Prolonged carriage of ESBL-producing enterobacterales and potential cross-transmission among residents in geriatric long-term care facilities.

Previous studies indicated residents in geriatric long-term care facilities (LTCFs) had much higher prevalence of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) carriage than the general population. Most ESBL-E carriers are asymptomatic. The study tested the hypothesis that residents with ESBL-E carriage may accumulate inside geriatric LTCFs through potential cross-transmission after exposure to residents with prolonged ESBL-E carriage. 260 residents from four Japanese LTCFs underwent ESBL-E testing of fecal specimens and were divided into two cohorts: Cohort 1,75 patients with ≥ 2 months residence at study onset; Cohort 2, 185 patients with < 2 months residence at study onset or new admission during the study period. Three analyses were performed: (1) ESBL-E carriage statuses in Cohort 1 and Cohort 2; (2) changes in ESBL-E carriage statuses 3-12 months after the first testing and ≥ 12 months after the second testing; and (3) lengths of positive ESBL-E carriage statuses. Compared with the residents in Cohort 1, a significantly larger proportion of residents in Cohort 2 were positive for ESBL-E carriage (28.0% in Cohort 1 vs 40.0% in Cohort 2). In the subsequent testing results, 18.3% of residents who were negative in the first testing showed positive conversion to ESBL-E carriage in the second testing, while no patients who were negative in the second testing showed positive conversion in the third testing. The maximum length of ESBL-E carriage was 17 months. The findings indicated that some residents acquired ESBL-E through potential cross-transmission inside the LTCFs after short-term residence. However, no residents showed positive conversion after long-term residence, which indicates that residents with ESBL-E carriage may not accumulate inside LTCFs. Practical infection control and prevention measures could improve the ESBL-E prevalence in geriatric LTCFs.

Improvement of hand hygiene adherence among staff in long-term care facilities for elderly in Japan.

INTRODUCTION: Hand hygiene is crucial for infection control in long-term care facilities for elderly (LTCFEs), because it can be easily implemented in the low-resource settings of LTCFEs. This study investigated the actual status of hand hygiene adherence in LTCFEs, identified the factors inhibiting its appropriate implementation, and evaluated the effectiveness of a hand hygiene promotion program. METHODS: In this before-and-after study, participants were staff members (n = 142) at two LTCFEs in Gunma Prefecture, Japan. We modified the World Health Organization's "five moments for hand hygiene" and assessed participants' hand hygiene adherence rates in four situations: (1) Before touching around a resident's mucous membrane area; (2) Before medical practice or clean/aseptic procedures; (3) After body fluid exposure/risk or after touching around a resident's mucous membrane area; and (4) After touching a resident's contaminated environments. The study was divided into four phases. In Phase 1, participants self-assessed their hand hygiene adherence using a questionnaire. In Phase 2, we objectively assessed participants' pre-intervention adherence rates. In Phase 3, an intervention comprising various hand hygiene promotion measures, such as education and hands-on training on hand hygiene practices and timings, was implemented. In Phase 4, participants' post-intervention adherence rates were objectively measured. RESULTS: Although most participants reported high hand hygiene adherence rate in the self-assessment (93.1%), the pre-intervention evaluation revealed otherwise (16.8%). Participants' post-intervention adherence rates increased for all four situations (77.3%). CONCLUSION: The intervention program helped increase participants' hand hygiene adherence rates, indicating its effectiveness. Similar interventions in other LTCFEs may also improve adherence rates.

Influenza Outbreak and a Group Meal in a Geriatric Long-term Care Facility in Japan.

Influenza outbreaks at geriatric long-term care facilities (g-LTCFs) can be deadly and their prevention is important. However, the factors influencing disease transmission in g-LTCFs remain controversial. In this descriptive study, we tried to identify the potential risk factors influencing influenza outbreaks that occurred in different influenza seasons within a single g-LTCF with 100 residents in Gunma Prefecture. We reviewed the detailed facility records for all influenza cases in both residents and staff between January 2012 and June 2020. Facility preventive measures were also reviewed. We found that community meals may have been a potential source of transmission leading to the outbreaks. When influenza infection is noted, implementation of strict preventive measures and restriction of meal provision to resident rooms may help to prevent disease transmission and the development of an outbreak. Such measures may also be useful to prevent the transmission of other serious droplet-borne diseases within g-LTCFs.

