Immunobiological effects of lipopolysaccharide derived from Helicobacter pylori and influence of a proton pump inhibitor lansoprazole on human polymorphonuclear leukocytes.

Helicobacter pylori colonizes the human gastric mucosa of more than half of the human population and has a unique lipopolysaccharide (LPS) structure. LPS is the most dominant and suitable pathogen-associated molecular pattern that is detected via pattern recognition receptors. Although the priming effect of H. pylori LPS on reactive oxygen species (ROS) production of PMNs is lower than that of Escherichia coli O111:B4 LPS, LPS released from H. pylori associated with antibiotics eradication therapy may activate PMNs and increase ROS production. In addition, we describe the effects of H. pylori and E. coli O111:B4 LPSs on gene expression and the anti-inflammatory effect of lansoprazole (LPZ) in human polymorphonuclear leukocytes. LPS isolated from H. pylori and E. coli O111:B4 alters toll-like receptor 2 (TLR) and TLR4 expressions similarly. However, LPS from E. coli O111:B4 and H. pylori caused a 1.8-fold and 1.5-fold increase, respectively, in CD14 expression. All LPS subtypes upregulated TNFα and IL6 expression in a concentration-dependent manner. Although E. coli O111:B4 LPS upregulated IL8R mRNA levels, H. pylori LPS did not (≦ 100 ng/mL). Gene expression levels of ITGAM demonstrated no significant change on using both LPSs. These different effects on the gene expression in PMNs may depend on variations in LPS structural modifications related to the acquired immunomodulatory properties of H. pylori LPS. Proton pump inhibitors, i.e., LPZ, are used in combination with antibiotics for the eradication therapy of H. pylori. LPZ and its acid-activated sulphenamide form AG-2000 suppress ROS production of PMNs in a dose-dependent manner. These results suggest that LPZ combination with antibiotics for H. pylori eradication reduces gastric inflammation by suppressing ROS release from PMNs.

Efficacy of Cefiderocol, a Novel Siderophore Cephalosporin, against Multidrug Resistant Acinetobacter baumannii Clinical Isolates in Japan.

Multidrug-resistant Acinetobacter baumannii (MDRAB) is an important pathogen that causes nosocomial infections and is resistant to almost all antibiotics, including carbapenems. Cefiderocol is a novel siderophore cephalosporin active against a broad spectrum of gram-negative bacteria. However, the susceptibility of MDRAB to cefiderocol has not yet been reported in Japan. In this study, we measured the minimum inhibitory concentrations (MICs) of antibiotics including cefiderocol against MDRAB clinical isolates collected during a nosocomial outbreak between 2009 and 2010 at the Teikyo University Hospital in Japan. We found that all 10 MDRAB clinical isolates tested were susceptible to cefiderocol, with an MIC range of 0.12 to 1 µg/mL. All the isolates also exhibited resistance to ampicillin-sulbactam and an intermediate resistance to colistin, whereas nine of them were susceptible to tigecycline. DNA sequencing revealed that all strains harbored an OXA-51-like carbapenemase, a major cause of carbapenem resistance in A. baumannii in Japan. In conclusion, this study showed that the cefiderocol susceptibility of MDRAB clinical isolates in Japan was equivalent to that to colistin or tigecycline, and thus cefiderocol is a potential treatment option for MDRAB infections.

Virological outcomes of various first-line ART regimens in patients harbouring HIV-1 E157Q integrase polymorphism: a multicentre retrospective study.

