Contamination of blood pressure cuffs by methicillin-resistant Staphylococcus aureus and preventive measures.

BACKGROUND: Although blood pressure cuffs are commonly used and shared in medical facilities, their routine disinfection is performed infrequently. AIMS: We investigated the contamination of blood pressure cuffs by methicillin-resistant Staphylococcus aureus (MRSA). METHODS: The MRSA level on the inner side (the surface in contact with patients' skin) of blood pressure cuffs used in the wards and outpatient clinics of a university hospital (733 beds) was determined using the gauze and swab wiping methods. RESULTS: Using the gauze wiping method (n = 35), the MRSA contamination rate was 31.4 %, and the MRSA contamination level was 1,702.6 ± 9,996.1 (0-58, 320) colony-forming units (cfu)/cuff. No MRSA was detected on blood pressure cuffs after washing (n = 30) or wiping with 80 vol% ethanol (n = 18). CONCLUSIONS: Blood pressure cuffs are frequently contaminated by MRSA.

Microbial contamination of a disinfectant-soaked unwoven cleaning cloth.

In December 2009, a 76-year-old male patient developed pneumonia due to Burkholderia cepacia whilst in an intensive care unit at a Japanese university hospital. During the subsequent environmental investigation to find the source, B. cepacia with an identical DNA type was found in his denture storage solution. Open packets of unwoven rayon cloths soaked in 0.2% alkyldiaminoethylglycine hydrochloride, used for environmental cleaning, were shown to be contaminated with B. cepacia, Alcaligenes xylosoxidans, Pseudomonas fluorescens and Pseudomonas aeruginosa. B. cepacia of a different DNA type was found in five of 42 samples from sealed packets of cloths.

KLF4 suppresses estrogen-dependent breast cancer growth by inhibiting the transcriptional activity of ERalpha.

Kruppel-like factor 4 (KLF4) is a transcription factor that participates in both tumor suppression and oncogenesis. To determine the association of KLF4 with tumorigenesis, we integrated data assembled in the Oncomine database and discovered a decrease in KLF4 gene transcripts in breast cancers. Further analysis of the database also showed a correlation between KLF4 expression and estrogen receptor-alpha (ERalpha) positivity. Knockdown of KLF4 in MCF-7 cells elevated the growth rate of these cells in the presence of estrogen. Therefore, we examined the interaction between KLF4 and ERalpha, and found that KLF4 bound to the DNA-binding region of ERalpha. KLF4 thus inhibits the binding of ERalpha to estrogen response elements in promoter regions, resulting in a reduction in ERalpha target gene transcription. Earlier studies have reported that KLF4 is transcriptionally activated by p53 following DNA damage. We also showed that activation of p53 decreased the transcriptional activity of ERalpha by elevating KLF4 expression. Our studies discovered a novel molecular network between p53, KLF4 and ERalpha. As both p53 and ERalpha are involved in cell growth and apoptosis, these results may explain why KLF4 possesses both tumor suppressive and oncogenic functions in breast cancers.

Akt-dependent nuclear localization of Y-box-binding protein 1 in acquisition of malignant characteristics by human ovarian cancer cells.

Y-box-binding protein 1 (YB-1), which is a member of the DNA-binding protein family containing a cold-shock domain, has pleiotropic functions in response to various environmental stimuli. As we previously showed that YB-1 is a global marker of multidrug resistance in ovarian cancer and other tumor types. To identify YB-1-regulated genes in ovarian cancers, we investigated the expression profile of YB-1 small-interfering RNA (siRNA)-transfected ovarian cancer cells using a high-density oligonucleotide array. YB-1 knockdown by siRNA upregulated 344 genes, including MDR1, thymidylate synthetase, S100 calcium binding protein and cyclin B, and downregulated 534 genes, including CXCR4, N-myc downstream regulated gene 1, E-cadherin and phospholipase C. Exogenous serum addition stimulated YB-1 translocation from the cytoplasm to the nucleus, and treatment with Akt inhibitors as well as Akt siRNA and integrin-linked kinase (ILK) siRNA specifically blocked YB-1 nuclear localization. Inhibition of Akt activation downregulated CXCR4 and upregulated MDR1 (ABCB1) gene expression. Administration of Akt inhibitor resulted in decrease in nuclear YB-1-positive cancer cells in a xenograft animal model. Akt activation thus regulates the nuclear translocation of YB-1, affecting the expression of drug-resistance genes and other genes associated with the malignant characteristics in ovarian cancer cells. Therefore, the Akt pathway could be a novel target of disrupting the nuclear translocation of YB-1 that has important implications for further development of therapeutic strategy against ovarian cancers.

