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Stephanie L Watson - One of the best experts on this subject based on the ideXlab platform.

  • Bacterial Ocular Surveillance System (BOSS) Sydney, Australia 2017-2018
    Communicable Diseases Intelligence, 2020
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Benjamin H Armstrong, C R Robert George, Pauline Khoo, Monica M Lahra
    Abstract:

    This study investigated antimicrobial resistance (AMR) profiles from a cohort of patients with bacterial keratitis treated at Sydney Eye Hospital, 1 January 2017 – 31 December 2018. These AMR profiles were analysed in the context of the current Australian empiric regimens for topical therapy: ciprofloxacin/ofloxacin monotherapy versus combination therapy of Cefalotin/cephazolin plus gentamicin. At our Centre, combinations of (i) chloramphenicol plus gentamicin and (ii) chloramphenicol plus ciprofloxacin are alternatively used, so were also analysed. Three hundred and seventy-four isolates were cultured prospectively: 280/374 (75%) were gram positive, and 94/374 (25%) were gram negative. Coagulase-negative staphylococci comprised 173/374 (46%). Isolates included <i>Staphylococcus aureus</i> (n = 43/374) 11%; <i>Streptococcus pneumoniae</i> (n = 14/374) 3.7%; and <i>Pseudomonas aeruginosa</i> (n = 50/374) 13%. Statistical comparison was performed. There was no significant difference between cover provided either of the current Australian recommendations: ciprofloxacin/ofloxacin vs Cefalotin/cephazolin plus gentamicin (5.3% vs 4.8%, respectively; <i>p</i> = 0.655). However, the combination of chloramphenicol plus an anti-pseudomonal agent (ciprofloxacin/ofloxacin or gentamicin) had significantly improved cover. Chloramphenicol plus gentamicin was superior to ciprofloxacin/ofloxacin (1.9% vs 5.3% resistance respectively; <i>p</i> = 0.007), and Cefalotin/cephazolin plus gentamicin (1.9% vs 4.8%; <i>p</i> = 0.005). Chloramphenicol plus ciprofloxacin was superior to ciprofloxacin/ofloxacin monotherapy (1.3% vs 5.3%; <i>p</i> ≤ 0.001), and to Cefalotin/cephazolin plus gentamicin (1.3% vs 4.8%; <i>p</i> = 0.003). Chloramphenicol plus gentamicin versus chloramphenicol plus ciprofloxacin/ofloxacin were equivalent (<i>p</i> = 0.48). There was no demonstrated in vitro superiority of either the current empiric antibiotic regimens. For our setting, for bacterial keratitis, chloramphenicol in combination offered superior in vitro cover. Broadened surveillance for ocular AMR is urgently needed across jurisdictions.

  • Antimicrobial resistance trends in bacterial keratitis over 5 years in Sydney, Australia.
    Clinical & experimental ophthalmology, 2019
    Co-Authors: Maria Cabrera-aguas, C R Robert George, Pauline Khoo, Monica M Lahra, Stephanie L Watson
    Abstract:

    Importance Antimicrobial resistance (AMR) patterns in bacterial keratitis may fluctuate in a geographic location over time. Background To investigate any change in AMR patterns in Sydney, Australia. Design Retrospective case series. Participants All patients with microbial keratitis who underwent a corneal scrape and culture from 2012 to 2016 at the Sydney Eye Hospital. Methods Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified organisms. The Calibrated Dichotomous Susceptibility method determined antibiotic susceptibilities. Main outcome measures Isolated organisms and antibiotic susceptibilities. Results There were 1084 corneal scrapes from 957 patients. The mean age was 54 years (range 18-100) and 52% were male. Cultures were positive in 711 of 1084 scrapes (66%), with 884 organisms identified. Of the bacteria isolated, 685 of 884 (78%) were Gram-positive and 199 of 884 (22%) were Gram-negative. Overall, the most common bacteria were coagulase-negative Staphylococci (CoNS) (405/884, 46%). Methicillin-resistance was detected in 7% of Staphylococcus aureus isolates (7/103). Methicillin-resistance in CoNS (ie, also Cefalotin resistance) was reported in 19% of isolates and ciprofloxacin 8%. For methicillin-sensitive S aureus (MSSA), 5% of isolates were resistant to ciprofloxacin. For Corynebacterium spp., 34% of isolates were resistant to chloramphenicol and 9% to ciprofloxacin. The most common Gram-negative bacteria was Pseudomonas aeruginosa (109/199, 55%). One case was resistant to ciprofloxacin. Conclusions and relevance Coagulase-negative staphylococcal species were the most frequently suspected of causing bacterial keratitis. Increased resistance to Cefalotin was identified for CoNS and to ciprofloxacin for Corynebacterium spp., MSSA and P aeruginosa compared to a previous study in Sydney in 2002 to 2003.

