Posterior wall thickness of the confluent inferior pulmonary veins measured by left atrial intracardiac echocardiography: implications for catheter ablation.

BACKGROUND: Confluent inferior pulmonary veins (CIPV) is a rare anatomical variant. There is few evidence in the literature regarding anatomic landmarks consideration to guide radiofrequency application in avoiding complications in the esophagus in CIPV cases. METHODS: Of 986 consecutive patients undergoing atrial fibrillation (AF) ablation from July 2020 to June 2022, seven (0.7%) had CIPV with a common trunk connecting to the LA diagnosed by 3-dimensional contrast-enhanced computed tomography. Using intracardiac echocardiography (ICE) performed from the left atrium (LA), we measured the posterior wall thickness (PWT) of the CIPV adjacent to the esophagus and compared the measurement with the LA posterior wall thickness (LAPWT) at the left inferior PV level of 25 controls without CIPV. For ablation in CIPV patients, each superior PV was individually isolated, and box isolation of CIPV without ablating the CIPV posterior wall was added (tri-circle ablation technique). RESULTS: The CIPV PWT was 0.7 ± 0.1 mm, while non-CIPV LAPWT was 2.0 ± 0.4 mm (P < 0.001). In the CIPV group, upper and lower portions of the CIPV were both apart from the esophagus (mean distances, 6.7 ± 3.4 mm and 7.9 ± 2.7 mm, respectively). Individual superior PV isolation and box CIPV isolation resulted in complete isolation of all PVs, with no complications. All CIPV patients except one remained AF recurrence-free for 376 ± 52 days. CONCLUSIONS: Although CIPV frequency is low, CIPV PWT is very thin and special care is needed during ablation. A "tri-circle" ablation strategy avoids ablating in the thinnest portion of the posterior wall. Further studies are warranted to assess the safety.

Reducing the urine collection rate could prevent hospital-acquired horizontal transmission of multidrug-resistant Pseudomonasaeruginosa.

INTRODUCTION: Multidrug-resistant Pseudomonas aeruginosa (MDRP) is a waterborne pathogen that occasionally causes hospital-acquired infection in immunocompromised or critically ill patients. Urine is frequently collected to evaluate renal function or to perform hormonal examinations, but the procedure involves risk due to the possibility of healthcare workers with contaminated hands. Our objective was to evaluate the association between the urine collection and hospital-acquired horizontal transmission of MDRP. METHODS: We monitored the urine collection rate from 2011 to 2017, as part of ongoing efforts to reduce the need to collect urine. The urine collection rate and the frequency of isolation of MDRP, Methicillin resistant S. aureus (MRSA) and extended spectrum ß-lactamases (ESBL)-producing E. coli were analyzed during the same period. PFGE and MLST were also performed to analyze the identity of 5 MDRP strains detected on the same ward in 2014-2015. RESULTS: The urine collection rate was dramatically decreased from 4.8% in 2011 to less than 0.5% in 2017, because the isolation rate of MDRP was significantly positively associated (RR = 1.72, 95%CI:1.03-2.85) with the urine collection rate. Isolations of MRSA and ESBL-producing E. coli showed no significant. Molecular typing showed the PFGE patterns of 3 of 5 MDRP strains were closely related as did MLST (ST17), and the remaining 2 MDRP strains had different PFGE and MLST patterns (ST14, ST655). Our data implicated the urine collection as one of the causes of hospital-acquired MDRP infections. CONCLUSIONS: We concluded that a reducing the urine collection rate could contribute to preventing hospital-acquired horizontal transmission of MDRP.

Infection Control for a Carbapenem-Resistant Enterobacteriaceae Outbreak in an Advanced Emergency Medical Services Center.