BACKGROUND: Integrase strand transfer inhibitors (INSTIs) are recommended as first-line ART for people living with HIV (PLWH) in most guidelines. The INSTI-resistance-associated mutation E157Q, a highly prevalent (2%-5%) polymorphism of the HIV-1 (human immunodeficiency virus type 1) integrase gene, has limited data on optimal first-line ART regimens. We assessed the virological outcomes of various first-line ART regimens in PLWH with E157Q in real-world settings. METHODS: A multicentre retrospective observational study was conducted on PLWH who underwent integrase genotypic drug-resistance testing before ART initiation between 2008 and 2019 and were found to have E157Q. Viral suppression (<50 copies/mL) rate at 24 and 48 weeks, time to viral suppression and time to viral rebound (≥100 copies/mL) were compared among the first-line ART regimens. RESULTS: E157Q was detected in 167 (4.1%) of 4043 ART-naïve PLWH. Among them, 144 had available clinical data after ART initiation with a median follow-up of 1888 days. Forty-five started protease inhibitors + 2 NRTIs (PI group), 33 started first-generation INSTI (raltegravir or elvitegravir/cobicistat) + 2 NRTIs (INSTI-1 group), 58 started once-daily second-generation INSTI (dolutegravir or bictegravir) + 2 NRTIs (INSTI-2 group) and eight started other regimens. In the multivariate analysis, the INSTI-2 group showed similar or favourable outcomes compared with the PI group for viral suppression rates, time to viral suppression and time to viral rebound. Two cases in the INSTI-1 group experienced virological failure. CONCLUSIONS: The general guideline recommendation of second-generation INSTI-based first-line ART for most PLWH is also applicable to PLWH harbouring E157Q.

Optimizing Excitation Light for Accurate Rapid Bacterial Species Identification with Autofluorescence.

Rapid identification of bacterial species in patient samples is essential for the treatment of infectious diseases and the economics of health care. In this study, we investigated an algorithm to improve the accuracy of bacterial species identification with fluorescence spectroscopy based on autofluorescence from bacteria, and excitation wavelengths suitable for identification. The diagnostic accuracy of each algorithm for ten bacterial species was verified in a machine learning classifier algorithm. The three machine learning algorithms with the highest diagnostic accuracy, extra tree (ET), logistic regression (LR), and multilayer perceptron (MLP), were used to determine the number and wavelength of excitation wavelengths suitable for the diagnosis of bacterial species. The key excitation wavelengths for the diagnosis of bacterial species were 280 nm, 300 nm, 380 nm, and 480 nm, with 280 nm being the most important. The median diagnostic accuracy was equivalent to that of 200 excitation wavelengths when two excitation wavelengths were used for ET and LR, and three excitation wavelengths for MLP. These results demonstrate that there is an optimum wavelength range of excitation wavelengths required for spectroscopic measurement of bacterial autofluorescence for bacterial species identification, and that measurement of only a few wavelengths in this range is sufficient to achieve sufficient accuracy for diagnosis of bacterial species.

Changes in health and sleep quality after anti-retroviral treatment modification in Japanese people living with HIV.

BACKGROUND: Anti-retroviral treatment (ART) modification for treatment simplification is performed in virologically controlled people living with Human Immunodeficiency Virus (PLWH). However, studies on the impact of these stable treatment modifications on health-related quality of life (HRQoL) measured using patient-reported outcomes (PROs) in clinical practice are scarce; this was the focus of this study. METHODS: PLWH who visited Teikyo University Hospital between October 2019 and March 2021, and whose ART was changed to a newly recommended single-tablet regimen for treatment simplification, were included in the study. HRQoL and sleep quality were evaluated using the Short-Form (SF) 8 and Pittsburgh Sleep Quality Index (PSQI) global score, respectively, at two time points: before and after treatment modification. Comorbidities, duration of Human Immunodeficiency Virus diagnosis, ART initiation, ART regimens, and blood test data before and after treatment were assessed. The SF-8 was used to calculate the physical component summary (PCS) and mental component summary (MCS) scores. RESULTS: Forty-nine patients (all male) were included into the study. There was no change in the PCS score before and after ART modification. The MCS score significantly improved from 48.50 ± 6.56 to 50.76 ± 4.37 (p = 0.0159). Thirteen patients' ARTs were changed to dolutegravir/lamivudine. Their HRQoL and sleep quality changes were further analyzed. Their MCS and PSQI scores had improved significantly. Thirty patients' ARTs were changed to bictegravir/tenofovir alafenamide/emtricitabine; however, there were no significant changes in their HRQoL or PSQI score. CONCLUSION: ART modification for treatment simplification based on PROs may improve the HRQoL of PLWH.

Staphylococcus haemolyticus attenuates the antibacterial effect of teicoplanin via aggregates and biofilms.

