Oropharyngeal Bacterial Colonization after Chlorhexidine Mouthwash in Mechanically Ventilated Critically Ill Patients

Contamination of equipment and surfaces in the operating room anesthesia workspace: a cross-sectional study

BACKGROUND

Contamination of the breathing circuit and medication preparation surface of an anesthesia machine can increase the risk of cross-infection.

OBJECTIVE

To evaluate the contamination of the anesthetic medication preparation surface, respiratory circuits, and devices used in general anesthesia with assisted mechanical ventilation.

DESIGN AND SETTING

Cross-sectional, quantitative study conducted at the surgical center of a philanthropic hospital, of medium complexity located in the municipality of Três Lagoas, in the eastern region of the State of Mato Grosso do Sul.

METHODS

Eighty-two microbiological samples were collected from the breathing circuits. After repeating the samples in different culture media, 328 analyses were performed.

RESULTS

A higher occurrence of E. coli, Enterobacter spp., Pseudomonas spp., Staphylococcus aureus, and Streptococcus pneumoniae (P < 0.001) were observed. Variations were observed depending on the culture medium and sample collection site.

CONCLUSION

The study findings underscore the inadequate disinfection of the inspiratory and expiratory branches, highlighting the importance of stringent cleaning and disinfection of high-touch surfaces.

Comparison of global decolonization efficacy with mupirocin nasal drop and chlorhexidine mouthwash in acute leukemia patients: randomized clinical trial

PURPOSE

Neutropenic fever remains a major complication in acute leukemia. Decolonization is assumed as a promising intervention for eradicating causative agents of infection.

METHODS

In this randomized clinical trial, 96 patients with acute leukemia were assigned randomly to mupirocin nasal drop 2% (n = 32), chlorhexidine mouthwash 0.2% (n = 33), and control group (n = 31). In control group, patients did not receive any medication for decolonization. All patients received treatment for 5 days (2 days prior to chemotherapy until 3 days after chemotherapy). Pharynx and nasal swabs were taken prior to the intervention and at the end of decolonization period in all groups. Antibiotic susceptibility testing was performed by the disc diffusion method in order to identify bacterial isolates.

RESULTS

Bacterial recovery of both nasal and pharynx swabs was observed after global decolonization with mupirocin nasal drop. Decolonization with mupirocin significantly eradicated Coagulase-negative staphylococci (CONS) in both nasal and pharynx swabs (p-value = 0.000). Moreover, mupirocin decreased Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) species. Chlorhexidine mouthwash significantly eradicated CONS in pharynx swabs (p-value = 0.000). In addition, both decolonization strategies decreased both antibiotic use and frequency of fever in leukemic patients.

CONCLUSION

Global decolonization with mupirocin nasal drop not only eradicates both nasal and pharynx microorganisms, but also reduces antibiotic requirement and frequency of fever in patients with acute leukemia. The protocol of the present study was approved on December 2016 (registry number: IRCT20160310026998N6).

Reduced chlorhexidine susceptibility is associated with tetracycline resistance tet genes in clinical isolates of Escherichia coli

Chlorhexidine is a widely used antiseptic in hospital and community healthcare. Decreased susceptibility to this compound has been recently described in Klebsiella pneumoniae and Pseudomonas aeruginosa, together with cross-resistance to colistin. Surprisingly, few data are available for Escherichia coli, the main species responsible for community and healthcare-associated infections. In order to decipher chlorhexidine resistance mechanisms in E. coli, we studied both in vitro derived and clinical isolates through whole-genome sequence analysis. Comparison of strains grown in vitro under chlorhexidine pressure identified mutations in the gene mlaA coding for a phospholipid transport system. Phenotypic analyses of single-gene mutant from the Keio collection confirmed the role of this mutation in the decreased susceptibility to chlorhexidine. However, mutations in mlaA were not found in isolates from large clinical collections. In contrast, genome wide association studies (GWAS) showed that, in clinical strains, chlorhexidine reduced susceptibility was associated with the presence of tetA genes of class B coding for efflux pumps and located in a Tn10 transposon. Construction of recombinant strains in E. coli K-12 confirmed the role of tetA determinant in acquired resistance to both chlorhexidine and tetracycline. Our results reveal two different evolutionary paths leading to chlorhexidine decreased susceptibility: one restricted to in vitro evolution conditions and involving a retrograde phospholipid transport system; the other observed in clinical isolates associated with efflux pump TetA. None of these mechanisms provides cross-resistance to colistin. This work demonstrates the GWAS power to identify new resistance mechanisms in bacterial species.

Effect of 0.12% Chlorhexidine Use for Oral Care on Ventilator-Associated Respiratory Infections: A Randomized Controlled Trial

BACKGROUND

Evidence suggests that the effect of 0.12% chlorhexidine (CHX) use for oral care on the development of ventilator-associated pneumonia (VAP) and ventilator-associated tracheobronchitis (VAT) is lacking. Evidence-based approaches to the prevention of VAP and VAT are of paramount importance for improving patients' outcomes.

OBJECTIVES

This study aimed to (1) compare the effect of 0.12% CHX use for oral care on preventing VAP and VAT with the placebo group, as well as (2) compare its effect on oral health and prevention of oral microbial colonization with the placebo group.

METHODS

Prospective, single-blinded, randomized controlled trial performed in 2 intensive care units at a hospital. The sample comprised 57 mechanically ventilated adults randomly allocated to the 0.12% CHX group and the placebo group. Barnason's oral assessment guide was used to evaluate the oral health of both groups before oral care during the first 24 hr of tracheal intubation (Day 0) and at Day 2 and Day 3. Oropharyngeal secretion, endotracheal tube aspirate, and nonbronchoscopic bronchoalveolar lavage samples were collected on Day 0 and Day 3.

RESULTS

The rate of VAT development was not statistically different between the groups (p = .318). However, a significant difference existed in the rate of VAP development (p = .043). The frequency of oropharyngeal colonization significantly decreased in the 0.12% CHX group compared with the placebo group at Day 3 (p = .001).

CONCLUSION

The use of 0.12% CHX for oral care could be effective for VAP prevention and reducing microbial colonization in mechanically ventilated patients.

Antimicrobial Effect of a Peptide Containing Novel Oral Spray on Streptococcus mutans

Objective

To investigate the antibacterial effect of a novel antimicrobial peptide containing oral spray GERM CLEAN on Streptococcus mutans (S. mutans) in vitro and further explore the related mechanisms at phenotypic and transcriptional levels.

Methods

The disk diffusion method was used to preliminarily appraise the antimicrobial effect of GERM CLEAN. The minimal inhibitory concentration (MIC) of GREM CLEAN towards S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method.

Results

The diameter (10.18 ± 1.744 mm) of inhibition zones formed by GERM CLEAN preliminarily indicated its inhibitory effect on the major cariogenic bacteria S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method. S. mutans was determined by the broth dilution method. gtfB, gtfC, gtfD, and ldh were significantly repressed by treating with GERM CLEAN, and this was consistent with our phenotypic results.

Conclusion

The novel antimicrobial peptide containing oral spray GERM CLEAN has an anti-Streptococcus mutans effect and the inhibitory property may be due to suppression of the virulence factors of S. mutans including adhesive, acidogenicity, EPS, and biofilm formation.Streptococcus mutans effect and the inhibitory property may be due to suppression of the virulence factors of S. mutans including adhesive, acidogenicity, EPS, and biofilm formation.S. mutans was determined by the broth dilution method.