Foley catheter with noble metal alloy coating for preventing catheter-associated urinary tract infections: a large, multi-center clinical trial

Background

Catheter-associated urinary tract infections (CAUTI) are among the most frequent healthcare-associated infections in the world. They are associated with increased mortality, prolonged hospital stay and increased healthcare costs. The objective of this study was to evaluate the efficacy of the noble metal alloy (NMA) coated BIP Foley Catheter in preventing the incidence of symptomatic CAUTI in a large cohort of patients in India.

Methods

This multi-center, prospective study included 1000 adult patients admitted to six hospitals across India for urology, surgery and ICU requiring urethral catheterization and admission for ≥ 48 h. Patients were allocated to the NMA-coated BIP Foley Catheter group or a non-coated control catheter group, with a randomization ratio of 3:1. CAUTI surveillance was conducted at study entry, upon catheter removal, and 2 days after catheter removal. For statistical analysis, categorical data (e.g. gender) were compared using the chi-square or Fischer test, and numerical data were compared using the two-sample t-test. Associations were evaluated using logistic regression.

Results and conclusions

The incidence of symptomatic CAUTI was reduced by 69% in the BIP Foley Catheter group compared to the control group (6.5 vs 20.8 CAUTI/1000 catheter days), with an incidence rate ratio of 0.31 (95% confidence interval: 0.21–0.46; p < 0.001). A reduction in the cumulative CAUTI incidence was evident in the BIP Foley Catheter group within 3 days after catheterization; this reduction was maintained up to ~ 30 days, and the largest reductions were seen between 3 and 11 days. There were no serious adverse events related to either catheter, and the percentage of patients with ≥ 1 adverse event was significantly lower in the NMA-coated BIP Foley Catheter group than in the control group (21.6% vs. 48.4%; p = 0.001). In conclusion, the NMA-coated BIP Foley Catheter was effective in reducing CAUTI and was well tolerated, with a lower incidence of adverse events compared to the uncoated catheter.

Trial registration This study was registered prospectively (28 September 2015) in the Clinical Trials Registry of India (trial number CTRI/2015/09/006220; http://ctri.nic.in/Clinicaltrials/showallp.php?mid1=12631&EncHid=&userName=bactiguard).

Long-term use of noble metal alloy coated urinary catheters reduces recurrent CAUTI and decreases proinflammatory markers

Background:

The objective of this study was to investigate a case of a permanently (suprapubic) catheterized woman with neurogenic bladder dysfunction. The patient had suffered from recurrent catheter-associated urinary tract infections (CAUTIs) since 2009, despite several prevention approaches and attempts. In 2013, the patient’s catheter was substituted for the BIP Foley Catheter, coated with a noble metal alloy (NMA) of gold, silver, and palladium.

Method:

This is a retrospective–prospective clinical case study covering 4 years history for the control catheters and up to 2.5 years for the anti-infective BIP Foley Catheter. CAUTI incidences, symptoms, antibiotics, catheter performance, and comfort were evaluated. Levels of proinflammatory cytokines were measured pre- and post-substitution to BIP Foley Catheter in urine of the case and of four other permanently catheterized patients. In addition, the levels of noble metals were assessed in urine of the case subject during use of the BIP Foley Catheter.

Results:

While using control catheters, the patient experienced symptomatic CAUTIs requiring antibiotics almost every month for 4 years. After 1 month with the BIP Foley Catheter, the symptoms disappeared, and the patient remained free of symptomatic CAUTIs and antibiotic treatment for the following 2.5 years, despite bacteriuria. The patient was satisfied with the comfort during insertion, use, and removal of the BIP Foley Catheter. Urinary levels of the proinflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor alpha (TNFα) decreased towards normal levels post catheter type substitution. Traces of noble metals detected in a few urine samples were ⩽4% of the permitted daily exposure. The levels of the noble metals gold, silver, and palladium remaining on the BIP Foley Catheter after use were the same as for unused catheters.

Conclusion:

Long-term use of a NMA-coated catheter was associated with cessation of frequent CAUTIs. The catheter was experienced as comfortable and inflammatory markers were reduced with time. The coating was stable, with no significant metal release into urine and is therefore safe for patient use.

