was blaIMP-6 and the plasmid replicon type was IncN. The 4 E. cloacae strains showed a similar pattern in PFGE. CONCLUSION: In the same city in Japan, CPE intestinal carriers were detected only in the inpatient group in this study but not in a healthy adults, suggesting that the spread of asymptomatic CPE carriers was confined to inpatients.

Postoperative outcomes of gastric carcinoma with lymphoid stroma.

BACKGROUND: Gastric carcinoma with lymphoid stroma (GCLS) is a rare subtype of gastric cancer. There have been several reports demonstrating the favorable prognosis of early GCLS without lymph node metastasis (LNM) compared with gastric adenocarcinomas. However, it remains unknown whether advanced GCLS (AGCLS) with LNM has a similar prognosis and clinicopathological features. This study aimed to assess the clinicopathological features of GCLS of all stages. METHODS: We retrospectively assessed 375 patients who were pathologically diagnosed with gastric cancer and underwent curative surgical resection at Tokyo Medical University, Japan, between September 2013 and October 2019. Of these patients, 357 (95.2%) patients were pathologically diagnosed with gastric adenocarcinomas, and 18 (4.8%) patients were diagnosed with GCLS. The GCLS patients (n = 18) were compared with the gastric adenocarcinoma patients (non-GCLS patients, control) (n = 357) in terms of their clinicopathological features and clinical outcome. RESULTS: The GCLS patients showed significantly predominant upper gastric locations (P = 0.003), lower number of LNM (P = 0.01), and better overall survival rate than the non-GCLS patients (P = 0.029). The predominant upper gastric locations (P = 0.0002), lower number of LNM (P = 0.003), and better overall survival rate (P = 0.04) were significantly correlated in the AGCLS with LNM patients compared with the advanced non-GCLS with LNM patients. For survival analyses, surgical procedure, tumor location, and numbers of positive LNM were adjusted by 1:1 propensity score matching. After adjustment, the overall survival rate was significantly higher in the AGCLS group than in the advanced non-GCLS group (P = 0.03). CONCLUSION: AGCLS has distinct clinicopathological features and clinical behavior that are similar to those of early GCLS. AGCLS with LNM patients showed a significantly lower number of LNM and a better survival rate than advanced non-GCLS with LNM patients. To our knowledge, this study is the first report to describe the clinicopathological features of AGCLS.

Prediction of Uropathogens by Flow Cytometry and Dip-stick Test Results of Urine Through Multivariable Logistic Regression Analysis.

PURPOSE: Multidrug-resistant Enterobacteriaceae in urinary tract infection (UTI) has spread worldwide; one cause is overuse of broad-spectrum antimicrobial agents such as fluoroquinolone antibacterials. To improve antimicrobial agent administration, this study aimed to calculate a probability prediction formula to predict the organism strain causing UTI in real time from dip-stick testing and flow cytometry. METHODOLOGY: We examined 372 outpatient spot urine samples with observed pyuria and bacteriuria using dip-stick testing and flow cytometry. We performed multiple logistic-regression analysis on the basis of 11 measurement items and BACT scattergram analysis with age and sex as explanatory variables and each strain as the response variable and calculated a probability prediction formula. RESULTS: The best prediction formula for discrimination of the bacilli group and cocci or polymicrobial group was a model with 5 explanatory variables that included percentage of scattergram dots in an angular area of 0-25° (P<0.001), sex (P<0.001), nitrite (P = 0.002), and ketones (P = 0.133). For a predicted cut-off value of Y = 0.395, sensitivity was 0.867 and specificity was 0.775 (cross-validation group: sensitivity = 0.840, specificity = 0.760). The best prediction formula for P. mirabilis and other bacilli was a model with percentage of scattergram dots in an angular area of 0-20° (P<0.001) and nitrite (P = 0.090). For a predicted cut-off value of Y = 0.064, sensitivity was 0.889 and specificity was 0.788 (cross-validation group: sensitivity = 1.000, specificity = 0.766). CONCLUSION: Simultaneous use of the calculated probability prediction formula with urinalysis results facilitates real-time prediction of organisms causing UTI, thus providing helpful information for empiric therapy.

Maternal green tea extract intake during lactation attenuates hepatic lipid accumulation in adult male rats exposed to a continuous high-fat diet from the foetal period.

