Comparison of Cefazolin and Ceftriaxone as Antimicrobial Prophylaxis in Pancreatoduodenectomy with Preoperative Drainage: Incidence of Surgical Site Infection and Susceptibility of Bacteria in Bile.

BACKGROUND: The optimal perioperative antimicrobial agent for preventing surgical site infection (SSI) in pancreatoduodenectomy (PD) with preoperative biliary drainage (PBD) remains unclear. METHODS: We retrospectively reviewed 288 patients who underwent PD after PBD between 2010 and 2020 at our institution. Patients were classified into two groups according to the perioperative antimicrobial agent used (cefazoline [CEZ] group [n = 108] and ceftriaxone [CTRX] group [n = 180]). The incidence of SSI, type of bacteria in intraoperative bile culture (IBC), and antimicrobial susceptibility to prophylactic antimicrobial agents were analyzed. RESULTS: The incidence of incisional SSI was significantly lower in the CTRX group than in the CEZ group (18% vs. 31%, P = 0.021), whereas the incidence of organ/space SSI in the two groups did not differ to a statistically significant extent (35% vs. 44%, P = 0.133). Gram-negative rod (GNR) bacteria in the IBC showed better antimicrobial susceptibility in the CTRX group than in the CEZ group. In multivariate analysis, antimicrobial resistance due to GNR was a significant risk factor for incisional SSI (odds ratio, 3.50; P < 0.001). CONCLUSIONS: CTRX had better antimicrobial coverage than CEZ for GNR cultured from intraoperative bile samples. In addition, CTRX provides better antimicrobial prophylaxis than CEZ against superficial SSI in patients with PD after PBD. TRIAL REGISTRATION NUMBER: This study was not a clinical trial and had no registration numbers.

A nationwide cross-sectional study using a web-based questionnaire survey of the duration of isolation of COVID-19 inpatients with cancer at Japanese cancer centers.

There is no clear consensus regarding the optimal isolation duration for immunocompromised patients with coronavirus disease 2019 (COVID-19). Therefore, we conducted a questionnaire survey at eight Japanese cancer centers to investigate the practices of infectious disease specialists regarding the duration of isolation for COVID-19 inpatients with cancer. For asymptomatic to severely ill COVID-19 inpatients without severe immunodeficiency, four centers reported at least 10 days of isolation without testing, and two reported at least 20 days. Two centers incorporated polymerase chain reaction (PCR) as a criterion for terminating the isolation of inpatients without severe immunodeficiency. For severely immunocompromised COVID-19 inpatients, at least 20 days of isolation were required in seven facilities, regardless of illness severity. Additionally, seven centers had implemented Ct or antigen quantification test values as criteria for de-isolating severely immunocompromised inpatients. No cases caused nosocomial outbreaks after isolation was terminated based on each facility's criteria for isolation termination. Thus, cancer patients required longer isolation periods than the general population in most facilities, and for those with severe immunodeficiency, the isolation periods were longer and more tightly controlled with tests.

Comparison between IMP carbapenemase-producing Enterobacteriaceae and non-carbapenemase-producing Enterobacteriaceae: a multicentre prospective study of the clinical and molecular epidemiology of carbapenem-resistant Enterobacteriaceae.