Microbial contamination of dialysate and its prevention in haemodialysis units.

At the haemodialysis centres of nine hospitals in Japan, microbial contamination of treated water (reverse osmosis method), acid and bicarbonate concentrates, and dialysate was investigated. Among these fluids used in haemodialysis, the dialysate was most frequently contaminated and had the highest concentration of bacteria. Of 40 dialysate samples analysed, 42.5% showed a bacterial count of more than 2000cfu/mL, which was above the Association for the Advancement of Medical Instrumentation (AAMI) standard. However, among the 40 samples from 20 dialysis machines, all six dialysate samples from three dialysis machines that used an ultrafiltration membrane in the circuit before the entrance of the dialysate into the dialyser, showed a bacterial count of < or =10 cfu/mL. In addition, when an ultrafiltration membrane was used in the circuit before the entrance of the dialysate into the dialyser for four dialysis machines showing dialysate samples contaminated with 10(4)-10(5)cfu/mL the bacterial count in dialysate samples from these machines became zero. Because dialysis machines are susceptible to microbial contamination, it is necessary to take measures such as placing an ultrafiltration membrane into the circuit before the entrance of dialysate into the dialyser.

Contamination of room door handles by methicillin-sensitive/methicillin-resistant Staphylococcus aureus.

We investigated the contamination of room door handles by Staphylococcus aureus in wards of a university hospital. Door handles in 53 (27.0%) of 196 rooms were contaminated by methicillin-sensitive Staphylococcus aureus (MSSA) and/or methicillin-resistant Staphylococcus aureus (MRSA); MSSA was detected on door handles of 41 rooms (20.9%), MRSA on door handles of 17 rooms (8.7%), and MSSA and MRSA on the same door handles of five rooms (2.6%). The density of MSSA contamination was 1-2.6x10(4) colony forming units (cfu)/door handle, and that of MRSA was 1-6.0x10(3) cfu/door handle. The MRSA contamination rate on door handles of rooms with patients with MRSA was 19.0% (4/21 rooms) while that on door handles of rooms with patients without MRSA was 7.4% (13/175); the difference was not significant. These results suggest extensive contamination of MSSA and MRSA in the hospital environment.

Comparison of microbial contamination of enteral feeding solution between repeated use of administration sets after washing with water and after washing followed by disinfection.

We compared microbial contamination of in-use enteral feeding solution from repeatedly used administration sets (a delivery bag and an infusion tube) after washing with water or washing followed by disinfection. In eight hospitals where administration sets were re-used after washing with water, residual solution was collected from both the delivery bag and the distal end of the infusion tube immediately after use and the microbial contamination level and microbial species found examined. The residual enteral feeding solution (28 samples) in the delivery bag grew 10(2)-10(8) colony forming units (cfu)/mL and 36 samples from the distal end of the infusion tube grew 10(2)-10(9) cfu/mL. Re-processing was changed to washing with water followed by disinfection with 0.1% (100 ppm) sodium hypochlorite, and similar examinations were performed. The residual solutions in the bag (22 samples) and in the distal end of the infusion tube (24 samples) were contaminated with < 10(1)-10(4) cfu/mL each, a significant decrease (P < 0.01, Wilcoxon U-test) compared with washing with water alone.

Contamination and survival of Pseudomonas aeruginosa in hospital used sponges.

The microbial contamination of in-use sponges was investigated. Of the sixty sponges examined, 51 (85%) were contaminated with 10(3)-10(9) colony forming units (CFU) per sponge. Pseudomonas aeruginosa was isolated from sixteen (26.7%) of the sixty sponges. P. aeruginosa survived for 2 months in contaminated sponges which were left at room temperature and became dry to the touch. The susceptibility of sponges to P. aeruginosa contamination should be recognized. Once sponges are contaminated with P. aeruginosa, eradication of this organism is difficult even if the sponges are dried.

Microbial contamination of water-soaked cotton gauze and its cause.