OBJECTIVES: This study aimed to determine the inhibitory and bactericidal effects of teicoplanin (TEC) on TEC-susceptible Staphylococcus haemolyticus isolated from a patient with cancer in whom infection persisted despite TEC therapy. We also focused on the biofilm-forming ability of the isolate in vitro. METHODS: S. haemolyticus clinical isolate (strain 1369A) and its control strain, ATCC 29970 were cultured in Luria-Bertani (LB) broth with TEC. The inhibitory and bactericidal effects of TEC on planktonic, adherent, biofilm-dispersed, and biofilm-embedded cells of these strains were analyzed by using a biofilm formation/viability assay kit. The expression of biofilm-related genes was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Biofilm formation was determined by using scanning electron microscopy (SEM). RESULTS: The clinical isolate of S. haemolyticus had enhanced ability to bacterial growth, adherence, aggregation, and biofilm formation, thus the inhibitory and bactericidal effects of TEC on planktonic, adherent, biofilm-dispersed, and biofilm-embedded cells of the isolate were attenuated. Additionally, TEC induced cell aggregation, biofilm formation, and some biofilm-related gene expression of the isolate. CONCLUSION: The clinical isolate of S. haemolyticus is resistant to TEC treatment due to cell aggregation and biofilm formation.

Association of demographics, HCV co-infection, HIV-1 subtypes and genetic clustering with late HIV diagnosis: a retrospective analysis from the Japanese Drug Resistance HIV-1 Surveillance Network.

INTRODUCTION: Late diagnosis of the human immunodeficiency virus (HIV) is a major concern epidemiologically, socially and for national healthcare systems. Although the association of certain demographics with late HIV diagnosis has been reported in several studies, the association of other factors, including clinical and phylogenetic factors, remains unclear. In the present study, we conducted a nationwide analysis to explore the association of demographics, clinical factors, HIV-1 subtypes/circulating recombinant form (CRFs) and genetic clustering with late HIV diagnosis in Japan, where new infections mainly occur among young men who have sex with men (MSM) in urban areas. METHODS: Anonymized data on demographics, clinical factors and HIV genetic sequences from 39.8% of people newly diagnosed with HIV in Japan were collected by the Japanese Drug Resistance HIV-1 Surveillance Network from 2003 to 2019. Factors associated with late HIV diagnosis (defined as HIV diagnosis with a CD4 count <350 cells/µl) were identified using logistic regression. Clusters were identified by HIV-TRACE with a genetic distance threshold of 1.5%. RESULTS: Of the 9422 people newly diagnosed with HIV enrolled in the surveillance network between 2003 and 2019, 7752 individuals with available CD4 count at diagnosis were included. Late HIV diagnosis was observed in 5522 (71.2%) participants. The overall median CD4 count at diagnosis was 221 (IQR: 62-373) cells/µl. Variables independently associated with late HIV diagnosis included age (adjusted odds ratio [aOR] 2.21, 95% CI 1.88-2.59, ≥45 vs. ≤29 years), heterosexual transmission (aOR 1.34, 95% CI 1.11-1.62, vs. MSM), living outside of Tokyo (aOR 1.18, 95% CI 1.05-1.32), hepatitis C virus (HCV) co-infection (aOR 1.42, 95% CI 1.01-1.98) and not belonging to a cluster (aOR 1.30, 95% CI 1.12-1.51). CRF07_BC (aOR 0.34, 95% CI 0.18-0.65, vs. subtype B) was negatively associated with late HIV diagnosis. CONCLUSIONS: In addition to demographic factors, HCV co-infection, HIV-1 subtypes/CRFs and not belonging to a cluster were independently associated with late HIV diagnosis in Japan. These results imply the need for public health programmes aimed at the general population, including but not limited to key populations, to encourage HIV testing.

Urine neutrophil gelatinase-associated lipocalin as a biomarker of adult pyelonephritis.

