The role of water distribution system in HCAIs

Introduction

The water distribution system in hospitals may constitute a source of healthcare-associated infections. Understanding the means of acquisition, sources and reservoirs of nosocomial pathogens is crucial for developing methods to reduce the incidence of nosocomial infections. The aim of our study was to evaluate the microbiological contamination by Pseudomonas aeruginosa in the water system of the University Hospital “G. Martino” in Messina over a period of nine years, in order to a) clarify possible relationship between the presence of aerators and contamination, b) to highlight the presence of a yearly variation and c) to verify the statistical difference between microbiological contamination of taps with and without filters.

Materials and

Methods

We carried out a retrospective study for nine year through the collection of water samples that were analysed for total bacteria count and Pseudomonas aeruginosa. The differences between the results recorded over the nine-year study period were evaluated using variance analysis. P values of < 0.05 were considered statistically significant. Software R was used for statistical assessment.

Results

We analysed a total of 6168 samples with a positive rate of 9.31% and a decreasing trend over the nine years to a value of 2.44% (p < 0.001), due to the elimination of the aerators of taps without filters and also to the introduction of filters in taps of high-risk wards and surgical rooms. We found statistical difference between taps with or without filter (p < 0.001) and a higher positive rate during the summer season compared to the other months. Also, an increase of the positivity rate was detected in some year due to the lack of monthly replacement of the filter.

Conclusions

These results reveal a high level of contamination of taps by opportunistic bacteria with severe implications especially for high-risk settings and therefore, the need to improve the management of these devices.

Key messages

Particular attention must be reserved to the water distribution systems in hospitals in order to prevent the spread of healthcare associated infections. The continued application and strengthening of guidelines and procedures is essential to limit the spread of multidrug resistant pathogens.

Effects of aerators, filters and chlorination on contamination of water samples: a nine years study in a Southern University Hospital

OBJECTIVES

The aim of our study was to evaluate the microbiological contamination by Pseudomonas aeruginosa in the water system of the University Hospital "G. Martino" in Messina over a period of nine years, in order to a) clarify possible relationship between the presence of aerators and contamination, b) to highlight the presence of a yearly variation and c) to verify the statistical difference between microbiological contamination of taps with and without filters.

MATERIAL AND METHODS

We carried out our study between January 2010 and December 2018 through the collection of water samples that were analysed for total bacteria count and Pseudomonas aeruginosa. The differences between the results recorded over the nine-year study period were evaluated using variance analysis. P values of <0.05 were considered statistically significant. Software R was used for statistical assessment.

RESULTS

We analysed a total of 6168 samples with a positive rate of 9.31% and a decreasing trend over the years to a value of 2.44% (p<0.001), due to the elimination of the aerators of taps without filters and also to the introduction of filters in taps of high-risk wards and surgical rooms. We found statistical difference between taps with or without filter (p<0.001) and a higher positive rate during the summer season compared to the other months.

CONCLUSIONS

These results reveal a high level of contamination of taps by opportunistic bacteria with severe implications especially for high-risk settings and therefore, the need to improve the management of these devices.

Immunoexpression of aquaporin-1 in adolescent varicocele testes: Possible significance for fluid reabsorption

OBJECTIVES

To investigate the immunoexpression of aquaporin-1 (AQP-1), a major transmembrane water channel, in high-grade varicocele testes, which are known to imply an unbalanced transmembrane water flow, in both tubular and extratubular compartments.

METHODS

Light microscopy and AQP-1 immunohistologic examination were carried out on incisional testicular biopsies from 20 adolescent boys, aged 13 to 18 years, with grade 2 or 3 idiopathic varicocele. Testicular tissue from 4 autopsied subjects of matched age were also investigated as parallel controls.

RESULTS

At microscopic examination, the tubular lumina and extracellular matrix were expanded and venular profiles dilated. Cytoplasmic vacuoles were frequent in the Sertoli cells, spermatogonia, and spermatocytes, together with premature sloughing of germ cells and residual cytoplasmic droplets inside the spermatozoa, if present. Diffuse AQP-1 positivity occurred at venular endothelial cell membranes and, unexpectedly, at the cell membranes of the Sertoli cells, diploid germ cells, and haploid cells. In the control testes, focal AQP-1 immunolabeling was confined to the microvessel endothelial cells, without any positive reaction in the tubular or extratubular compartments.

CONCLUSIONS

This is the first report showing AQP-1 cell expression in adolescent varicocele testes in both tubular and extratubular compartments. It was associated with the main histologic features of unbalanced water flow in the tubular and interstitial compartments of the testis. Immunocytochemical patterns revealed AQP-1 as a possible critical reabsorption factor, acting to reduce abnormal fluid retention in endotubular cells and the extracellular matrix and, to a lesser extent, in Leydig cells.