BACKGROUND: A carbapenem-resistant Enterobacteriaceae (CRE) outbreak occurred in an advanced emergency medical service center [hereafter referred to as the intensive care unit (ICU)] between 2016 and 2017. AIM: Our objective was to evaluate the infection control measures for CRE outbreaks. METHODS: CRE strains were detected in 16 inpatients located at multiple sites. Environmental cultures were performed and CRE strains were detected in 3 of 38 sites tested. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and detection of ß-lactamase genes were performed against 25 CRE strains. FINDINGS: Molecular typing showed the PFGE patterns of two of four Klebsiella pneumoniae strains were closely related and the same MLST (ST2388), and four of five Enterobacter cloacae strains were closely related and same MLST (ST252). Twenty-three of 25 CRE strains harbored the IMP-1 ß-lactamase gene and 15 of 23 CRE strains possessed IncFIIA replicon regions. Despite interventions by the infection control team, new inpatients with the CRE strain continued to appear. Therefore, the ICU was partially closed and the inpatients with CRE were isolated, and the ICU staff was divided into two groups between inpatients with CRE and non-CRE strains to avoid cross-contamination. Although the occurrence of new cases dissipated quickly after the partial closure, a few months were required to eradicate the CRE outbreak. CONCLUSION: Our data suggest that the various and combined measures that were used for infection control were essential in stopping this CRE outbreak. In particular, partial closure to isolate the ICU and division of the ICU staff were effective.

[Combinatorial Vancomycin and Piperacillin/Tazobactam Results in Elevated Vancomycin Trough Concentration and Acute Kidney Injury: A Case Report].

In the hospital, antibiotics are widely used to treat infections. We report a case of acute kidney injury (AKI) caused by an antibiotic drug combination. A 30-year-old Japanese male presented with lung metastases, pneumothorax, empyema, and methicillin-resistant Staphylococcus aureus (MRSA) infection. The patient received a combination of vancomycin and piperacillin/tazobactam, which resulted in elevated vancomycin trough concentration and subsequently in AKI. Renal function was restored upon vancomycin and piperacillin/tazobactam cessation. Though this patient had AKI most likely due to the combined use of two agents as has been reported in many cases, vancomycin trough concentration showed an unexpected abnormal increase when halting vancomycin treatment. This is the first report indicating a drug-drug interaction between vancomycin and piperacillin/tazobactam with unexpected abnormal vancomycin trough concentration, leading to AKI, additionally we think that there was a situation that he stressed against the kidney by a history of medications caused renal dysfunction and co-administration. We suggest that when using vancomycin in combination with piperacillin/tazobactam, the trough concentration of vancomycin must be confirmed simultaneously with renal function and evaluation, and that the combination of these two drugs should be minimized.

Biofilm-Forming by Carbapenem Resistant Enterobacteriaceae May Contribute to the Blood Stream Infection.

Bloodstream infection (BSI) due to carbapenem-resistant Enterobacteriaceae (CRE) has a high mortality rate and is a serious threat worldwide. Ten CRE strains (eight Enterobacter cloacae, one Klebsiella pneumoniae and one Citrobacter freundii) were isolated from the blood of nine patients, a percentage of whom had been treated with indwelling devices. The steps taken to establish cause included minimum inhibitory concentration (MIC) tests, a pulsed-field gel electrophoresis (PFGE), biofilm study, a multiplex PCR for resistant genes of carbapenemases and extended-spectrum beta-lactamases (ESBLs), and plasmid incompatibility typing. All strains showed a tendency toward resistance to multiple antibiotics, including carbapenems. Frequently isolated genes of ESBLs and carbapenemases include blaTEM-1 (four strains), blaSHV-12 (four strains) and blaIMP-1 (six strains). A molecular analysis by PFGE was used to divide the XbaI-digested genomic DNAs of 10 CRE strains into eight patterns, and the analysis showed that three E. cloacae strains detected from two patients were either identical or closely related. The biofilm production of all CRE strains was examined using a microtiter biofilm assay, and biofilm growth in continuous flow chambers was observed via the use of a confocal laser scanning microscope. Our study indicates that biofilm formation on indwelling devices may pose a risk of BSI due to CRE.

The co-existence of Lemierre's syndrome and Bezold's abscesses due to Streptococcus constellatus: A case report.