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) are classified as carbapenemase-producing Enterobacteriaceae (CPE) and non-CPE; the majority of CPE in Japan produce IMP carbapenemase. OBJECTIVES: We evaluated the clinico-epidemiological and microbiological information and effects of IMP-type carbapenemase production in CRE. METHODS: Patients with isolations of CRE (MICs of meropenem ≥2 mg/L, imipenem ≥2 mg/L or cefmetazole ≥64 mg/L) from August 2016 to March 2018 were included. Microbiological analyses and WGS were conducted and clinical parameters were compared between groups. Independent predictors for the isolation of CPE from patients were identified by logistic regression. For comparing clinical outcomes, a stabilized inverse probability weighting method was used to conduct propensity score-adjusted analysis. RESULTS: Ninety isolates (27 CPE and 63 non-CPE) were collected from 88 patients (25 CPE and 63 non-CPE). All CPE tested positive for IMP carbapenemase. Antibiotic resistance (and the presence of resistance genes) was more frequent in the CPE group than in the non-CPE group. Independent predictors for CPE isolation were residence in a nursing home or long-term care facility, longer prior length of hospital stay (LOS), use of a urinary catheter and/or nasogastric tube, dependent functional status and exposure to carbapenem. Although in-hospital and 30 day mortality rates were similar between the two groups, LOS after CRE isolation was longer in the CPE group. CONCLUSIONS: IMP-CPE were associated with prolonged hospital stays and had different clinical and microbiological characteristics compared with non-CPE. Tailored approaches are necessary for the investigational and public health reporting, and clinical and infection prevention perspectives for IMP-CPE and non-CPE.

Neisseria macacae bacteremia: report of two cases with a literature review.

BACKGROUND: Neisseria macacae was discovered in the oral cavity of monkeys in 1983. In humans, it has been isolated from the upper respiratory tract of neutropenic patients. However, only two cases of N. macacae bacteremia have been reported in a 65-year-old man with infective endocarditis and a 5-month-old child with fever and petechiae. There are no reports of infections in cancer patients. Here, we present two cases of N. macacae bacteremia in cancer patients. CASE PRESENTATION: In the first case, a 42-year-old woman who underwent ovarian cancer surgery presented with duodenal invasion associated with multiple lymph node metastasis. N. macacae was isolated from her blood culture and identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). In the second case, a 69-year-old woman with a long-standing history of esophagogastric junction cancer presented with fever. She had stage IVB cancer with lung, bone, and multiple lymph node metastasis. The last chemotherapy was administered 5 weeks before N. macacae was detected using MALDI-TOF MS and nitrate test negative. In both cases, transthoracic echography showed no vegetation. Antibiotics were administered for 14 and 13 days in the first and second cases, respectively. In both cases, fever alleviated on day 4 of antibiotic administration. Both patients were discharged after their conditions improved. CONCLUSIONS: This, to our knowledge, is the first report of N. macacae bacteremia in cancer patients. Both patients, mucosal damage was observed in the upper gastrointestinal tract. Therefore, exclusion diagnosis suggested that bacteremia invasion was caused by mucosal rupture in both cases. Both cases responded well to treatment with ß-lactam antibiotics and improved after 2 weeks. Modifying the treatment based on the source of the infection may shorten the treatment period. Therefore, further research on N. macacae bacteremia is necessary. Immunocompromised patients such as those with cancer are susceptible to mucosal damage by unusual bacterial species such as N. macacae despite not having contact with monkeys.

Relationship between drug formulary and frequently used cephalosporins, macrolides and quinolones in Japanese hospitals.

In Japan, hospitals' pharmaceutical affairs committees freely select the drugs to be purchased depending on the regulations of each hospital. This system poses a risk of the absence of essential drugs or an excess of similar drugs, and may promote inappropriate use of third-generation cephalosporins (3GCs) and quinolones. Against this backdrop, we researched availability of antibacterial agents in Japanese hospitals. We conducted a questionnaire-based study in eastern Shizuoka Prefecture, Japan. Questionnaires were sent to 33 hospitals that had established an interactive regional partnership on infection control. We analyzed the number of available oral cephalosporins, macrolides, and quinolones in each hospital, and the correlation between the number of total available antibacterial agents and the hospital scale and cephalexin availability. Thirty-one hospitals participated in this study. First-generation cephalosporin (1 GC) was available in only 22.5% of them. In all participating hospitals, 3GCs were available, with more than one 3 GC available in 74.2%. Quinolones were available in all hospitals, and more than one quinolone in 67.7%. The numbers of hospital beds and total available antibacterial agents were positively correlated and hospitals that owned cephalexin available also significantly more often owned other available antibacterial agents. 1 GC were available in only a few hospitals, while multiple 3GCs and quinolones were available in most. This situation may lead to excess use of 3GCs or quinolones in Japan. A low number of available drugs was associated with cephalexin unavailability. Outpatient antimicrobial stewardship may focus not only on the quality of medicine, but also on the prescribing environment.