  • Keratitis antimicrobial resistance surveillance program, Sydney, Australia: 2016 Annual Report.
    Clinical & experimental ophthalmology, 2018
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Pauline Khoo, Ryanbi Pratama, Trine Gulholm, Jasmin El-nasser, Monica M Lahra
    Abstract:

    IMPORTANCE Antimicrobial resistance data from bacterial keratitis in Australia are lacking. BACKGROUND Antimicrobial resistance is a global health threat. Bacterial keratitis is an ophthalmic emergency requiring immediate and effective treatment. DESIGN Retrospective cohort study of bacterial isolates and antibiotic susceptibility profiles at a quaternary hospital in Sydney, Australia. PARTICIPANTS Two hundred and twenty-four corneal scrapes from patients from January 1 to December 31, 2016. METHODS Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified bacteria. The Calibrated Dichotomous Sensitivity (CDS) method determined antibiotic susceptibilities. MAIN OUTCOME MEASURES Isolated organisms and antibiotic susceptibilities. RESULTS One hundred and sixty-eight scrapes of 224 (75%) were culture positive. One hundred and thirty-one patients had a single organism isolated and 21 had mixed bacterial growth. Of the 157 organisms isolated, 131 (83%) were Gram-positive and 27 (17%) Gram-negative. Of the Gram-positive organisms, 75 (57%) were coagulase-negative Staphylococci (CoNS), 15 (11%) Staphylococcus aureus (including one methicillin-resistant Staphylococcus aureus [MRSA]) and 8 (6%) Corynebacterium spp. Of the Gram-negative organisms, 15 (58%) were Pseudomonas aeruginosa. With methicillin-sensitive Staphylococcus aureus (MSSA) resistance to chloramphenicol was 21%, ciprofloxacin 7% and gentamicin 7%. With CoNS resistance to Cefalotin was 9%, gentamicin 9% and ciprofloxacin 9%. With Corynebacterium spp. resistance was 40% to Cefalotin, chloramphenicol 25% and ciprofloxacin 14%. CONCLUSIONS AND RELEVANCE Staphyloccocus spp. and Pseudomonas spp. were the most common microorganisms isolated. There was low resistance to Cefalotin and ciprofloxacin for these isolates. More than 90% of these would be covered by current therapeutic recommendations for empiric therapy in Australia.

Monica M Lahra - One of the best experts on this subject based on the ideXlab platform.

  • Bacterial Ocular Surveillance System (BOSS) Sydney, Australia 2017-2018
    Communicable Diseases Intelligence, 2020
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Benjamin H Armstrong, C R Robert George, Pauline Khoo, Monica M Lahra
    Abstract:

