Michael A Washington

Effectiveness of a Dental Unit Waterline Treatment Protocol With A-Dec ICX and Citrisil Disinfectants.

This study evaluated the effectiveness of a Dental Unit Waterline disinfection protocol utilizing two waterline disinfectant tablets in a dental treatment clinic. The water effluent from 47 dental treatment units was sampled to determine bacterial load. Four dental treatment units were shocked with the multivalent Sterilex Ultra liquid biocide, followed by a 5-week course of routine disinfection using either the A-dec ICX or Citrisil effervescing tablets. Aseptic samples were taken twice weekly, and bacterial load was determined. No significant difference was found when comparing A-dec ICX with Citrisil, but a significant difference was seen between the use of either tablet and no tablet. In addition, a survey was conducted to evaluate the effect of user compliance on infection control. The results indicate that proper training, coupled with the use of appropriate disinfectants and shock treatment, are important aspects of maintaining low bacterial burden in dental water lines.

Antibiotic resistance, molecular characterizations, and clinical manifestations of Campylobacteriosis at a military medical center in Hawaii from 2012–2016: a retrospective analysis

Hawaii has one of the highest incidences of Campylobacteriosis in the United States, but there remains little published data on circulating strains or antimicrobial resistance. We characterized 110 clinical Campylobacter isolates (106 C. jejuni, 4 C. coli) processed at Tripler Army Medical Center in Honolulu, HI from 2012–2016. Twenty-five percent of C. jejuni isolates exhibited fluoroquinolone (FQ) resistance, compared with 16% for tetracycline (TET), and 0% for macrolides. Two of the four C. coli isolates were resistant to FQ, TET, and macrolides. C. jejuni isolates further underwent multilocus sequence typing, pulsed-field gel electrophoresis, and molecular capsular typing. Nineteen capsule types were observed, with two capsule types (HS2 and HS9) being associated with FQ resistance (p < 0.001 and p = 0.006, respectively). HS2 FQ-resistant isolates associated with clonal complex 21, possibly indicating clonal spread in FQ resistance. Macrolides should be considered for treatment of suspect cases due to lack of observed resistance.

An Analysis of Staphylococcus aureus Infections at a Military Medical Center Using the PLEX-ID Combined Polymerase Chain Reaction-Mass Spectrometry System

Staphylococcus aureus (S. aureus) is a major cause of morbidity in the military health care setting. Culture-based methods are the most common means of identifying infections caused by this agent. However, culture-based methods lack sensitivity and specificity. The Abbott PLEX-ID instrument uses a combination of the polymerase chain reaction and mass spectrometry for the identification of bacterial isolates. We investigated whether the Abbott PLEX-ID system could identify S. aureus in clinical material and facilitate the epidemiological analysis of individual isolates. The PLEX-ID system positively identified 100% of isolates previously found to be methicillin resistant S. aureus by culture. In addition, analysis using the PLEX-ID software revealed that the majority of S. aureus isolates at Tripler Army Medical Center derive from clonal complex 8 and nearly 100% of these strains express the R-variant of the Panton-Valentine leukocidin virulence factor. These results demonstrate the utility of the PLEX-ID system in identifying clinical isolates and reveal an unexpected level of homogeneity among clinical S. aureus isolates recovered at Tripler Army Medical Center. These results also demonstrate the utility of the PLEX-ID system in identifying the resistance patterns, predicting the virulence properties, and tracking the migration of bacterial pathogens in the clinical setting.