Clinical features of Clostridium bacteremia in cancer patients: A case series review.

Clostridium bacteremia is a well-known cause of infection in patients with gastrointestinal lesions. However, the clinical characteristics of this infection in cancer patients are unclear. We retrospectively reviewed cases of blood cultures positive for Clostridium species between March 1, 2004 and May 30, 2018 at the Shizuoka Cancer Center Hospital. Medical records of 40 patients who met the study criteria were reviewed for age, gender, underlying disease, history of disease, blood culture results, laboratory test results, and radiographic data. The common sources of Clostridium species in these patients were hepatobiliary tract infection and liver abscess (13/40; 32.5%) and bacteremia/enteritis due to gastrointestinal tumor (13/40; 32.5%). All patients had malignancies, with the most common being colorectal cancer (n = 9) followed by pancreatic cancer (n = 8) and gastric cancer (n = 6). The most common species isolated was C. perfringens followed by C. ramnosum. Twenty-five patients (62.5%) had polymicrobial bacteremia with the following organisms isolated from concurrent blood cultures: Escherichia coli (n = 8) and Klebsiella spp. (n = 7). Of these bacteremia cases, 37 had digestive organ lesions such as gastrointestinal malignancy, peritoneal dissemination, or intestinal infiltration. Seventeen patients died, resulting in an overall mortality rate of 42.5% at 30 days. Common cases of Clostridium bacteremia were derived from gastrointestinal lesions, and because Clostridium bacteremia is observed regardless of species, it should be considered necessary to examine gastrointestinal lesions.

Infectious disease specialist consultations in a Japanese cancer center: a retrospective review of 776 cases.

BACKGROUND: Little is known about the impact of infectious disease (ID) consultations on the management of patients with cancer. This study aimed to describe the consultation services provided by ID specialists to all departments in a comprehensive cancer center in Japan. METHODS: We conducted a retrospective review of ID consultations with adult patients at a comprehensive cancer center in Japan from April 2017 to March 2018. RESULTS: During the study period, 776 patients with cancer had an ID consultation. Of these, 414 (53.4%) were hospital inpatients. Reasons for the ID consultation comprised clinical management (n = 481, 62.0%), immunization (n = 272, 35.1%), and infection control (n = 23, 3.0%). Of the 474 ID consultations for diagnostic purposes, the most frequent condition was fever or elevated inflammatory markers of unknown origin (n = 125, 26.4%). The most frequent diagnoses after the diagnostic ID consultation were hepatobiliary infections (n = 97, 22.4%), respiratory infections (n = 89, 20.618.8%), and intra-abdominal infections (n = 71, 16.4%). The commonest reasons for immunization consultations were to prevent seasonal influenza (n = 193, 71.0%) and post-splenectomy vaccination (n = 58, 21.3%). The commonest reasons for infection control consultations were suspected tuberculosis or contact with tuberculosis (n = 11, 47.8%) and herpes zoster infection (shingles) (n = 7, 30.4%). CONCLUSIONS: ID specialists play an important role in the clinical management of patients with cancer. ID physicians who work in cancer centers need to be specialized in treating IDs, diagnosing the causes of fevers of unknown origin, and controlling infection.

[Fungal Infections].

In cancer patients, fungal diseases are rare but remains an important complication. Chemotherapy or surgery procedures are often delayed or postponed in patients with fungal disease which might lead to impaired overall survival. Candida, Aspergillus, Cryptococcus and Pneumocystis jirovecii have accounted for most of yeast and mold infections reported in cancer patients. We have to know each risk factor and clinical picture. Early diagnosis strategies improve cancer outcomes. Recently immune checkpoint inhibitors(ICIs)-anti-PD-1(nivolumab, pembrolizumab), anti-PD-L1(atezolizumab, avelumab), anti- CTLA-4(ipilimumab)-have improved outcomes for several malignancies. Use of these drugs is associated with immunerelated adverse effects, requirement for immunosuppressive therapy. Prolonged immunosuppressive therapies may increase fungal diseases.