BACKGROUND: Maternal lipid intake in the early postnatal period has a long-term effect on the possibility of fatty liver formation in children; besides, the importance of lipid consumption during lactation for children's health has been suggested. Green tea extract (GTE) contains abundant catechins, and it has been reported to improve lipid metabolism and prevent fatty liver. OBJECTIVE: The aim of this study was to examine the effects of maternal GTE intake during lactation on hepatic lipid accumulation in adult male rats exposed to a continuous high-fat (HF) diet from the foetal period. METHODS: Pregnant Wistar rats received diets containing 13% (control-fat, CON) or 45% (high-fat, HF) fat. CON-fed mothers received the same diet during lactation, whereas HF-fed mothers received either HF diet alone or HF diet supplemented with 0.24% GTE. At weaning, male offspring were divided into three groups, i.e. CON/CON/CON, HF/HF/HF (HF-offspring) or HF/HF+GTE/HF (GTE-offspring), and were fed until 51 weeks. RESULTS: A significant hepatic triglyceride (Tg) accumulation was observed in the HF-offspring when compared with the other offspring. This is presumed to be caused by the promotion of Tg synthesis derived from exogenous fatty acid due to a significant increase in diacylglycerol O-acyltransferase 1 and a decrease in Tg expenditure caused by decreasing microsomal triglyceride transfer protein (MTTP) and long-chain acyl-CoA dehydrogenase. On the other hand, attenuated hepatic Tg accumulation was observed in the GTE-offspring. The levels of the hepatic lipid metabolism-related enzymes were improved to the same level as the CON-offspring, and particularly, MTTP was significantly increased as compared with the HF-offspring. CONCLUSION: This study indicates the potential protective effects of maternal GTE intake during lactation on HF diet-induced hepatic lipid accumulation in adult male rat offspring and the possible underlying mechanisms.

[Long-Term Recurrence-Free Survival in a Patient Who Received Chemotherapy for Multiple Metastases of Rectal Cancer Including the Lesser-Curvature Lymph Node Metastasis-A Case Report].

A 49-year-old man was preoperatively diagnosed with rectosigmoid carcinoma, c-T4a, N3, M1b, Stage Ⅳb. On CT, lymph node swelling outside that area, including lesser-curvature lymph nodes(LNS), and liver metastases were seen. Laparoscopic high anterior resection was performed with the aim of local control. Additionally, D3 dissection and LNS sampling were performed. The tumor had invaded the bladder wall, and removed LNS were positive for metastasis. The final diagnosis was f-T4b, N3, M1b, Stage Ⅳb. One month after surgery, a CV port was implanted, and chemotherapy was initiated for unresectable cancer. The regimen was capecitabine and oxaliplatin(CAPOX)plus bevacizumab(BEV). After 5 courses, the patient was hospitalized for a CV thrombus that had occurred, and his chemotherapy was withdrawn for approximately 1 month while he was receiving antithrombotic therapy. After discharge, BEV was discontinued, and he received CAPOX alone. Bleeding from a pituitary adenoma was seen after a total of 19 courses. He was hospitalized for 2 months for the treatment, including surgery. A clinical complete response was determined based on CT and PET-CT performed after chemotherapy had been withdrawn for approximately 3 months. For approximately 1 year since the chemotherapy was discontinued, progression-free survival has been maintained.

[Preoperative Therapy for Advanced Lower Rectal Cancer in Our Department].

PURPOSE: This study was aimed at evaluating the oncologic outcomes of our preoperative treatment strategies for cStage Ⅱ/Ⅲ lower rectal cancer. At our hospital, neoadjuvant chemotherapy is administered for patients with bulky mesenteric lymph nodes on pretreatment imaging, and neoadjuvant chemoradiotherapy is administered for patients whose circumferential radial or distal margin cannot be secured because of strong local extension. METHODS: Thirty patients who underwent preoperative therapy followed by total mesorectal excision for cStage Ⅱ/Ⅲ lower rectal cancer were retrospectively analyzed from October 2010 to October 2015. RESULTS: Twenty-five patients underwent neoadjuvant chemotherapy, and 5 patients underwent neoadjuvant chemotherapy. Tumor recurrence occurred in 10 patients at local(5 patients)and distant(5 patients)sites. The 5-year recurrence-free survival(5RFS)was 63.9%. CONCLUSION: We performed preoperative therapy in poor-risk locally advanced lower rectal cancer and obtained good results.

Identification of specific protein amino acid substitutions of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli ST131: a proteomics approach using mass spectrometry.

The global pandemic of ESBL-producing Escherichia coli is associated with sequence type 131 (ST131). However, mechanisms of ST131 spread remain unclear. This study searched for proteins with amino acid substitutions specific for ST131 and used proteomics analysis to clarify ST131 characteristics. Five proteins had ST131-specific amino acid substitutions: uncharacterized protein YahO with E34A (m/z 7655); UPF0337 protein YjbJ with V59D, D60S and T63K (m/z 8351); uncharacterized protein YnfD with S106T (m/z 8448); and acid stress chaperone HdeA with Q92K and N94S (m/z 9714). Soluble cytochrome b562 (m/z 11783) showed seven amino acid substitutions, and the sequence differed between clade C of the pandemic clade and non-C. In silico analysis showed YahO protein-protein interaction with YjbJ, possibly related to biofilm formation. Although the function of soluble cytochrome b562 is electron transport of unknown function, its involvement in biofilm formation was predicted. HdeA was a gastric acid resistance-related protein. The function of YnfD was completely unclear. In conclusion, ST131-specific protein amino acid substitutions consisted mainly of a gastric acid resistance protein and proteins of unknown function (possibly involved in biofilm formation), which might be mechanisms for long-term colonization in the human intestinal tract.