RATIONALE: The ancient infectious diseases, Lemierre's Syndrome and Bezold's Abscesses are rare. PATIENT CONCERNS: A 70-year-old Japanese woman with a 15-year history of Parkinson's disease was referred to our hospital due to fever, occipital headache and bilateral shoulder pain that had continued for three months. She had been prescribed prednisolone due to a diagnosis of polymyalgia rheumatica. DIAGNOSES: A blood culture revealed bacteremia of Streptococcus constellatus. In addition, computed tomography revealed Bezold's abscesses and Lemierre's syndrome. INTERVENTIONS: We administered ceftriaxone for 31 days, followed by oral amoxicillin. OUTCOMES: The patient recovered and the abscesses improved. LESSONS: This case underscores the importance of blood culture tests and cross-referencing with radiological imagings in the diagnoses of these rare critical infectious diseases that mimic polymyalgia rheumatica.

Typhoid Vaccination among Japanese Travelers to South Asia and the Factors Associated with Compliance.

Objective In 2010, candid advice concerning the low rate of typhoid vaccination among Japanese travelers was received from Nepal. Recently, progressive Japanese travel clinics have encouraged Japanese travelers to be vaccinated against typhoid fever in conjunction with officially approved vaccines, such as hepatitis A vaccine. We herein report the status of typhoid vaccinations for Japanese travelers to the most endemic area (South Asia) and describe the factors associated with compliance. Methods In the travel clinic at Kurume University Hospital, we used the following criteria to retrospectively extract the records of new pre-travel Japanese clients between January 2011 and March 2015: hepatitis A vaccine administered, traveling to South Asian countries, and ≥2 years of age. We first summarized the participants and then divided them into typhoid-vaccinated and typhoid non-vaccinated groups for a comparative analysis. Results This study included 160 clients. A majority (70.0%) of these clients traveled for business. The duration of trips was long (≥1 month) (75.0%), and India was a popular destination (90.6%). A comparative study between the vaccinated group (n=122) and the non-vaccinated group (n=38) revealed that the two factors most positively associated with typhoid vaccination were business trips [adjusted odds ratio (aOR) 3.59, 95% confidence interval (CI) 1.42-9.06] and coverage by a company/organization payment plan (aOR 7.14, 95% CI 2.67-20.3). Conclusion The trend toward typhoid vaccination among Japanese travelers to South Asia with pre-travel consultation is correlated with business trips and coverage by a company/organization payment plan. If problems concerning the cost of vaccines were resolved, more travelers would request typhoid vaccination.

Disseminated Mycobacterium intracellulare infection with multiple abscesses on extremities in a woman with chronic corticosteroid therapy.

A 78-year-old Japanese woman with rheumatoid arthritis was admitted to our hospital due to fever. She had been prescribed prednisolone and bucillamine. Computed tomography revealed abscesses on extremities. M. intracellulare was cultured from her calcaneus osteomyelitis, and this result pointed to a disseminated mycobacterial infection. We drained the abscesses and found M. intracellulare. We started antimycobacterial agents, but the patient died finally. Disseminated mycobacterial infection is rare but critical, and the possibility of such an infection in an immunocompromised patient should be a prime consideration when choosing appropriate drugs and surgical approaches.

Hepatitis B Vaccination Status among Japanese Travelers.

This study clarified the characteristics of travelers who received hepatitis B vaccinations. Subjects were 233 Japanese travelers who visited our clinic prior to travel. We summarized the characteristics of the clients and performed two comparative studies: first, we compared a hepatitis B-vaccinated group with an unvaccinated group; second, we compared a group that had completed the hepatitis B vaccine series with a group that did not complete the series. The hepatitis B vaccine was administered to 152 clients. Factors positively associated with the hepatitis B vaccination (after adjusting for age and sex) included the following: travel for business or travel as an accompanying family member; travel to Asia; travel for a duration of a month or more; and, inclusion of the vaccine in a company or organization's payment plan. Meanwhile, factors negatively associated with the vaccination were travel for leisure or education, and travel to North America or Africa. Among 89 record-confirmed cases, only 53 completed 3 doses. The completion rate was negatively associated with the scheduled duration of travel if it was from a month to less than a year (after adjusting for age and sex). The present study provides a basis for promoting vaccination compliance more vigorously among Japanese adults.