    This study investigated antimicrobial resistance (AMR) profiles from a cohort of patients with bacterial keratitis treated at Sydney Eye Hospital, 1 January 2017 – 31 December 2018. These AMR profiles were analysed in the context of the current Australian empiric regimens for topical therapy: ciprofloxacin/ofloxacin monotherapy versus combination therapy of Cefalotin/cephazolin plus gentamicin. At our Centre, combinations of (i) chloramphenicol plus gentamicin and (ii) chloramphenicol plus ciprofloxacin are alternatively used, so were also analysed. Three hundred and seventy-four isolates were cultured prospectively: 280/374 (75%) were gram positive, and 94/374 (25%) were gram negative. Coagulase-negative staphylococci comprised 173/374 (46%). Isolates included <i>Staphylococcus aureus</i> (n = 43/374) 11%; <i>Streptococcus pneumoniae</i> (n = 14/374) 3.7%; and <i>Pseudomonas aeruginosa</i> (n = 50/374) 13%. Statistical comparison was performed. There was no significant difference between cover provided either of the current Australian recommendations: ciprofloxacin/ofloxacin vs Cefalotin/cephazolin plus gentamicin (5.3% vs 4.8%, respectively; <i>p</i> = 0.655). However, the combination of chloramphenicol plus an anti-pseudomonal agent (ciprofloxacin/ofloxacin or gentamicin) had significantly improved cover. Chloramphenicol plus gentamicin was superior to ciprofloxacin/ofloxacin (1.9% vs 5.3% resistance respectively; <i>p</i> = 0.007), and Cefalotin/cephazolin plus gentamicin (1.9% vs 4.8%; <i>p</i> = 0.005). Chloramphenicol plus ciprofloxacin was superior to ciprofloxacin/ofloxacin monotherapy (1.3% vs 5.3%; <i>p</i> ≤ 0.001), and to Cefalotin/cephazolin plus gentamicin (1.3% vs 4.8%; <i>p</i> = 0.003). Chloramphenicol plus gentamicin versus chloramphenicol plus ciprofloxacin/ofloxacin were equivalent (<i>p</i> = 0.48). There was no demonstrated in vitro superiority of either the current empiric antibiotic regimens. For our setting, for bacterial keratitis, chloramphenicol in combination offered superior in vitro cover. Broadened surveillance for ocular AMR is urgently needed across jurisdictions.

  • Antimicrobial resistance trends in bacterial keratitis over 5 years in Sydney, Australia.
    Clinical & experimental ophthalmology, 2019
    Co-Authors: Maria Cabrera-aguas, C R Robert George, Pauline Khoo, Monica M Lahra, Stephanie L Watson
    Abstract:

    Importance Antimicrobial resistance (AMR) patterns in bacterial keratitis may fluctuate in a geographic location over time. Background To investigate any change in AMR patterns in Sydney, Australia. Design Retrospective case series. Participants All patients with microbial keratitis who underwent a corneal scrape and culture from 2012 to 2016 at the Sydney Eye Hospital. Methods Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified organisms. The Calibrated Dichotomous Susceptibility method determined antibiotic susceptibilities. Main outcome measures Isolated organisms and antibiotic susceptibilities. Results There were 1084 corneal scrapes from 957 patients. The mean age was 54 years (range 18-100) and 52% were male. Cultures were positive in 711 of 1084 scrapes (66%), with 884 organisms identified. Of the bacteria isolated, 685 of 884 (78%) were Gram-positive and 199 of 884 (22%) were Gram-negative. Overall, the most common bacteria were coagulase-negative Staphylococci (CoNS) (405/884, 46%). Methicillin-resistance was detected in 7% of Staphylococcus aureus isolates (7/103). Methicillin-resistance in CoNS (ie, also Cefalotin resistance) was reported in 19% of isolates and ciprofloxacin 8%. For methicillin-sensitive S aureus (MSSA), 5% of isolates were resistant to ciprofloxacin. For Corynebacterium spp., 34% of isolates were resistant to chloramphenicol and 9% to ciprofloxacin. The most common Gram-negative bacteria was Pseudomonas aeruginosa (109/199, 55%). One case was resistant to ciprofloxacin. Conclusions and relevance Coagulase-negative staphylococcal species were the most frequently suspected of causing bacterial keratitis. Increased resistance to Cefalotin was identified for CoNS and to ciprofloxacin for Corynebacterium spp., MSSA and P aeruginosa compared to a previous study in Sydney in 2002 to 2003.