Clinical and Molecular Characteristics of Klebsiella pneumoniae Isolates Causing Bloodstream Infections in Japan: Occurrence of Hypervirulent Infections in Health Care.

Although hypervirulent Klebsiella pneumoniae (hvKp) has been associated with severe community-acquired infections that occur among relatively healthy individuals, information about hvKp infections in health care settings remains limited. Here, we systematically analyzed the clinical and molecular characteristics of K. pneumoniae isolates causing bloodstream infections in a cross-sectional study. Clinical characteristics of K. pneumoniae bloodstream infections from hospitals across Japan were analyzed by a review of the medical records. Whole-genome sequencing of the causative isolates was performed. Bacterial species were confirmed and hvKp were identified using whole-genome sequencing data. Clinical characteristics of hvKp infections were compared with those of non-hvKp infections by bivariate analyses. Of 140 cases of K. pneumoniae bloodstream infections, 26 cases (18.6%) were caused by various clones of hvKp defined by the carriage of cardinal virulence genes. Molecular identification revealed that 24 (17.1%) and 14 (10%) cases were caused by Klebsiella variicola and Klebsiella quasipneumoniae, respectively. Patients with hvKp infections had higher proportions of diabetes mellitus (risk ratio [RR], 1.75; 95% confidence interval [CI], 1.05 to 2.94), and their infections had significantly higher propensity to involve pneumonia (RR, 5.85; 95% CI, 1.39 to 24.6), liver abscess (RR, 5.85; 95% CI, 1.39 to 24.6), and disseminated infections (RR, 6.58; 95% CI, 1.16 to 37.4) than infections by other isolates. More than one-half of hvKp infections were health care associated or hospital acquired, and a probable event of health care-associated transmission of hvKp was documented. hvKp isolates, which are significantly associated with severe and disseminated infections, are frequently involved in health care-associated and hospital-acquired infections in Japan.

The low incidence of bacteremia after esophageal endoscopic submucosal dissection (ESD) obviates the need for prophylactic antibiotics in esophageal ESD.

BACKGROUND: Although a high incidence of bacteremia after esophageal endoscopic procedures has been reported, the incidence of bacteremia associated with esophageal endoscopic submucosal dissection (ESD) remains unknown. Therefore, we investigated the incidence of bacteremia associated with esophageal ESD. METHODS: From April 2013 to March 2014, patients who underwent esophageal ESD were enrolled prospectively. Two sets of blood cultures were collected from patients at the following time points: (1) immediately after ESD; (2) the next morning; and (3) when fever ≥38 °C was present after ESD. RESULTS: A total of 424 blood culture sets were collected from 101 patients. Six patients had positive blood cultures immediately after ESD (4 %, 7/202 sets). Another patient had a positive blood culture the next morning (0.5 %, 1/202 sets). Ten patients (10 %) developed a post-ESD fever ≥38 °C, and blood cultures from these patients were all negative (0/20 sets). The seven patients with positive blood cultures had no post-ESD fever or infectious symptoms. Growth of Bacteroides thetaiotaomicron was only observed in one patient (1 %) with positive blood cultures immediately after ESD, and this patient was diagnosed with transient bacteremia. The other six patients were considered to have contaminants in their blood cultures. Thus, the incidence of bacteremia after esophageal ESD was 1 % [95 % confidence interval (CI) 0-5 %]. No patient had infectious symptoms, and none required antibiotics after ESD. CONCLUSIONS: The incidence of bacteremia after esophageal ESD was low and post-ESD fever was not associated with bacteremia. We conclude that use of routine prophylactic antibiotics to patients undergoing esophageal ESD is unnecessary. CLINICAL TRIAL REGISTRY NUMBER: UMIN000012908.