Distribution of Extended-Spectrum ß-Lactamase Genes and Antimicrobial Susceptibility among Residents in Geriatric Long-Term Care Facilities in Japan.

A high prevalence of extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-PE) may call for monitoring in geriatric long-term care facilities (g-LTCFs). We surveyed the distribution of ESBL-causative gene types and antimicrobial susceptibility in ESBL-PE strains from residents in g-LTCFs, and investigated the association between ESBL-causative gene types and antimicrobial susceptibility. First, we analyzed the types of ESBL-causative genes obtained from 141 ESBL-PE strains collected from the feces of residents in four Japanese g-LTCFs. Next, we determined the minimum inhibitory concentration values for alternative antimicrobial agents against ESBL-PE, including ß-lactams and non-ß-lactams. Escherichia coli accounted for 96% of the total ESBL-PE strains. Most strains (94%) contained blaCTX-M group genes. The genes most commonly underlying resistance were of the blaCTX-M-9 and blaCTX-M-1 groups. Little difference was found in the distribution of ESBL-causative genes among the facilities; however, antimicrobial susceptibility differed widely among the facilities. No specific difference was found between antimicrobial susceptibility and the number of ESBL-causative genes. Our data showed that ESBL-PEs were susceptible to some antimicrobial agents, but the susceptibility largely differed among facilities. These findings suggest that each g-LTCF may require specific treatment strategies based on their own antibiogram. Investigations into drug resistance should be performed in g-LTCFs as well as acute medical facilities.

Association between length of residence and prevalence of MRSA colonization among residents in geriatric long-term care facilities.

BACKGROUND: A high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization has been reported among residents in geriatric long-term care facilities (LTCFs). Some studies indicate that MRSA might be imported from hospitals into LTCFs via resident transfer; however, other studies report that high MRSA prevalence might be caused by cross-transmission inside LTCFs. We aimed to assess which factors have a large impact on the high MRSA prevalence among residents of geriatric LTCFs. METHODS: We conducted a cohort study among 260 residents of four geriatric LTCFs in Japan. Dividing participants into two cohorts, we separately analyzed (1) the association between prevalence of MRSA carriage and length of LTCF residence (Cohort 1: n = 204), and (2) proportion of residents identified as MRSA negative who were initially tested at admission but subsequently identified as positive in secondary testing performed at ≥2 months after their initial test (Cohort 2: n = 79). RESULTS: Among 204 residents in Cohort 1, 20 (9.8%) were identified as positive for MRSA. Compared with residents identified as MRSA negative, a larger proportion of MRSA-positive residents had shorter periods of residence from the initial admission (median length of residence: 5.5 vs. 2.8 months), although this difference was not statistically significant (p = 0.084). Among 79 residents in Cohort 2, 60 (75.9%) were identified as MRSA negative at the initial testing. Of these 60 residents, only one (1.7%) had subsequent positive conversion in secondary MRSA testing. In contrast, among 19 residents identified as MRSA positive in the initial testing, 10 (52.6%) were negative in secondary testing. CONCLUSIONS: The prevalence of MRSA was lower among residents with longer periods of LTCF residence than among those with shorter periods. Furthermore, few residents were found to become MRSA carrier after their initial admission. These findings highlight that MRSA in LTCFs might be associated with resident transfer rather than spread via cross-transmission inside LTCFs.

Cholesterol-Induced Formation of Liquid Ordered Phase-Like Structures in Non-Phospholipid Systems.