  • Keratitis antimicrobial resistance surveillance program, Sydney, Australia: 2016 Annual Report.
    Clinical & experimental ophthalmology, 2018
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Pauline Khoo, Ryanbi Pratama, Trine Gulholm, Jasmin El-nasser, Monica M Lahra
    Abstract:

    IMPORTANCE Antimicrobial resistance data from bacterial keratitis in Australia are lacking. BACKGROUND Antimicrobial resistance is a global health threat. Bacterial keratitis is an ophthalmic emergency requiring immediate and effective treatment. DESIGN Retrospective cohort study of bacterial isolates and antibiotic susceptibility profiles at a quaternary hospital in Sydney, Australia. PARTICIPANTS Two hundred and twenty-four corneal scrapes from patients from January 1 to December 31, 2016. METHODS Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified bacteria. The Calibrated Dichotomous Sensitivity (CDS) method determined antibiotic susceptibilities. MAIN OUTCOME MEASURES Isolated organisms and antibiotic susceptibilities. RESULTS One hundred and sixty-eight scrapes of 224 (75%) were culture positive. One hundred and thirty-one patients had a single organism isolated and 21 had mixed bacterial growth. Of the 157 organisms isolated, 131 (83%) were Gram-positive and 27 (17%) Gram-negative. Of the Gram-positive organisms, 75 (57%) were coagulase-negative Staphylococci (CoNS), 15 (11%) Staphylococcus aureus (including one methicillin-resistant Staphylococcus aureus [MRSA]) and 8 (6%) Corynebacterium spp. Of the Gram-negative organisms, 15 (58%) were Pseudomonas aeruginosa. With methicillin-sensitive Staphylococcus aureus (MSSA) resistance to chloramphenicol was 21%, ciprofloxacin 7% and gentamicin 7%. With CoNS resistance to Cefalotin was 9%, gentamicin 9% and ciprofloxacin 9%. With Corynebacterium spp. resistance was 40% to Cefalotin, chloramphenicol 25% and ciprofloxacin 14%. CONCLUSIONS AND RELEVANCE Staphyloccocus spp. and Pseudomonas spp. were the most common microorganisms isolated. There was low resistance to Cefalotin and ciprofloxacin for these isolates. More than 90% of these would be covered by current therapeutic recommendations for empiric therapy in Australia.

Maria Cabrera-aguas - One of the best experts on this subject based on the ideXlab platform.

  • Bacterial Ocular Surveillance System (BOSS) Sydney, Australia 2017-2018
    Communicable Diseases Intelligence, 2020
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Benjamin H Armstrong, C R Robert George, Pauline Khoo, Monica M Lahra
    Abstract:

    This study investigated antimicrobial resistance (AMR) profiles from a cohort of patients with bacterial keratitis treated at Sydney Eye Hospital, 1 January 2017 – 31 December 2018. These AMR profiles were analysed in the context of the current Australian empiric regimens for topical therapy: ciprofloxacin/ofloxacin monotherapy versus combination therapy of Cefalotin/cephazolin plus gentamicin. At our Centre, combinations of (i) chloramphenicol plus gentamicin and (ii) chloramphenicol plus ciprofloxacin are alternatively used, so were also analysed. Three hundred and seventy-four isolates were cultured prospectively: 280/374 (75%) were gram positive, and 94/374 (25%) were gram negative. Coagulase-negative staphylococci comprised 173/374 (46%). Isolates included <i>Staphylococcus aureus</i> (n = 43/374) 11%; <i>Streptococcus pneumoniae</i> (n = 14/374) 3.7%; and <i>Pseudomonas aeruginosa</i> (n = 50/374) 13%. Statistical comparison was performed. There was no significant difference between cover provided either of the current Australian recommendations: ciprofloxacin/ofloxacin vs Cefalotin/cephazolin plus gentamicin (5.3% vs 4.8%, respectively; <i>p</i> = 0.655). However, the combination of chloramphenicol plus an anti-pseudomonal agent (ciprofloxacin/ofloxacin or gentamicin) had significantly improved cover. Chloramphenicol plus gentamicin was superior to ciprofloxacin/ofloxacin (1.9% vs 5.3% resistance respectively; <i>p</i> = 0.007), and Cefalotin/cephazolin plus gentamicin (1.9% vs 4.8%; <i>p</i> = 0.005). Chloramphenicol plus ciprofloxacin was superior to ciprofloxacin/ofloxacin monotherapy (1.3% vs 5.3%; <i>p</i> ≤ 0.001), and to Cefalotin/cephazolin plus gentamicin (1.3% vs 4.8%; <i>p</i> = 0.003). Chloramphenicol plus gentamicin versus chloramphenicol plus ciprofloxacin/ofloxacin were equivalent (<i>p</i> = 0.48). There was no demonstrated in vitro superiority of either the current empiric antibiotic regimens. For our setting, for bacterial keratitis, chloramphenicol in combination offered superior in vitro cover. Broadened surveillance for ocular AMR is urgently needed across jurisdictions.