Evaluation of Streptococcus pneumoniae in bile samples: A case series review.

Although Streptococcus pneumoniae is an important pathogen of humans, pneumococcal cholangitis is rare because of the rapid autolysis of S. pneumoniae. The aim of this case series was to review patients with bile cultures positive for S. pneumoniae. This study was a single center retrospective case series review of patients with S. pneumoniae in their bile at a tertiary-care cancer center between September 2002 and August 2015. Subjects consisted of all patients in whom S. pneumoniae was isolated in their bile during the study period. Bile specimens for culture were obtained from biliary drainage procedures such as endoscopic retrograde biliary drainage, endoscopic nasobiliary drainage, and percutaneous transhepatic biliary drainage. There were 20 patients with bile cultures positive for S. pneumoniae during the study period. All patients presented with extrahepatic obstructive jaundice due to hepatopancreatobiliary tumors. Nineteen of 20 patients underwent the placement of plastic intrabiliary tubes. The mean time between the first-time drainage and the positive culture was 26 days (range 0-313 days). Although 12 of 20 patients met our definition of cholangitis, 5 were clinically treated with antibiotics based on a physician's assessment of whether there was a true infection. The present study is the largest case series of patients with S. pneumoniae in their bile. Based on our findings, the isolation of S. pneumoniae from bile may be attributed to the placement of biliary drainage devices.

Paragonimus westermani infection mimicking recurrent lung cancer: A case report.

Herein, we report a case of Paragonimus westermani infection, which required differentiation from recurrent lung cancer. A 66-year old Japanese man with a history of lung cancer who had undergone a lobectomy was referred to our clinic for treatment of cough, sputum, dyspnea, and a right pulmonary nodule. He had previously eaten seafood he visited China. P. westermani infection was confirmed by the presence of antibody against P. westermani antigen in the patient's serum and eggs in his sputum. Eventually, molecular identification by PCR-restriction fragment length polymorphism analysis and sequencing confirmed that the patient was infected with triploid forms of P. westermani.

Inpatient infectious disease consultations requested by surgeons at a comprehensive cancer center.

PURPOSE: The aim of this study was to describe the value of infectious disease specialist consultations for surgeons at comprehensive cancer centers. METHODS: A total of 151 cancer surgery inpatients were retrospectively assessed during a 12-month period. We focused on the characteristics of the infectious disease consultations from surgical departments: the referring surgical divisions, the referral phases, and the reasons for the infectious disease consultations. RESULTS: Three-quarters of all consultation requests were made after the day of surgery. Approximately, 60 % of these requests were made within 30 days after surgery for cancer. The reasons for the infectious disease consultations could be classified into three categories: diagnosis and management (54 %), management of established infections (44 %), and surgical antimicrobial prophylaxis (3 %). The most requested reason for consultations was the diagnosis and management of fever or elevated inflammatory markers of unknown etiology. Among the management of established infections, the antimicrobial management of surgical site infections was most frequently requested. CONCLUSIONS: Many surgeons would prefer infectious disease specialists to assume a more direct role in the care of difficult or perplexing cases (such as fevers of unknown origin) while also maintaining a traditional relationship in which the consultant recommends antimicrobial agents during a perioperative period. Particularly at cancer centers where oncology specialists account for a significant proportion of the providers, the knowledge and skill of infectious disease physicians are valued.

Prognosis of Postoperative Cholangitis Following Pancreaticoduodenectomy: A Single-Centered Retrospective Cohort Study.