Mycobacterium conceptionense Bloodstream Infection in a Patient with Advanced Gastric Carcinoma.

A 65-year-old Japanese male farmer with advanced gastric adenocarcinoma and multiple hepatic metastases was admitted to our hospital. Blood culture results were positive on day 5, and Gram-positive rods were detected. According to the results of Ziehl-Neelsen staining and a cultured colony of this bacterium, we suspected a mycobacterial infection. Suspecting a rapidly growing mycobacterium (RGM), we started multidrug therapy with levofloxacin, clarithromycin, and ethambutol, and the patient recovered from the bloodstream infection. Further gene examination (16S rRNA, hsp65, and sodA) revealed an isolate of Mycobacterium conceptionense. M. conceptionense was first identified as an RGM in 2006. Among previous case reports of M. conceptionense infections, bone and soft tissue infections in hosts with a disorder of the normal structure (e.g., surgical sites) were dominant. We report the characteristics of M. conceptionense infection in this first Japanese case report and a review of the literature.

Characteristics of Multidrug-Resistant Corynebacterium spp. Isolated from Blood Cultures of Hospitalized Patients in Japan.

Corynebacterium is a genus consisting of Gram-positive, rod-shaped bacteria, that is wildly distributed in nature. We report the epidemiological characterization of Corynebacterium spp. isolated from blood specimens at the Kurume University Hospital, between June 2008 and November 2011. Twenty-two strains that were likely Corynebacterium spp. were isolated from 22 hospitalized patients, of which 12 (54.5%) were identified as Corynebacterium striatum. Minimum inhibitory concentration tests were performed after biochemical and genotypic identifications. Biofilm production was detected using a 96-well microplate assay. The dissemination of C. striatum was investigated using pulsed-field gel electrophoresis (PFGE). All strains showed the tendency to be resistant to multiple drugs except vancomycin. Fourteen (82.4%) strains, including 9 C. striatum strains were capable of producing biofilms. Four distinct PFGE patterns were detected among C. striatum strains; 6 of which were identified as dominant pattern A (defined in this study) and had high biofilm production ability. During the 3-year monitoring period, these strains might have repeatedly infected the patients or could have readily colonized the hospital environments. C. striatum appeared to be a potential risk factor for bloodstream infections in hospitalized patients. More surveillance and enhanced control strategies are necessary to decrease Corynebacterium spp. infections in hospitals.

An HIV-infected Pregnant Woman Treated with the Long-term Administration of Antiretroviral Therapy Including Raltegravir.

A 27-year-old HIV-infected pregnant Japanese woman was admitted to our hospital at gestational week 14. The patient's HIV viral load was 71,000 copies/mL, and her CD4 cell count was 147 cells/mm(3). Zidovudine, lamivudine, and lopinavir/ritonavir were administered at gestational week 18. Because the viral load increased to 222,000 copies/mL at the initiation of antiretroviral therapy, we added raltegravir. The decrease in the viral load was satisfactory, and a caesarean delivery was performed. Although the plasma concentration of raltegravir in the neonate was significantly high (2,482 ng/mL), no adverse event was confirmed. There was no evidence of the mother-to-child transmission of HIV.

Post-Travel Consultations in a Regional Hub City Hospital, Japan.

OBJECTIVE: To clarify the characteristics of post-travel consultation services in Japan, particularly in the provinces, we analyzed our post-travel patients in the travel clinic of Kurume University Hospital located in Kurume City (a regional hub City in southwestern Japan). METHODS: Sixty post-travel patients visited our clinic between April 2008 and October 2014 and participated in this study: 55 were Japanese and five were foreign. We summarized and compared the characteristics of the patients after dividing the Japanese participants into long-term travelers (>14 days) and short-term travelers (≤14 days). The foreign travelers were described in a separate analysis. RESULTS: Of the 55 Japanese travelers, the mean age (± standard deviation) was 37.3 ± 16.3 years, and 36 patients (65%) were men. Southeast Asia was the major destination (30/55, 55%), and business was stated as the major reason for travel (16/55, 29%). Post-exposure rabies prophylaxis (16/55, 29%) was the most common purpose for the consultations. There were 34 participants (62%) who were classified as short-term travelers. Fewer of the short-term travelers stated receiving pre-travel consultations compared with long-term travelers (11% vs. 79%, p=0.0002). The five foreign travelers included one dengue fever patient and two malaria patients. CONCLUSION: Most post-travel Japanese patients visited our clinic were short-term travelers who had not received any pre-travel consultation. One of the most common complaints, post-exposure rabies prophylaxis, could have been avoided to some extent by appropriate pre-travel consultations. The results of this study suggest that pre-travel consultations should therefore be encouraged for both long- and short-term travelers.

