000			04660nam a22003257a 4500
999			_c111068 _d111068
003			IE-CoIT
005			20220928062641.0
007			ta
008			180314s2016 xxu||||| |||| 00| 0|eng||
040			_aIE-CoIT
082	0	4	_aTHESES PRESS
100	1		_9123914 _aGabriel, Emma _eauthor
245	1		_aClinical coagulase-negative staphylococci : _bidentification, characterisation and treatment / _cEmma Gabriel.
264		1	_aCork : _bCork Institute of Technology, _c2016.
300			_axi, 204 pages : _bcolor illustrations ; _c30 cm
336			_atext _btxt _2rdacontent
337			_aunmediated _bn _2rdamedia
338			_avolume _bnc _2rdacarrier
490		0	_aPh.D - Biological Sciences
500			_aThe work presented in this thesis focuses on clinically significant staphylococci (with an emphasis on coagulase-negative staphylococci) in terms of their isolation, identification, characterisation and biocontrol. CoNS are increasingly being recognised as true nosocomial pathogens yet remain under-characterised, particularly from an Irish clinical perspective. We examined a large cohort of clinically-derived CoNS, isolated from blood (n=135), identifying them to species level. Extensive antibiotic resistance against nine clinically-relevant antibiotics was recorded. Additionally, widespread biofilm forming capabilities associated with increased virulence was detected both phenotypically and genotypically, We identified multiple species of CoNS in circulation in an Irish healthcare setting, and determined valuable insight into their virulence potential. Consequently, a need for their rapid identification to species level upon isolation from blood should be supported. Furthermore, MALDI-TOF MS was compared against 16S rRNA typing, and proposed as a cost- and time-efficient alternative to conventional phenotypic clinical based tests for the identification of Staphylococcus epidermidis (the most frequently isolated and virulent of the CoNS group). From an Irish perspective, we reported the earliest incidence of meticillin resistant S. epidermidis clinical isolates to demonstrate both mutational and transmissible mechanisms of linezolid resistance. This characterisation has provided significant epidemiological insight into this rare yet emerging resistance to an important anti-staphylococcal antibiotic. Furthermore, a novel HRM-PCR assay was designed to detect S. epidermidis isolates resistant to linezolid. We delivered a faster more reliable means of detecting the G2576T point mutation (most frequently encountered mechanism of linezolid resistance). This work can be used to more rapidly detect and perhaps prevent further dissemination of linezolid resistance in clinical settings. We carried out a study, the first of its kind in Ireland, which reported the superior ability of culture from sonicate fluid combined with MALDI-TOF MS to detect periprosthetic joint infection (PJI), compared with conventional methods in current clinical practise. Notably, two hospitals are looking into changing laboratory protocol based on our findings. We reported that 16S rRNA screening of sonicate fluid from resected hip and knee prostheses allowed the identification of 'true' aseptic failure as opposed to clinically-undetected PJI, which if implemented for routine in diagnostic laboratories could circumvent the unnecessary administration of broad spectrum antibiotics. We found the application of 16S-cloning and sequencing from sonicate to further enhance the detection rate of bacteria from the resected prosthetic joints. Additionally, the microbial diversity associated with failed hip and knee prostheses was revealed, another first from an Irish perspective. Finally, a bacteriophage (phage) demonstrating excellent staphylolytic activity was isolated and purified. The results here are significant as phage B.1 proved highly lytic against S. aureus PJI isolates and meticillin-resistant S. aureus (MRSA) strains from the National MRSA reference bank (2008), all of which expressed resistance to multiple antibiotics. While preliminary, we have exhibited the potential for phage as an adjunct or alternative to antibiotics for the treatment of infections such as PJIs, quelling the spread of multidrug resistance - (Abstract)
502			_aThesis _b(PhD) - _cCork Institute of Technology, _d2016.
504			_aBibliography: (pages 175-203)
650		0	_942873 _aStaphylococcal infections
650		0	_aProsthesis _941542
650		0	_952169 _aBacteriophages
650		0	_935554 _aCommunicable diseases
650		0	_938058 _aHealth facilities _zIreland
650		0	_aAntibiotics _933957
942			_2ddc