  • Antimicrobial resistance trends in bacterial keratitis over 5 years in Sydney, Australia.
    Clinical & experimental ophthalmology, 2019
    Co-Authors: Maria Cabrera-aguas, C R Robert George, Pauline Khoo, Monica M Lahra, Stephanie L Watson
    Abstract:

    Importance Antimicrobial resistance (AMR) patterns in bacterial keratitis may fluctuate in a geographic location over time. Background To investigate any change in AMR patterns in Sydney, Australia. Design Retrospective case series. Participants All patients with microbial keratitis who underwent a corneal scrape and culture from 2012 to 2016 at the Sydney Eye Hospital. Methods Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified organisms. The Calibrated Dichotomous Susceptibility method determined antibiotic susceptibilities. Main outcome measures Isolated organisms and antibiotic susceptibilities. Results There were 1084 corneal scrapes from 957 patients. The mean age was 54 years (range 18-100) and 52% were male. Cultures were positive in 711 of 1084 scrapes (66%), with 884 organisms identified. Of the bacteria isolated, 685 of 884 (78%) were Gram-positive and 199 of 884 (22%) were Gram-negative. Overall, the most common bacteria were coagulase-negative Staphylococci (CoNS) (405/884, 46%). Methicillin-resistance was detected in 7% of Staphylococcus aureus isolates (7/103). Methicillin-resistance in CoNS (ie, also Cefalotin resistance) was reported in 19% of isolates and ciprofloxacin 8%. For methicillin-sensitive S aureus (MSSA), 5% of isolates were resistant to ciprofloxacin. For Corynebacterium spp., 34% of isolates were resistant to chloramphenicol and 9% to ciprofloxacin. The most common Gram-negative bacteria was Pseudomonas aeruginosa (109/199, 55%). One case was resistant to ciprofloxacin. Conclusions and relevance Coagulase-negative staphylococcal species were the most frequently suspected of causing bacterial keratitis. Increased resistance to Cefalotin was identified for CoNS and to ciprofloxacin for Corynebacterium spp., MSSA and P aeruginosa compared to a previous study in Sydney in 2002 to 2003.

  • Keratitis antimicrobial resistance surveillance program, Sydney, Australia: 2016 Annual Report.
    Clinical & experimental ophthalmology, 2018
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Pauline Khoo, Ryanbi Pratama, Trine Gulholm, Jasmin El-nasser, Monica M Lahra
    Abstract:

