Maureen Boost - Academia.edu (original) (raw)

Papers by Maureen Boost

Antibiotics, Nov 27, 2023

Antimicrobial Resistance & Infection Control, 2017

treat MDRGNB infections. This finding pointed that strict antibiotic policies were required to wo... more treat MDRGNB infections. This finding pointed that strict antibiotic policies were required to work out the issue of emerging MDR-GNB infections.

Biosensors and Bioelectronics, Mar 1, 2014

ABSTRACT We report the use of gold nanoparticles (Au NPs) for direct colourimetric polymerase cha... more ABSTRACT We report the use of gold nanoparticles (Au NPs) for direct colourimetric polymerase chain reaction (PCR) detection of methicillin-resistant Staphylococcus aureus (MRSA) in clinical specimens. The colourimetric assay comprised of 2 Au NP probes functionalized with Staphylococcus aureus 23S rRNA- and mecA-specific oligonucleotides. In this study, 72 clinical samples were tested, which included positive blood culture (n=23), urine (n=8), respiratory samples (n=23), as well as wound swabs, pus and body fluid (n=18). Results were recorded qualitatively by direct visual examination and quantitatively by UV-vis spectrophotometry. Using conventional bacterial culture as the gold standard, the sensitivity, specificity, positive predictive value and negative predictive value of this colourimetric assay were 97.14%, 91.89%, 91.89% and 97.14%, respectively, which were comparable to that of commercial real-time PCR assays with a lower cost per reaction. Our assay also showed good agreement with bacterial culture (κ=0.889). The overall detection limit was 500ng target amplicon, which was comparable to or better than other similar Au NP biosensors. Interestingly, our data revealed the possible relationship between Au NP probe-target hybridization site and assay performance, which might provide hints for design of the Au NP biosensors for nucleic acid detection. To conclude, our study was the first report on the use of Au NP colourimetric assay for direct detection of MRSA in various types of clinical specimens. Further evaluation of the assay is needed in large-scale trials which can also allow for some modifications to streamline the procedures for routine use.

2009-2010 > Academic research: refereed > Refereed conference pape

2004-2005 > Academic research: refereed > Refereed conference pape

Contact Lens and Anterior Eye, Dec 1, 2018

This study investigated the efficacy of a novel povidone-iodine based disinfection solution for r... more This study investigated the efficacy of a novel povidone-iodine based disinfection solution for rigid gas permeable (RGP) lenses compared to three other currently available multipurpose and hydrogen peroxide solutions. Bactericidal and fungicidal activities were assessed using ISO 14729 reference methods, whilst amoebicidal properties were evaluated using an automated viability counter. All solutions were also assessed for long term storage stability over a 3-month period. The FDA guidelines were adequately achieved by all solutions tested and 3-month storage did not affect their activity against bacterial and fungal agents. Activity against Acanthamoeba castellani trophozoites reached 1-log reduction for the povidone-iodine solution and approached this level for the remaining solutions. Activity against cysts was somewhat reduced and ranged from 78 to 86% reduction in viability. A povidone-iodine based solution, which may offer advantages as resistance to this agent has not been demonstrated and it lacks toxicity, provided equivalent antimicrobial activity to other RGP solutions.

$Research paper thumbnail of Categorisation of myopia progression by change in refractive error and axial elongation and their impact on benefit of myopia control using orthokeratology$