Seven in-use cotton gauze samples and three cotton balls soaked in sterile distilled water in canisters were investigated 7 days after they were prepared in hospital. All samples were contaminated with bacteria including 10(6) to 10(7) colony forming units/ml of Pseudomonas aeruginosa. In vitro viability tests using cotton gauze and cotton balls soaked in sterile distilled water revealed rapid proliferation of P. aeruginosa, Serratia marcescens and Candida albicans. Since the cotton gauze and the cotton balls were soaked in water containing nutrients, such as protein and glucose, these materials may be readily contaminated with bacteria including P. aeruginosa. Thus, when using cotton gauze and cotton balls containing water, microbial contamination should be expected.

The induction of apoptosis and inhibition of AP-1 activity by TAC-101 (4-[3,5-bis(trimethylsilyl) benzamido] benzoic acid) may result in life prolonging effect in animals bearing metastasizing cancer.

BACKGROUND: The incidence of cancers of the digestive tract has been high among all of the cancers in Japan and the western hemisphere. The poor prognosis of patients, especially those with liver metastases, has become a great challenge for the development of a new drug to cope with this problem. MATERIALS AND METHODS: Mice implanted by intrasplenic injection of TMK-1, human gastric carcinoma cells, were used to examine the life-prolonging effect of TAC-101. To elucidate a mechanism of action of TAC-101, the drug-induced apoptosis was assessed by DNA ladder formation whilst the prevention of transcription factor AP-1 binding to its DNA recognition sequence was assessed by gel shift assay. RESULTS: TAC-101 showed the life prolonging effect in a model of experimental liver metastasis of TMK-1. The antitumor effect, expressed as T/C (%), was 201, 141 and 112%, for TAC-101 (2 mg/kg), ATRA (8 mg/kg) and 5-FU (19 mg/kg), respectively. The in vitro experiments revealed that the anticancer activity of TAC-101 is related to its ability to induce apoptosis within a short period of time in TMK-1 cells and human leukemic cells, HL-60. TAC-101-induced apoptosis was suppressed by the inhibitors of proteases, specifically by Z-Val-Ala-DL-Asp-fluoromethylketone, indicating the involvement of caspase activation. TAC-101 also inhibited, in a concentration-dependent manner, the binding of AP-1 to its DNA binding sites present in the promoter region of the genes involved in the control of cell migration, invasion, and angiogenesis. CONCLUSION: TAC-101 may suppress liver metastasis by the induction of an apoptotic mechanism(s) in cancer cells and possibly by controlling transcriptional activity of AP-1.

Microbial contamination of in-use lubricants for non-touch urethral catheters in intermittent self-catheterization.

There are no reports on microbial contamination of repeatedly used lubricant (84-87% glycerin containing 0.02% benzalkonium chloride) for non-touch urethral catheters in intermittent self-catheterization. In this work, we evaluated microbial contamination of in-use lubricant and its prevention. Between September and December, 1996, microbial contamination and water activity of in-use lubricants in sheathed and lubricated non-touch catheters connected to a tube used by 46 outpatients at our hospital was examined. Microbial contamination was detected at 5 to 2.6 x 10(8) colony-forming units (CFU)/ml in 14 (30.4%) of 46 samples. With higher water activity of the lubricant (a higher dilution rate of the lubricant with water), a higher concentration of microbial contamination was observed. In 3 (21.4%) of the 14 patients using contaminated lubricant, urine samples showed the same microbial species as those detected in the lubricant. To prevent microbial contamination of the lubricant, dilution of the lubricant with water, as a result of repeated use, should be avoided.

In-vitro effects of a combination of antipseudomonal antibiotics against multi-drug resistant Pseudomonas aeruginosa.

We evaluated the in-vitro effects of various combinations of five types of widely used antipseudomonal antibiotics (piperacillin, meropenem, ceftazidime, aztreonam and amikacin) against six Pseudomonas aeruginosa strains that were resistant to each of these antibiotics. Among two-drug combinations, the combinations of two beta-lactam antibiotics inhibited growth of one to three P. aeruginosa strains, while those of one beta-lactam antibiotic and amikacin inhibited growth of two to four strains. Among three-drug combinations, the combinations of three beta-lactam antibiotics inhibited growth of four to five strains, and those of two beta-lactam antibiotics and amikacin inhibited growth of five strains. These results suggest the potential usefulness of a combination of two beta-lactam antibiotics and amikacin or that of three beta-lactam antibiotics in treating multi-drug resistant P. aeruginosa infections.

Differences in apoptosis induced by anticancer drugs in sublines (SKG-3a, SKG-3b) from a human uterine cervical epidermoid carcinoma.