    IMPORTANCE Antimicrobial resistance data from bacterial keratitis in Australia are lacking. BACKGROUND Antimicrobial resistance is a global health threat. Bacterial keratitis is an ophthalmic emergency requiring immediate and effective treatment. DESIGN Retrospective cohort study of bacterial isolates and antibiotic susceptibility profiles at a quaternary hospital in Sydney, Australia. PARTICIPANTS Two hundred and twenty-four corneal scrapes from patients from January 1 to December 31, 2016. METHODS Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified bacteria. The Calibrated Dichotomous Sensitivity (CDS) method determined antibiotic susceptibilities. MAIN OUTCOME MEASURES Isolated organisms and antibiotic susceptibilities. RESULTS One hundred and sixty-eight scrapes of 224 (75%) were culture positive. One hundred and thirty-one patients had a single organism isolated and 21 had mixed bacterial growth. Of the 157 organisms isolated, 131 (83%) were Gram-positive and 27 (17%) Gram-negative. Of the Gram-positive organisms, 75 (57%) were coagulase-negative Staphylococci (CoNS), 15 (11%) Staphylococcus aureus (including one methicillin-resistant Staphylococcus aureus [MRSA]) and 8 (6%) Corynebacterium spp. Of the Gram-negative organisms, 15 (58%) were Pseudomonas aeruginosa. With methicillin-sensitive Staphylococcus aureus (MSSA) resistance to chloramphenicol was 21%, ciprofloxacin 7% and gentamicin 7%. With CoNS resistance to Cefalotin was 9%, gentamicin 9% and ciprofloxacin 9%. With Corynebacterium spp. resistance was 40% to Cefalotin, chloramphenicol 25% and ciprofloxacin 14%. CONCLUSIONS AND RELEVANCE Staphyloccocus spp. and Pseudomonas spp. were the most common microorganisms isolated. There was low resistance to Cefalotin and ciprofloxacin for these isolates. More than 90% of these would be covered by current therapeutic recommendations for empiric therapy in Australia.

Pauline Khoo - One of the best experts on this subject based on the ideXlab platform.

  • Bacterial Ocular Surveillance System (BOSS) Sydney, Australia 2017-2018
    Communicable Diseases Intelligence, 2020
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Benjamin H Armstrong, C R Robert George, Pauline Khoo, Monica M Lahra
    Abstract:

    This study investigated antimicrobial resistance (AMR) profiles from a cohort of patients with bacterial keratitis treated at Sydney Eye Hospital, 1 January 2017 – 31 December 2018. These AMR profiles were analysed in the context of the current Australian empiric regimens for topical therapy: ciprofloxacin/ofloxacin monotherapy versus combination therapy of Cefalotin/cephazolin plus gentamicin. At our Centre, combinations of (i) chloramphenicol plus gentamicin and (ii) chloramphenicol plus ciprofloxacin are alternatively used, so were also analysed. Three hundred and seventy-four isolates were cultured prospectively: 280/374 (75%) were gram positive, and 94/374 (25%) were gram negative. Coagulase-negative staphylococci comprised 173/374 (46%). Isolates included <i>Staphylococcus aureus</i> (n = 43/374) 11%; <i>Streptococcus pneumoniae</i> (n = 14/374) 3.7%; and <i>Pseudomonas aeruginosa</i> (n = 50/374) 13%. Statistical comparison was performed. There was no significant difference between cover provided either of the current Australian recommendations: ciprofloxacin/ofloxacin vs Cefalotin/cephazolin plus gentamicin (5.3% vs 4.8%, respectively; <i>p</i> = 0.655). However, the combination of chloramphenicol plus an anti-pseudomonal agent (ciprofloxacin/ofloxacin or gentamicin) had significantly improved cover. Chloramphenicol plus gentamicin was superior to ciprofloxacin/ofloxacin (1.9% vs 5.3% resistance respectively; <i>p</i> = 0.007), and Cefalotin/cephazolin plus gentamicin (1.9% vs 4.8%; <i>p</i> = 0.005). Chloramphenicol plus ciprofloxacin was superior to ciprofloxacin/ofloxacin monotherapy (1.3% vs 5.3%; <i>p</i> ≤ 0.001), and to Cefalotin/cephazolin plus gentamicin (1.3% vs 4.8%; <i>p</i> = 0.003). Chloramphenicol plus gentamicin versus chloramphenicol plus ciprofloxacin/ofloxacin were equivalent (<i>p</i> = 0.48). There was no demonstrated in vitro superiority of either the current empiric antibiotic regimens. For our setting, for bacterial keratitis, chloramphenicol in combination offered superior in vitro cover. Broadened surveillance for ocular AMR is urgently needed across jurisdictions.