PLOS ONE, Dec 29, 2020

To compare the value of pre-treatment axial elongation (AE) and changes in refractive sphere (M c... more To compare the value of pre-treatment axial elongation (AE) and changes in refractive sphere (M change) for predicting the success in orthokeratology (ortho-k), in order to better identify suitable candidates for myopia control. Methods This study further analysed the data of 66 subjects receiving 7-month ortho-k treatment, following a 7-month observation period, during which single-vision spectacles were worn. Rate of myopia progression was determined by AE and M change and subjects categorised as slow, moderate, or rapid progressors based on these changes. Outcomes of myopia control, based on the AE reduction after ortho-k, were classified as 'ineffectual', 'clinically insignificant', or 'beneficial'. Results Of the 20 subjects, initially categorised as slow by AE and, of whom 95% were similarly categorised by M change, none benefitted from ortho-k. In contrast, of the 22 subjects with moderate AE, 77% and 23% displaying slow and moderate M change, respectively, the majority (73%) benefitted from ortho-k lens wear. The 24 subjects with rapid AE were poorly identified by M change, with only 21% correctly categorised. The vast majority of rapid progressors showed significant benefit after ortho-k. Conclusion Progression of AE is a good indicator of subsequent success of ortho-k treatment. Delaying commencement of therapy is prudent for children with slow progression as results indicate that they would be unlikely to benefit from this intervention. As change in refractive error frequently underestimates rapid progression of AE, its value for identifying appropriate candidates for myopia control is poor.

Contact Lens and Anterior Eye, Feb 1, 2023

Contact Lens and Anterior Eye, Dec 1, 2021

Purpose. To compare lens cleaning routines using a povidone iodine-based rigid lens disinfecting ... more Purpose. To compare lens cleaning routines using a povidone iodine-based rigid lens disinfecting solution and its effect on conjunctival colonisation, and lens and lens case contamination. Methods. Participants, aged 6-10 years, receiving orthokeratology treatment were randomised to four lens cleaning routines: with and without the use of daily and/or weekly cleaners, which were performed by their parents. Conjunctival colonisation was compared before lens wear and at 1-, 3-, and 6-month after commencement of lens wear. Contamination of lenses and lens cases was investigated at these times. Organisms were identified using MALDI-TOF mass spectrometry. Results. Of the 76 participants who completed the study, conjunctival colonization was present in 24 (32%) at baseline. Of the remaining 52 participants, 34 consistently yielded no growth. Participants positive at baseline were statistically more likely to be colonized after commencement of lens wear (p=0.020). Overall, colonization rate was reduced to 15% (11/72) after 6-month lens wear, which reached significance for initially colonized participants (p < 0.001). Few cultures yielded potential ocular pathogens, with notably no Pseudomonas aeruginosa. Contamination rates of both lenses and lens cases were also low,

Zoonoses and Public Health, Mar 12, 2012

SummaryThis study describes the isolation and characterization of methicillin‐resistant Staphyloc... more SummaryThis study describes the isolation and characterization of methicillin‐resistant Staphylococcus aureus (MRSA) from slaughtered pigs sampled from local markets in Hong Kong. The nares of 400 slaughtered pigs were cultured and MRSA isolates characterized for the presence of antibiotic‐resistance determinants, toxins and SCCmec and spa types using PCR. Clonality was investigated using PFGE and MLST. The prevalence of MRSA colonization of slaughter pigs was 39.3%, the majority (92%) harbouring SCCmec type IVb. Of the 157 samples yielding MRSA, 13 had two distinct MRSA strains present. Spa type t899 was predominant, with only 5/170 isolates displaying closely related types (t4474, t1939, t2922 and t5390). PFGE with sma1 and MLST confirmed the strains as ST9. Most isolates were multidrug resistant. Tetracycline resistance (97%) was mainly attributable to tet(K) with only 3% of isolates additionally harbouring tet(M). Resistance to erythromycin (89%) and chloramphenicol (71%) was associated with the presence of erm(C), and fex(A), respectively. No strains carried cfr and there was no resistance to linezolid, although minimum inhibitory concentration (MICs) were close to the resistance break point. Resistance to clindamycin (99%), ciprofloxacin(78%), quinopristin–dalfopristin (44%) and cotrimoxazole (32%) was common, but remained low for fusidic acid (4%) and rifampicin (2%). All strains were negative for PVL, exfoliative, and enterotoxins. This survey confirmed the uniformity of MRSA isolates in pigs from several regions of China, in contrast to more diversified characteristics reported in European studies. Colonization rates were higher than previously reported. Isolates were resistant to a wide range of antibiotics, but resistance was not detected to linezolid, nitrofurantoin, vancomycin or tigecycline. Although the clinical importance of ST9 in humans is uncertain, continued surveillance, in particular of those occupationally‐exposed, is recommended.