Introduction Postoperative cholangitis (POC) after pancreaticoduodenectomy is a serious complication. However, the prognostic factors are unclear. We aimed to investigate the relationships between biliary lesions and prognosis in patients with cholangitis after pancreaticoduodenectomy. Methods We conducted a single-centered retrospective cohort study. The unit of analysis was hospital admissions. We extracted patients who underwent pancreaticoduodenectomy from 2010 to 2018, and have a record of hospitalization of cholangitis from January 2010 to October 2019. We defined the bile duct lesions as the presence of one of the following: biliary stent, intrahepatic bile duct dilatation, intrahepatic bile duct stones, or common bile duct stones on imaging studies. The primary outcome was the treatment failure of POC. We defined the failure as a composite outcome of death within 30 days of initiation of treatment, relapse during treatment, or recurrence of cholangitis. We used logistic regression analysis to examine the association between the presence of bile duct lesions and the occurrence of outcomes. Results Of 154 admissions included in the present study, 120 cases (77.9%) were with bile duct lesions. Bile duct lesions were associated with the treatment failure (crude odds ratio [OR] 2.56, 95% confidence intervals [CI] 1.08 to 6.32; adjusted OR 2.81, 95%CI 1.08 to 7.34). Conclusions Clinicians should follow the patient of POC with bile duct lesions on imaging carefully because of the high risk of treatment failure, especially for recurrence. Further studies are warranted to confirm our results.

To treat or not to treat: Assessing the role of anti-enterococcal therapy for intra-abdominal infections in patients with cancer.

The clinical significance of enterococci in intra-abdominal infections, particularly those caused by multiple organisms, remains unclear. There are no definitive guidelines regarding the use of empiric therapy with antimicrobial agents targeting enterococci. In this study, we evaluated the impact of the initial antimicrobial therapy administration of anti-enterococcal agents on the treatment of intra-abdominal infections in patients with cancer in whom enterococci were isolated from ascitic fluid cultures. This retrospective study was conducted at Shizuoka Cancer Center between January 1, 2014, and December 31, 2020, on all adult patients with cancer with enterococci in their ascitic fluid cultures. The primary outcome was all-cause mortality, and the secondary outcomes were composite outcomes consisting of three components (mortality, recurrence, and treatment failure) and the risk factors associated with all-cause mortality and composite outcomes. In total, 103 patients were included: 61 received treatment covering enterococci, and 42 did not. The mortality rates did not differ significantly between the treated and untreated groups (treated: 8/61 [13.1%]; untreated: 5/42 [11.9%]; p = 1.00). Additionally, no significant difference was observed between the groups in terms of composite outcomes (treated group: 11/61 [18.0%]; untreated group: 9/42 [21.4%]; p = 0.80). Multivariate analysis showed that performance status (PS2-4; p < 0.0001) was an independent risk factor for mortality. The composite outcome was also significantly higher for PS2-4 (p = 0.007). Anti-enterococcal treatment was not associated with mortality or the composite outcome. In patients with cancer and intra-abdominal infections caused by enterococci, anti-enterococcal therapy was not associated with prognosis, whereas PS2 or higher was associated with prognosis. The results of this study suggest that the initial routine administration of anti-enterococcal agents for intra-abdominal infections may not be essential for all patients with cancer. To substantiate these findings, validation by a prospective randomized trial is warranted.

Campylobacter showae bacteremia with cholangitis.

We report a case of Campylobacter showae bacteremia associated with cholangitis. A 71-year-old man with advanced bile duct cancer was admitted to our hospital because of cholangitis with shock, hypoglycemia, and impaired renal function. After replacement of the biliary drainage tube, pus was drained from the tube. Specimens for blood and bile cultures were obtained, and fluid resuscitation and antimicrobial treatment were then begun. Although anaerobic blood culture yielded small curved gram-negative rods, the isolate could not be identified by conventional identification methods. The isolate was identified as C. showae by 16S rRNA gene sequencing analysis. We consider here the pathogenicity of C. showae and the association of C. showae with cholangitis.

Liver abscess caused by Clostridium perfringens after left hepatic trisectionectomy for perihilar cholangiocarcinoma: a case report.