  • Antimicrobial resistance trends in bacterial keratitis over 5 years in Sydney, Australia.
    Clinical & experimental ophthalmology, 2019
    Co-Authors: Maria Cabrera-aguas, C R Robert George, Pauline Khoo, Monica M Lahra, Stephanie L Watson
    Abstract:

    Importance Antimicrobial resistance (AMR) patterns in bacterial keratitis may fluctuate in a geographic location over time. Background To investigate any change in AMR patterns in Sydney, Australia. Design Retrospective case series. Participants All patients with microbial keratitis who underwent a corneal scrape and culture from 2012 to 2016 at the Sydney Eye Hospital. Methods Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified organisms. The Calibrated Dichotomous Susceptibility method determined antibiotic susceptibilities. Main outcome measures Isolated organisms and antibiotic susceptibilities. Results There were 1084 corneal scrapes from 957 patients. The mean age was 54 years (range 18-100) and 52% were male. Cultures were positive in 711 of 1084 scrapes (66%), with 884 organisms identified. Of the bacteria isolated, 685 of 884 (78%) were Gram-positive and 199 of 884 (22%) were Gram-negative. Overall, the most common bacteria were coagulase-negative Staphylococci (CoNS) (405/884, 46%). Methicillin-resistance was detected in 7% of Staphylococcus aureus isolates (7/103). Methicillin-resistance in CoNS (ie, also Cefalotin resistance) was reported in 19% of isolates and ciprofloxacin 8%. For methicillin-sensitive S aureus (MSSA), 5% of isolates were resistant to ciprofloxacin. For Corynebacterium spp., 34% of isolates were resistant to chloramphenicol and 9% to ciprofloxacin. The most common Gram-negative bacteria was Pseudomonas aeruginosa (109/199, 55%). One case was resistant to ciprofloxacin. Conclusions and relevance Coagulase-negative staphylococcal species were the most frequently suspected of causing bacterial keratitis. Increased resistance to Cefalotin was identified for CoNS and to ciprofloxacin for Corynebacterium spp., MSSA and P aeruginosa compared to a previous study in Sydney in 2002 to 2003.

  • Keratitis antimicrobial resistance surveillance program, Sydney, Australia: 2016 Annual Report.
    Clinical & experimental ophthalmology, 2018
    Co-Authors: Stephanie L Watson, Barrie J Gatus, Maria Cabrera-aguas, Pauline Khoo, Ryanbi Pratama, Trine Gulholm, Jasmin El-nasser, Monica M Lahra
    Abstract:

    IMPORTANCE Antimicrobial resistance data from bacterial keratitis in Australia are lacking. BACKGROUND Antimicrobial resistance is a global health threat. Bacterial keratitis is an ophthalmic emergency requiring immediate and effective treatment. DESIGN Retrospective cohort study of bacterial isolates and antibiotic susceptibility profiles at a quaternary hospital in Sydney, Australia. PARTICIPANTS Two hundred and twenty-four corneal scrapes from patients from January 1 to December 31, 2016. METHODS Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identified bacteria. The Calibrated Dichotomous Sensitivity (CDS) method determined antibiotic susceptibilities. MAIN OUTCOME MEASURES Isolated organisms and antibiotic susceptibilities. RESULTS One hundred and sixty-eight scrapes of 224 (75%) were culture positive. One hundred and thirty-one patients had a single organism isolated and 21 had mixed bacterial growth. Of the 157 organisms isolated, 131 (83%) were Gram-positive and 27 (17%) Gram-negative. Of the Gram-positive organisms, 75 (57%) were coagulase-negative Staphylococci (CoNS), 15 (11%) Staphylococcus aureus (including one methicillin-resistant Staphylococcus aureus [MRSA]) and 8 (6%) Corynebacterium spp. Of the Gram-negative organisms, 15 (58%) were Pseudomonas aeruginosa. With methicillin-sensitive Staphylococcus aureus (MSSA) resistance to chloramphenicol was 21%, ciprofloxacin 7% and gentamicin 7%. With CoNS resistance to Cefalotin was 9%, gentamicin 9% and ciprofloxacin 9%. With Corynebacterium spp. resistance was 40% to Cefalotin, chloramphenicol 25% and ciprofloxacin 14%. CONCLUSIONS AND RELEVANCE Staphyloccocus spp. and Pseudomonas spp. were the most common microorganisms isolated. There was low resistance to Cefalotin and ciprofloxacin for these isolates. More than 90% of these would be covered by current therapeutic recommendations for empiric therapy in Australia.