BACKGROUND: Pyelonephritis is a common infection at any age. Urine neutrophil gelatinase-associated lipocalin (NGAL), a novel biomarker of acute renal failure, is related to pyelonephritis in pediatric patients, although the significance of this urine biomarker in adult patients are not clear. We investigated the relationship between urine NGAL of pyelonephritis and non-pyelonephritis. PATIENTS AND METHODS: We prospectively enrolled adult patients who were hospitalized due to pyelonephritis or non-pyelonephritis. Pyelonephritis was diagnosed in patients with fever and bacteriuria, with no any other infection focuses. Non-pyelonephritis was diagnosed in patients who had fever and another infection focus without bacteriuria. Urine samples were collected on days 0, 3 and 7. Urine NGAL levels were measured by ELISA. RESULTS: There were 35 patients in the pyelonephritis group and 19 patients in the non-pyelonephritis group. Urine NGAL level were significantly higher in the pyelonephritis group than the non-pyelonephritis group on day 0 (median 302 ng/mL vs 25 ng/mL, p = 0.006). The area under the receiver operating characteristic curve of NGAL was 0.78 (p = 0.006). Urine NGAL level had a specificity of 66.7% and sensitivity of 87.0% at the cut-off level of 250 ng/mL for diagnosing pyelonephritis. CONCLUSIONS: Urine NGAL level at the diagnosis of infection are elevated in adult patients with pyelonephritis, but not in those with non-pyelonephritis. Urine NGAL might be a supportive biomarker for the diagnosis of pyelonephritis.

Enterococcus casseliflavus Infection: A Review of Clinical Features and Treatment.

Some Enterococcus species, including Enterococcus faecalis and E. faecium, are increasingly becoming a common cause of nosocomial infections, accounting for the majority of human enterococcal infections, while other species, such as E. casseliflavus, have also been shown to be pathogenic to humans due to the increase in immunocompromised patients. These infections vary widely in their mode of transmission, symptoms, and other characteristics. Treatment is difficult in some cases because enterococci are resistant to numerous antimicrobial agents. Enterococcus faecalis and E. faecium are the best-known opportunistic pathogens, but others, including E. casseliflavus, occasionally cause opportunistic infections. This review summarizes the clinical features of E. casseliflavus infections and discusses effective therapeutic strategies. Bacteremia was the most common form of E. casseliflavus infections. Because E. casseliflavus carries the VanC gene, which confers resistance to vancomycin, less resistant drugs such as ampicillin were found more effective in treating the bacteremia. The second most common form of E. casseliflavus infection was trauma-induced endophthalmitis. This was commonly reported in active young to middle-aged patients. Vitreoretinal surgery and local or systemic administration of sensitive antimicrobial agents seem to be key to successful treatment. Other conditions such as infective endocarditis, meningitis, peritonitis, and pyothorax have also been reported as forms of E. casseliflavus infection. This review clarifies the clinical features of E. casseliflavus infection and provides important insights into its treatment.

Evaluation of an immunological assay for the identification of multiple carbapenemase-producing Gram-negative bacteria.

Carbapenemase-producing Gram-negative organisms (CPOs) frequently gain multidrug-resistant phenotypes and thereby limit the therapeutic options available. Colonisation and infection with CPOs are critical risks for mortality in clinical settings, especially in critical care medicine. Carbapenemase genes on plasmids have transferred to many Gram-negative species, and these species have spread, leading to global concern regarding antimicrobial resistance. A molecular rapid diagnostic test (mRDT) for CPOs is urgently required in critical care medicine. Here, we evaluated a rapid lateral flow immunoassay (LFIA) for CPOs isolated from patients at university hospitals, including intensive care units, and compared the results with those obtained using the multiplex polymerase chain reaction (PCR) method. NG-test CARBA 5 detected multiple carbapenemases, KPC, OXA-48, NDM, VIM, and IMP variants expressed in clinical isolates. Quick Chaser IMP detected IMP variants. The LFIAs exhibited 100% sensitivity and specificity relative to clinical isolates on agar plates. By contrast, the multiplex PCR method exhibited a limited ability to detect IMP-7-producing isolates not belonging to the IMP1 group, which resulted in 97% sensitivity and 100% specificity for IMP-producing isolates. Our results demonstrate that the LFIA is a useful mRDT to identify CPOs and has an advantage over the PCR method for both detection time and sensitivity to the IMP groups. LFIA could complement the nucleic acid amplification test used to identify CPOs. In conclusion, we evaluated sensitive and specific LFIAs capable of detecting carbapenemase production in Gram-negative bacteria. We anticipate that LFIAs will become a point-of-care test enabling rapid detection of carbapenemases in hospital settings, particularly in intensive care units.