A Retrospective Analysis of Drug Fever Diagnosed during Infectious Disease Consultation.

OBJECTIVE: To clarify the current situation concerning drug fever (DF) in Japan, we retrospectively analyzed patients undergoing infectious disease consultation at our institution. METHODS: Between April 2014 and May 2015, we extracted the records of DF patients from among 388 patients who had obtained infectious disease consultations in Kurume University Hospital. We reviewed their medical charts and summarized the characteristics of DF. RESULTS: This study included the records of 16 patients. Clinical signs (relative bradycardia, the duration of the drug administration before becoming febrile, and the interval between the discontinuation of a drug and the alleviation of a fever), and laboratory tests (varied white blood cell count, low level of C-reactive protein, and a mild elevation of transaminases) were compatible with those from previous reports. Among the drug-confirmed cases, five involved the use of glycopeptides (vancomycin: 3, teicoplanin: 2), which were considered to be uncommon causes, and the another five cases involved the use of ß-lactams. In addition, the procalcitonin levels were either negative or low (≤0.25 ng/mL) in 10 of the 11 procalcitonin-measured cases. CONCLUSION: Our findings demonstrated that glycopeptides, similar to ß-lactams, may be the origin of DF. Furthermore, procalcitonin may be helpful in the diagnosis of DF, but only in combination with other detailed examinations.

Development of a teicoplanin loading regimen that rapidly achieves target serum concentrations in critically ill patients with severe infections.

We performed high-dose loading (12 mg/kg every 12 h for 48 h; 4 doses total) of teicoplanin (TEIC) in patients with severe methicillin-resistant Staphylococcus aureus (MRSA) infections, with the goal of achieving target serum concentration (TEICc) ≥ 15 mg/l within 48 h of starting administration. The safety and effectiveness of the fixed, early-stage administration method were evaluated across a range of kidney dysfunction severity levels. TEIC high-dose loading was administered to 106 patients with MRSA infection from February 2010 to February 2013. After high-dose loading, maintenance doses based on therapeutic drug monitoring (TDM) of TEICc were administered via 30-min intravenous drips, every 24 h. Subjects were divided into 4 groups based on kidney function and renal replacement therapy (RRT) status for safety and effectiveness evaluation: group 1 (G1) did not undergo RRT and exhibited creatinine clearance (Ccr; ml/min/m(2)) >50, group 2 (G2) exhibited Ccr ≤ 50, group 3 (G3) underwent continuous RRT (CRRT), and group 4 (G4) underwent intermittent RRT (IRRT). TEICc was measured after 24, 48, 72, and 144 h, immediately before TEIC administration. Target TEICc was reached in all groups, and bacteriological effectiveness and utility were high in G1, G2, and G3. The maximum TEICc (≥ 28.0 mg/l) and serum albumin (≤ 1.84 g/dl) were associated with organ toxicity. Fixed high-dose loading of TEIC achieved the target therapeutic range (≥ 15 mg/l) within 48 h of the start of administration regardless of kidney dysfunction, and exhibited sufficient utility.

Potential drug interaction between warfarin and linezolid.