The formation of liquid ordered (Lo) phase-like structures in stearyltrimethylammonium chloride/cholesterol/1,3-butanediol/water and hepta(oxyethylen) octadecyl ether/cholesterol/1,3-butanediol/water systems was investigated. Differential scanning calorimetry and X-ray scattering measurements confirmed that Lo phase-like structures were formed in both surfactant/cholesterol systems, similar to the lysophospholipid/cholesterol system. It was revealed that the concentration of cholesterol at which only Lo phase-like structures are formed increases in the order stearyltrimethylammonium chloride < lysophospholipid < hepta(oxyethylen) octadecyl ether. In addition, for both surfactants, the interlayer spacing, d, was larger for Lo phase-like structures than for α-gel structures. These results suggest that the ionicity and structure of the hydrophilic group of each surfactant play important roles.

Study on the formation of liquid ordered phase in lysophospholipid/cholesterol/1,3-butanediol/ water and lysophospholipid/ceramide/1,3- butanediol/water systems.

Formation of a liquid ordered phase in lysophospholipid/cholesterol/1,3-butanediol/water and lysophospholipid/ceramide/1,3-butanediol/water systems was investigated. Differential scanning calorimetry confirmed that a liquid ordered phase was formed in the lysophospholipid/cholesterol/1,3-butanediol/water system similar to that in phospholipid systems. The structure of liquid ordered phase was analyzed by using X-ray scattering measurements. It was revealed that the liquid ordered phase has a lamellar structure in which the hydrophobic chains are less ordered than in α-type crystals. On the other hand, in the lysophospholipid/ceramide/1,3-butanediol/water system, a liquid ordered phase was not formed.

Phase behavior and hydrated solid structure in lysophospholipid/long-chain alcohol/water system and effect of cholesterol addition.

Phase behavior in lysophospholipid/long-chain alcohol/water system at 80°C was investigated using hexanol and oleyl alcohol as the long-chain alcohol. Similarly to hydrophilic surfactant, a micellar phase in a lysophospholipid/water system transitioned to a lamellar liquid-crystalline phase by the addition of long-chain alcohol. In the oleyl alcohol system the lamellar liquid-crystalline phase was observed in wider region compared to the hexanol system. The effect of cholesterol addition on the phase behavior was also studied. The region of liquid-crystalline phase and (reverse micellar + liquid-crystalline + water) phase shifted towards higher lysophospholipid concentrations. The structure of hydrated solid as well as the transition between lamellar liquid-crystalline phase and hydrated solid was analyzed by X-ray scattering measurement and differential scanning calorimetry measurement. It was revealed that the hydrated solid was α-type crystals with lamellar structure. The hydrated solid (gel)-liquid crystal transition temperature gradually decreased with increasing oleyl alcohol concentration and the decrement was enhanced by the addition of cholesterol.

Possible vascular role of increased plasma arginine vasopressin in congestive heart failure.

BACKGROUND: The present study was undertaken to determine the relation of cardiac dysfunction with hormonal release in patients with congestive heart failure. METHODS: Seventy-two patients with congestive heart failure were examined, who were divided into four subgroups classified by the criteria of the New York Heart Association (NYHA). Also, 10 age-matched subjects were served as a control. Plasma arginine vasopressin (AVP), norepinephrine, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were determined. Cardiac index and pulmonary capillary wedge pressure (PCWP) were measured in 51 of 72 patients. RESULTS: Plasma AVP levels were significantly increased according to the severity of NYHA classes; control: 1.7 +/- 0.2; NYHA I: 4.9 +/- 0.8, NYHA II: 5.5 +/- 0.9, NYHA III: 13.4 +/- 2.6 (p < 0.05), NYHA IV: 26.9 +/- 5.6 pmol/l (p < 0.001). Similar results were obtained with plasma norepinephrine, ANP and BNP. Plasma AVP levels had negative correlation with cardiac index (r = -0.36, p < 0.01), but did not with PCWP and plasma osmolality. Plasma BNP levels positively correlated with PCWP (r = 0.44, p < 0.001), but did not with cardiac index. There was no correlation between plasma AVP and BNP. Intensive therapy profoundly reduced all the hormones according to the improvement of cardiac index in the patients with NYHA class III and IV. The percent decrease in plasma AVP was 60.0%, a value greater than that in plasma BNP. CONCLUSION: The present study indicates that increased AVP may deteriorate cardiac function through V(1a) as well as V(2) action, and that plasma AVP level is also a proper marker for the presence and severity of congestive heart failure.