Epidemiology and Infection, Aug 3, 2007

Case reports have indicated transmission of Staphylococcus aureus between humans and pets. We inv... more Case reports have indicated transmission of Staphylococcus aureus between humans and pets. We investigated associations between level of contact between dog and owner, and S. aureus colonization. In a cross-sectional study, nasal carriage and antibiotic susceptibility of S. aureus was determined for 830 dogs and 736 owners. Relatedness of isolates was investigated using antibiograms and pulsed-field gel electrophoresis (PFGE). Associations between carriage and demographics or amount of contact between owners and dogs were documented. S. aureus was isolated in 24% of humans and 8. 8% of dogs. Antibiotic resistance was significantly more common in canine isolates. Of 17 owner/dog colonized pairs, six were indistinguishable by PFGE. Colonization of dogs was not associated with close human contact, but was strongly associated with health-care occupations (OR 3. 29, 95% CI 1. 49-7. 26, P=0. 002). In outbreak situations health-care workers' pets should be considered as a source of S. aureus. High rates of resistance indicate increased monitoring of antibiotic use in veterinary practice is needed.

2003-2004 > Academic research: refereed > Refereed conference pape

2006-2007 > Academic research: refereed > Refereed conference pape

PubMed, Dec 1, 2015

K e y M e s s a g e s 1. There is a high level of contamination of pig carcasses in Hong Kong wit... more K e y M e s s a g e s 1. There is a high level of contamination of pig carcasses in Hong Kong with multi-drug resistant methicillin-resistant Staphylococcus aureus (MRSA) ST9. 2. Personnel occupationally exposed to pigs and pig carcasses are at risk of colonisation and possible infection. 3. Whilst the clinical significance of porcine MRSA ST9 is unclear, there is a need for continued surveillance of this potential reservoir of MRSA. 4. Butchers should be encouraged to wear gloves

European Journal of Clinical Microbiology & Infectious Diseases, Aug 26, 2015

This study investigated the association between the presence of staphylococcal enterotoxin (SE) g... more This study investigated the association between the presence of staphylococcal enterotoxin (SE) genes and nasal carriage status, and determined temporal changes in the prevalence of these genes in Staphylococcus aureus strains isolated from healthy carriers between 2002 and 2011. Three large samples of food handlers recruited in 2002, 2003 and 2011 were nasally sampled on two occasions to determine S. aureus colonisation status. Those carrying the same spa type on both occasions were defined as persistent carriers. Genes for SEs SEA-SEU were amplified and associations between carriage status and presence of SE genes were investigated. Although 80 % of nasal isolates harboured at least one SE gene over the sampling period, persistent carriers were significantly more likely to harbour enterotoxigenic S. aureus than transiently colonised subjects [odds ratio (OR) 2.52-3.06]. Strains from persistent carriers more commonly harboured sea, seb and sem. The prevalence of classical SE genes and sej, sem, sen, seo, seq and ses was stable over time, but seh, sel, sep, ser, set and selu increased significantly. Increased toxigenicity of isolates from persistent carriers is consistent with the elevated antibody levels to classical SEs previously reported in persistent carriers, supporting the hypothesis that superantigen production in the nasal cavity may enhance colonisation.

Awarded a prize by ANSORP for best poster of conference2000-2001 > Academic research: refereed... more Awarded a prize by ANSORP for best poster of conference2000-2001 > Academic research: refereed > Refereed conference pape

2005-2006 > Academic research: refereed > Refereed conference pape

Advances in ophthalmology practice and research, Dec 1, 2021