BACKGROUND: Clostridium perfringens sepsis has been reported to have a rapid onset and severe clinical outcome. We herein report a case of C. perfringens sepsis associated with massive intravascular hemolysis after left hepatic trisectionectomy for perihilar cholangiocarcinoma. CASE PRESENTATION: A 72-year-old woman underwent left hepatic trisectionectomy for perihilar cholangiocarcinoma. Her postoperative course was uneventful except for bile leakage. She was discharged on postoperative day (POD) 35. On POD 54, she was readmitted because of abdominal pain with a high fever. Although her vital signs were stable on arrival at the hospital, a laboratory examination showed a severe inflammatory reaction and hemolysis, and she had developed disseminated intravascular coagulation. Abdominal contrast-enhanced computed tomography showed a 70-mm irregular shape and low-density containing air in liver segment 6, which suggested a liver abscess. The abscess was immediately drained of pus containing air. The pus showed multiple Gram-positive bacilli, and two blood cultures showed Gram-positive bacilli and hemolysis. Empirical antibiotic therapy with vancomycin and meropenem was started because C. perfringens was detected from the preoperative bile culture. Four hours after arrival, tachypnea and decreased oxygen saturation were observed. Her general condition deteriorated rapidly with significant hypoglycemia, progressive acidosis, anemia, and thrombocytopenia. Despite rapid drainage and empiric therapy, she died six hours after her arrival. At autopsy, the abscess consisted of coagulation necrosis of liver cells with inflammatory cell infiltration, and clusters of Gram-positive large bacilli were observed in the necrotic debris. C. perfringens was detected in the drainage fluid and blood culture. She was diagnosed with a liver abscess and severe sepsis caused by C. perfringens and treated promptly, but the disease progressed rapidly and led to her death. CONCLUSIONS: Sepsis caused by C. perfringens can progress rapidly and lead to death in a few hours, so prompt treatment is needed. When patients who have undergone highly invasive hepatobiliary-pancreatic surgery show hemolysis and hepatic abscesses with gas, C. perfringens should be considered the most likely bacterium.

Phylogenetic analyses of Chilomastix and Retortamonas species using in vitro excysted flagellates.

In vitro excystation of cysts of microscopically identified Chilomastix mesnili and Retortamonas sp. isolated from Japanese macaques and Retortamonas sp. isolated from small Indian mongooses could be induced using an established protocol for Giardia intestinalis and subsequently by culturing with H2S-rich Robinson's medium supplemented with Desulfovibrio desulfuricans. Excystation usually began 2 h after incubation in Robinson's medium. DNA was isolated from excysted flagellates after 4 h of incubation or from cultured excysted flagellates. Phylogenetic analysis based on their 18S rRNA genes revealed that two isolates of C. mesnili from Japanese macaques belonged to the same cluster as a C. mesnili isolate from humans, whereas a mammalian Retortamonas sp. isolate from a small Indian mongoose belonged to the same cluster as that of an amphibian Retortamonas spp. isolate from a 'poison arrow frog' [sequence identity to AF439347 (94.9%)]. These results suggest that the sequence homology of the 18S rRNA gene of the two C. mesnili isolates from Japanese macaques was similar to that of humans, in addition to the morphological similarity, and Retortamonas sp. infection of the amphibian type in the small Indian mongoose highlighted the possibility of the effect of host feeding habitats.

[The management of catheter related blood stream infection].

Catheter-related bloodstream infection causes severe complications and high mortality. CDC revised the guideline for the prevention of intravascular catheter-related infection in 2011, and various anti-infection devices were introduced. However, the most important deterrents of infection are basic procedures such as hand-hygiene and maximal barrier precautions. I would like to describe the points involving early detection, and its medical treatment and prevention.

[Differential diagnosis of acute diarrhea].

Acute diarrhea is defined as the abrupt onset of abnormally high fluid content in the stool. The differential diagnosis of diarrhea is broad and includes the extra-intestinal and systematic diseases. Regardless of the causative agent, initial therapy should include rehydration. Careful interview and physical examination are helpful in determining the pathogens and choosing the most appropriate therapy. Most cases of acute diarrhea are self-limited, routine empirical treatment is not warranted.