A review of the innate immune defence of the human foetus and newborn, with the emphasis on antimicrobial peptides

At birth, the foetus makes the transition from the uterus to a world full of microbes. The newborn baby needs protection against potential invading pathogens and needs to establish a normal microbiota.

CONCLUSION

Antimicrobial peptides and proteins are key effector molecules of innate immunity and are also important immunomodulators. Their presence in the cells and tissues of the uterus, foetus and the neonate indicates an important role in immunity during pregnancy and in early life.

Somatostatin and its 2A receptor in dorsal root ganglia and dorsal horn of mouse and human: expression, trafficking and possible role in pain

Background

Somatostatin (SST) and some of its receptor subtypes have been implicated in pain signaling at the spinal level. In this study we have investigated the role of SST and its sst2A receptor (sst2A) in dorsal root ganglia (DRGs) and spinal cord.

Results

SST and sst2A protein and sst2 transcript were found in both mouse and human DRGs, sst2A-immunoreactive (IR) cell bodies and processes in lamina II in mouse and human spinal dorsal horn, and sst2A-IR nerve terminals in mouse skin. The receptor protein was associated with the cell membrane. Following peripheral nerve injury sst2A-like immunoreactivity (LI) was decreased, and SST-LI increased in DRGs. sst2A-LI accumulated on the proximal and, more strongly, on the distal side of a sciatic nerve ligation. Fluorescence-labeled SST administered to a hind paw was internalized and retrogradely transported, indicating that a SST-sst2A complex may represent a retrograde signal. Internalization of sst2A was seen in DRG neurons after systemic treatment with the sst2 agonist octreotide (Oct), and in dorsal horn and DRG neurons after intrathecal administration. Some DRG neurons co-expressed sst2A and the neuropeptide Y Y1 receptor on the cell membrane, and systemic Oct caused co-internalization, hypothetically a sign of receptor heterodimerization. Oct treatment attenuated the reduction of pain threshold in a neuropathic pain model, in parallel suppressing the activation of p38 MAPK in the DRGs

Conclusions

The findings highlight a significant and complex role of the SST system in pain signaling. The fact that the sst2A system is found also in human DRGs and spinal cord, suggests that sst2A may represent a potential pharmacologic target for treatment of neuropathic pain.

Lactose in human breast milk an inducer of innate immunity with implications for a role in intestinal homeostasis

Postpartum, infants have not yet established a fully functional adaptive immune system and are at risk of acquiring infections. Hence, newborns are dependent on the innate immune system with its antimicrobial peptides (AMPs) and proteins expressed at epithelial surfaces. Several factors in breast milk are known to confer immune protection, but which the decisive factors are and through which manner they work is unknown. Here, we isolated an AMP-inducing factor from human milk and identified it by electrospray mass spectrometry and NMR to be lactose. It induces the gene (CAMP) that encodes the only human cathelicidin LL-37 in colonic epithelial cells in a dose- and time-dependent manner. The induction was suppressed by two different p38 antagonists, indicating an effect via the p38-dependent pathway. Lactose also induced CAMP in the colonic epithelial cell line T84 and in THP-1 monocytes and macrophages. It further exhibited a synergistic effect with butyrate and phenylbutyrate on CAMP induction. Together, these results suggest an additional function of lactose in innate immunity by upregulating gastrointestinal AMPs that may lead to protection of the neonatal gut against pathogens and regulation of the microbiota of the infant.