OBJECTIVE: Warfarin is known to interact with many drugs; however, there are currently no descriptions of an interaction with linezolid in the literature. It was recently brought to our attention, however, that several warfarin-medicated patients have experienced an increase in the prothrombin time international normalized ratio (PT-INR) following the administration of linezolid. We therefore performed a retrospective survey in order to investigate the possibility of an interaction between warfarin and linezolid. METHODS: The survey items included age, gender, underlying disease, type of surgery, type of infectious disease, duration of linezolid administration, laboratory values and the dose of warfarin. The PT-INR was observed over time before treatment and at days 4 or 5 and 10, completion and one week after the end of concomitant therapy. Patients The subjects included six patients who were recovering from recent heart-related surgery. RESULTS: The PT-INR increased from 1.62±0.32 before concomitant linezolid administration to 3.00±0.83 at day 4 or 5 after concomitant administration (p<0.01) and significantly decreased from 1.65±0.45 at the completion of the regimen to 1.26±0.1 one week later (p<0.05). With respect to the relationship between the dose of warfarin and the PT-INR in five cases, the PT-INR increased following concomitant linezolid treatment in all cases. CONCLUSION: Although it has been reported that linezolid does not influence the metabolism or protein binding of warfarin, our data showed potential drug interactions between warfarin and linezolid. Our data suggest that PT-INR monitoring after the completion of concomitant warfarin and linezolid therapy is important.

The relationship between biofilm formations and capsule in Haemophilus influenzae.

To evaluate the biofilm formation of non-typeable Haemophilus influenzae (NTHi) and H. influenzae type b (Hib) clinical isolates, we conducted the following study. Serotyping and polymerase chain reaction were performed to identify ß-lactamase-negative ampicillin (ABPC)-susceptible (BLNAS), ß-lactamase-negative ABPC-resistant (BLNAR), TEM-1 type ß-lactamase-producing ABPC-resistant (BLPAR)-NTHi, and Hib. Biofilm formation was investigated by microtiter biofilm assay, as well as visually observation with a scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) in a continuous-flow chamber. As a result, totally 99 strains were investigated, and were classified into 4 groups which were 26 gBLNAS, 22 gBLNAR, 28 gBLPAR-NTHi and 23 Hib strains. The mean OD600 in the microtiter biofilm assay of gBLNAS, gBLNAR, gBLPAR-NTHi, and Hib strains were 0.57, 0.50, 0.34, and 0.08, respectively. NTHi strains were similar in terms of biofilm formations, which were observed by SEM and CLSM. Five Hib strains with the alternated type b cap loci showed significantly increased biofilm production than the other Hib strains. In conclusion, gBLNAS, gBLNAR, and gBLPAR-NTHi strains were more capable to produce biofilms compared to Hib strains. Our data suggested that resistant status may not be a key factor but capsule seemed to play an important role in H. influenzae biofilm formation.

Infection control for a methicillin-resistant Staphylococcus aureus outbreak in an advanced emergency medical service center, as monitored by molecular analysis.

A methicillin-resistant Staphylococcus aureus (MRSA) outbreak occurred in an advanced emergency medical service center between 2010 and 2011. Our objective was to evaluate the status of the MRSA outbreak, as monitored by molecular analysis. Twenty-eight MRSA strains were isolated from blood samples from 11 patients, from other specimens (pharynx, nasal cavity, etc.) from 12 patients, from two environmental samples, and from the skin, middle nasal meatus, and urine of one patient each from other wards. Pulsed-field gel electrophoresis (PFGE) was performed to evaluate horizontal transmission. Molecular typing by PFGE showed that the 28 MRSA strains presented 7 patterns in total, and that 11 of the MRSA strains had the same PGFE pattern. Unselective use of intranasal mupirocin ointment, MRSA monitoring for new inpatients, and prevention of direct or indirect contact infection were performed. However, the number of inpatients with MRSA did not quickly decrease, and additional molecular typing by PFGE showed that 10 of 19 MRSA strains found (5 of 6 from blood, 5 of 13 from other specimens) were the same as those found previously. Lectures and ward rounds were performed repeatedly, and staff participation in ward rounds was suggested. Finally, the number of inpatients with MRSA significantly decreased more than 6 months after the intervention. Although the MRSA outbreak was thought to have ended, follow-up molecular typing by PFGE showed that horizontal transmission persisted. Our data suggest that various combinations of infection control measures are essential when dealing with an MRSA outbreak, and monitoring by molecular analysis using PFGE is useful to identify the status of the outbreak.