Urinary excretion of aquaporin-2 water channel exaggerated dependent upon vasopressin in congestive heart failure.

BACKGROUND: Impaired water excretion occurs in patients with congestive heart failure. The present study was undertaken to determine whether urinary excretion of aquaporin-2 (AQP-2) water channel is exaggerated in patients with congestive heart failure dependent upon arginine vasopressin (AVP). METHODS: Sixty-five patients with congestive heart failure and eight age- and gender-matched control subjects were examined. The patients were divided into four groups according to the criteria of New York Heart Association (NYHA). Plasma AVP levels, urinary excretion of AQP-2, and cardiac index were determined. RESULTS: Plasma AVP levels were progressively increased following the severity of NYHA class in the patients with congestive heart failure. Cardiac index was inversely decreased, and there was a negative correlation between plasma AVP levels and cardiac index (r=-0.430, P < 0.02). Urinary excretion of AQP-2 was 187.3 +/- 50.2 fmol/mg creatinine in the control subjects. It was markedly increased in the patients. Urinary excretion of AQP-2 was elevated to 1144.4 +/- 257.5 and 990.5 +/- 176.0 fmol/mg creatinine in the patients with NYHA class III and class IV, respectively, values significantly greater than the control subjects (P < 0.05). Urinary excretion of AQP-2 had a positive correlation with plasma AVP levels (r= 0.280, P < 0.02). CONCLUSION: The present study indicates that exaggerated urinary excretion of AQP-2 is dependent on baroreceptor-mediated release of AVP in patients with congestive heart failure.

Proton-Induced Tuning of Electrochemical and Photophysical Properties in Mononuclear and Dinuclear Ruthenium Complexes Containing 2,2'-Bis(benzimidazol-2-yl)-4,4'-bipyridine: Synthesis, Molecular Structure, and Mixed-Valence State and Excited-State Properties.

A series of mono- and dinuclear Ru(bpy)(2) complexes (bpy = 2,2'-bipyridine) containing 2,2'-bis(benzimidazol-2-yl)-4,4'-bipyridine (bbbpyH(2)) were prepared. The mononuclear complex [Ru(bpy)(2)(bbbpyH(2))](ClO(4))(2).CH(3)OH.4H(2)O was characterized by an X-ray structure determination. Crystal data are as follows: triclinic, space group P&onemacr;, a = 14.443(4) Å, b = 15.392(4) Å, c = 11.675(2)Å, alpha = 101.44(2) degrees, beta = 107.85(2) degrees, gamma = 96.36(2) degrees, V = 2380(1) Å(3), Z = 2. The coordination geometry of the ruthenium(II) ion is approximately octahedral. The dihedral angle between the two pyridyl rings in bbbpyH(2) is 9.4(3) degrees, which is close to coplanar, in the complex. Mono- and dinuclear complexes exhibit broad charge-transfer absorption bands at 420-520 nm and emission at 660-720 nm in CH(3)CN solution with lifetimes of 200-800 ns at room temperature. Transient difference absorption spectra and resonance Raman (rR) spectra were used to assign the charge-transfer bands in the 420-520 nm region and to identify the lowest excited states. Both absorption and emission spectra are sensitive to solvent and solution pH. Deprotonation of the dinuclear complex raises the energies of the pi orbitals of the bbbpyH(2) ligand, so that they become closer in energy to the pi orbitals of bpy. The intervalence band of [(bpy)(2)Ru(bbbpyH(2))Ru(bpy)(2)](5+)()()is observed at 1200 nm ( epsilon = 170 M(-)(1) cm(-)(1)) in CH(3)CN. The value of the electronic coupling matrix element, H(AB), was determined as 120 cm(-)(1). Upon deprotonation, the IT band was not observed. It is therefore concluded that a superexchange pathway occurs predominantly via the Ru(II) dpi-bbbpyH(2) pi interaction, since deprotonation decreases the interaction. The role of the intervening fragments in the bridging ligand is discussed from the viewpoint of orbital energies and their orbital mixing with Ru dpi orbitals.