SKG-3a and SKG-3b are two distinct human uterine cervical epidermoid carcinoma cell lines derived from a single donor. We studied these two closely related cell lines from the standpoint of drug susceptibility. The growth inhibitory effects of cisplatin (CDDP), doxorubicin (ADM), etoposide (VP-16), and paclitaxel (taxol) on SKG-3a and SKG-3b cells assessed by crystalviolet dye uptake assay were almost the same. SKG-3b cells treated with CDDP, ADM, VP-16, and taxol showed the apoptotic cell death, whereas apoptosis in SKG-3a cells was not induced by these anticancer drugs. Caspase-3 activity was increased only in the SKG-3b cell lysate after treatment with CDDP, ADM, and VP-16 but was not found in the SKG-3a cell lysate. These results indicate that despite growth inhibitory effects of anticancer drugs being almost the same, there may be differences in the common signaling pathways involved in the apoptotic process between SKG-3a and SKG-3b obtained from the same tumor.

Efficacy of disinfectants and heat against Escherichia coli O157:H7.

The bactericidal activity of disinfectants and hot water against ten Escherichia coli O157:H7 strains, which were isolated from faeces of patients with enterohaemorrhagic E. coli infection, were evaluated and showed different DNA patterns. After exposure to 0.1% benzalkonium chloride, 0.1% chlorhexidine gluconate containing a nonionic surfactant, and 80% (v/v) ethanol, 99.99% of viable bacterial cells were killed at 20 degrees C within 15 s irrespective of the presence or absence of 0.1% albumin. On the other hand, after exposure to hot water, 99.99% of the bacterial cells were killed within 15 s at 70 degrees C. These results suggest that benzalkonium chloride, chlorhexidine gluconate containing a nonionic surfactant, ethanol, and hot water at 70 degrees C or more are effective for disinfection of E. coli O157:H7 in hospitals.

Clinical pharmacology of moclobemide during chronic administration of high doses to healthy subjects.

The objectives of this study were to assess the tolerability, safety, pharmacodynamics and pharmacokinetics of high-dose moclobemide in healthy subjects. Two sequential groups of six male and six female subjects (eight on active treatment, four on placebo) received for 8 days moclobemide 450 mg b.i.d. and 600 mg b.i.d., respectively. Intravenous tyramine pressor tests were conducted at baseline, at the beginning of treatment and at steady state. Oral tyramine pressor tests with 50, 100 and 150 mg tyramine were conducted under steady-state conditions. Pharmacokinetic parameters of moclobemide and two of its metabolites in plasma and urine were determined after the first and last dose of moclobemide. The incidence and intensity of adverse events was dose-dependent. The most frequently reported adverse events were insomnia, headache, dizziness and dry mouth. The i.v. tyramine pressor sensitivity during both moclobemide dosing regimens was enhanced 3 to 4-fold. Intake of tyramine 50 mg did not result in systolic blood pressure increases greater than 30 mmHg. With regard to blood pressure increases, tyramine 100 mg is still compatible with moclobemide 450 mg b.i.d. but not with 600 mg b.i.d. The clearance of moclobemide decreased by about 60% on multiple dosing, but no differences were found between both dosing regimens. The urinary excretion of the N-oxide metabolite doubled during multiple dosing. In conclusion, the maximum tolerated dose of moclobemide in healthy subjects is 600 mg b.i.d. provided the tyramine content in a meal is not higher than 50 mg.

Microbial contamination of 'sterile water' used in Japanese hospitals.

We examined the following samples of water from 10 hospitals for microbial contamination: water obtained using an ultra filtration system (UF water), a reverse osmosis system (RO water), a water distillation system (distilled water) and tap water. UF water and RO water are used for handwashing before surgery, and distilled water for the preparation of drugs. All 10 samples of tap water examined were contaminated with < 10 colony forming units (cfu)/mL. Thirteen (68%) of 19 samples of UF water, nine (53%) of 17 samples of RO water and 15 (79%) of 19 samples of distilled water were contaminated with 10(1)-10(4) cfu/mL. The majority of micro-organisms were non-fermentative bacteria such as Sphingomonas paucimobilis and CDC gr. IV C-2. Japanese hospitals commonly use UF water and RO water for preoperative handwashing under the assumption that it is sterile. Our results suggest, however, that these types of water are inferior microbiologically to tap water. Distilled water from the dispensary was also contaminated with micro-organisms. The available chlorine content of tap water was 0.17-0.42 ppm and that of UF water (from tap water) 0-0.06 ppm. There was no available chlorine in RO water or distilled water (each from tap water). The reduction or disappearance of available chlorine appears to be associated with microbial contamination of UF water, RO water and distilled water.