Neutrophil primary granule proteins HBP and HNP1-3 boost bacterial phagocytosis by human and murine macrophages

In acute inflammation, infiltrating polymorphonuclear leukocytes (also known as PMNs) release preformed granule proteins having multitudinous effects on the surrounding environment. Here we present what we believe to be a novel role for PMN-derived proteins in bacterial phagocytosis by both human and murine macrophages. Exposure of macrophages to PMN secretion markedly enhanced phagocytosis of IgG-opsonized Staphylococcus aureus both in vitro and in murine models in vivo. PMN secretion activated macrophages, resulting in upregulation of the Fcgamma receptors CD32 and CD64, which then mediated the enhanced phagocytosis of IgG-opsonized bacteria. The phagocytosis-stimulating activity within the PMN secretion was found to be due to proteins released from PMN primary granules; thorough investigation revealed heparin-binding protein (HBP) and human neutrophil peptides 1-3 (HNP1-3) as the mediators of the macrophage response to PMN secretion. The use of blocking antibodies and knockout mice revealed that HBP acts via beta2 integrins, but the receptor for HNP1-3 remained unclear. Mechanistically, HBP and HNP1-3 triggered macrophage release of TNF-alpha and IFN-gamma, which acted in an autocrine loop to enhance expression of CD32 and CD64 and thereby enhance phagocytosis. Thus, we attribute what may be a novel role for PMN granule proteins in regulating the immune response to bacterial infections.

The role of the multifunctional peptide LL-37 in host defense

Neutrophil granules contain several antimicrobial peptides (AMPs) that are important effector molecules of innate immunity. In mammals, the main families of these peptides are the cathelicidins and defensins. Several defensins have been characterized in humans, while there is only one human cathelicidin, designated LL-37. This peptide is stored in specific granules of neutrophils in an inactive proform, which is processed extracellularly to the mature active peptide LL-37 and the propart cathelin after neutrophil degranulation. Apart from exhibiting a broad antimicrobial spectra, it is now evident that LL-37 possesses several additional functions that are related to host defense. Examples of such functions are chemotactic, endotoxin neutralizing, angiogenic and wound healing activities. These effects of LL-37 reveal a role as a mediator between innate and adaptive immunity. This review is giving an overview of the different immunological effects exerted by LL-37 and the physiological significance of these functions in immunity.

Antimicrobial components of the neonatal gut affected upon colonization

Antimicrobial peptides (AMP) produced throughout our body are important effectors in the defense barrier of innate immunity. Here, we have analyzed antimicrobial activity and polypeptide composition of meconium versus neonatal feces to address the development of antimicrobial defense of the neonatal gut. Extracts of meconium exhibited antimicrobial activity against Bacillus megaterium, Escherichia coli, and group B streptococci (GBS) but not against the yeast Candida albicans. Extracts of neonatal feces were found to possess low activity against E. coli, GBS, and C. albicans. However, the anti-B. megaterium activity was higher in the fecal extracts than in meconium. All activities were reduced or abolished when salt was added to the antimicrobial assay. The AMP cathelicidin LL-37, alpha-defensin HNP-1-2, alpha-defensin HD 5, and lysozyme were identified in both meconium and fecal extracts. In addition, HNP-3 and a fragment of azurocidin were found in meconium, whereas the holoprotein azurocidin was detected in feces. In meconium, histones H2A and H4 were isolated and identified by their antimicrobial activity. Notably, LL-37 and lysozyme were found at significantly higher levels in feces than in meconium. Our findings reveal that meconium and feces contain AMP, acting in the defense of the neonatal gut, and may be implicated in the control of the initial colonization.

Vernix caseosa as a multi-component defence system based on polypeptides, lipids and their interactions

Vernix caseosa is a white cream-like substance that covers the skin of the foetus and the newborn baby. Recently, we discovered antimicrobial peptides/proteins such as LL-37 in vernix, suggesting host defence functions of vernix. In a proteomic approach, we have continued to characterize proteins in vernix and have identified 20 proteins, plus additional variant forms. The novel proteins identified, considered to be involved in host defence, are cystatin A, UGRP-1, and calgranulin A, B and C. These proteins add protective functions to vernix such as antifungal activity, opsonizing capacity, protease inhibition and parasite inactivation. The composition of the lipids in vernix has also been characterized and among these compounds the free fatty acids were found to exhibit antimicrobial activity. Interestingly, the vernix lipids enhance the antimicrobial activity of LL-37 in vitro, indicating interactions between lipids and antimicrobial peptides in vernix. In conclusion, vernix is a balanced cream of compounds involved in host defence, protecting the foetus and newborn against infection.