Enhanced transepithelial transport of peptides by conjugation to cholic acid.

The potential of the intestinal bile acid transporter to serve as a shuttle for small peptide molecules was investigated. Eleven peptides with a 2-6 amino acid backbone were conjugated to the 24-position of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholan-24-oic acid (cholic acid) via an amide bond using an automated peptide synthesizer. In a human intestinal cell line (CaCo-2), cholic acid-peptide conjugates were able to inhibit the transepithelial transport of [3H]taurocholic acid, a natural substrate for the bile acid carrier, at a 100:1 conjugate/substrate ratio. Affinity for the carrier decreased significantly when the conjugate in the 24-position increased from 1 to 2 amino acids. Further increase in the amino acid chain length caused only minor decrease in affinity. A tetrapeptide-bile acid conjugate, [3H]-ChEAAA (Ch = cholic acid), was transported by the bile acid transporter, showing markedly higher apical (AP)-to-basolateral (BL) compared to BL-to-AP transport and inhibition by a 100-fold excess taurocholic acid. Another conjugate with 6 amino acids (ChEASASA) was transported by a passive diffusion pathway but still showed higher transport rates than the passive permeability marker mannitol, suggesting the possibility that the cholic acid moiety aids the passive membrane transfer of peptide molecules by increasing its lipophilicity. Metabolism of bile acid-peptide conjugates in CaCo-2 cells was 3% over 3 h. In conclusion, these studies show that the coupling of peptides to the 24-position of the sterol nucleus in cholic acid results in a combination of decreased metabolism and increased intestinal absorption, either by a carrier-mediated pathway or by accelerated passive diffusion.

Microbial contamination of antiseptic-soaked cotton balls.

We investigated microbial contamination of in-use antiseptics at a hospital. No microbial contamination was observed in 70 samples of 0.02% benzalkonium chloride solution (500-ml volume), 70 samples of 1% titratable I2 povidone-iodine solution (250-ml volume), or 15 samples of 0.1% ethacridine lactate solution (500-ml volume) during use in reduced amounts. Nor was any microbial contamination observed in 70 samples of cotton balls soaked in 1% titratable I2 povidone-iodine solution in canisters or cotton gauze soaked in 70% (w/v) ethanol solution in canisters. However, among 70 samples of cotton balls soaked in 0.02% benzalkonium chloride solution in canisters, 6 (8.6%) were contaminated with 10(4) to 10(6) viable cells/ml. The microbial species detected were glucose non-fermentative bacilli such as Alcaligenes xylosoxidans and Pseudomonas putida. The contaminants obtained from cotton balls soaked in 0.02% benzalkonium chloride solution did not proliferate in that solution or in distilled water but showed rapid growth in the cotton balls soaked in either of these liquids. These findings suggested that benzalkonium chloride solution tends to become contaminated when cotton balls are immersed. Therefore, cotton balls soaked in benzalkonium chloride solution are not recommended as an antiseptic. When no other choice is available, the cotton balls should be soaked in benzalkonium chloride solution at the time of usage.

In vitro susceptibility of Escherichia coli O157 to several antimicrobial agents.

We evaluated the antimicrobial susceptibility of six strains of Escherichia coli O157 (E. coli O157) isolated from patients in Yamaguchi Prefecture between June and July, 1996. Seven antimicrobial agents that were expected to retain a high concentration in the intestine were selected. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of ciprofloxacin, polymyxin B, cefoperazone, and kanamycin for each strain were < or = 6.25 microg/ml. However, the MIC of fosfomycin was 3.13-100 microg/ml, and its MBC was > or = 100 microg/ml. The MIC of ampicillin and tetracycline was > 100 mcirog/ml in some strains. In a time-kill study of E. coli O157 at a drug concentration of 12.5 microg/ml, about 10(4) colony forming units/ml of E. coli O157 were eradicated within 10 min by ciprofloxacin, within 30 min by polymyxin B, within 4 h by cefoperazone, and within 16 h by kanamycin. These results suggest that the new quinolones with a poor absorption rate in the intestine (such as ciprofloxacin and norfloxacin) are effective against E. coli O157. When oral administration is impossible, bile excreting cephem antibiotics (such as cefoperazone, ceftriaxone, and cefotetan) may be useful.