Sheree E. Cross - One of the best experts on this subject based on the ideXlab platform.

  • Inadequate antimicrobial prophylaxis during surgery: a study of b-lactam levels during burn debridement
    2014
    Co-Authors: Andrew J. Dalley, Jeffrey Lipman, Bala Venkatesh, Michael Rudd, Michael S. Roberts, Sheree E. Cross
    Abstract:

    Objectives: To determine how long single-dose prophylactic antibiotic regimens for burns surgery maintained plasma concentrations above the MICs for target organisms during surgery. Patients and methods: We monitored antibiotic plasma concentrations in 12 patients (mean+SD 43+ 12 % total burn surface area) throughout debridement surgery after administration of the standard pro-phylactic antibiotic dosing regimens of either 1 g of intravenous Cefalotin or 4.5 g of intravenous piper-acillin/tazobactam. Results: The eschar debridement and grafting procedures ranged in duration from 2.25 to over 8.5 h. The duration of total plasma Cefalotin concentration above an MIC of 0.2 mg/L for Staphylococcus aureus was 6.49+ 2.85 h, whereas the mean duration of total plasma piperacillin concentration above an MIC of 64 mg/L for Pseudomonas aeruginosa was only 1.15+ 0.59 h. None of the patients dosed with piperacillin/tazobactam was adequately protected for the duration of their surgery and adequate prophylaxis was only evident in four of the nine patients administered Cefalotin. Conclusions: These results suggest a need to review antibiotic prophylaxis dosage regimens for burns surgery and the adoption of regimens that will minimize the risk of infection in this high-risk patient group. It is suggested that the antibiotic prophylaxis guideline for burn debridement surgery be modi-fied to include re-dosing or a continuous infusion of b-lactam antibiotics

  • Unbound cephalothin pharmacokinetics in adult burn patients are related to the elapsed time after injury.
    Antimicrobial agents and chemotherapy, 2009
    Co-Authors: Andrew J. Dalley, Jeffrey Lipman, Bala Venkatesh, Michael Rudd, Michael S. Roberts, Renae Deans, Sheree E. Cross
    Abstract:

    Cephalothin (Cefalotin) pharmacokinetics were evaluated for nine severely burned patients (42% ± 9% mean burn areas) and five healthy volunteers by using non-plasma-protein-bound concentration-time profiles. Burn patients gave increased mean residence times (36%) and reduced total clearances (25%). Mean residence times and distribution volumes increased between 1 and 4 days posttrauma, suggesting that burn patient pharmacokinetics change during the initial fluid resuscitation phase of treatment.

  • Inadequate antimicrobial prophylaxis during surgery: a study of β-lactam levels during burn debridement
    The Journal of antimicrobial chemotherapy, 2007
    Co-Authors: Andrew J. Dalley, Jeffrey Lipman, Bala Venkatesh, Michael Rudd, Michael S. Roberts, Sheree E. Cross
    Abstract:

    Objectives: To determine how long single-dose prophylactic antibiotic regimens for burns surgery maintained plasma concentrations above the MICs for target organisms during surgery. Patients and methods: We monitored antibiotic plasma concentrations in 12 patients (mean +/- SD 43 +/- 12% total burn surface area) throughout debridement surgery after administration of the standard prophylactic antibiotic dosing regimens of either 1 g of intravenous Cefalotin or 4.5 g of intravenous piperacillin/tazobactam. Results: The eschar debridement and grafting procedures ranged in duration from 2.25 to over 8.5 h. The duration of total plasma Cefalotin concentration above an MIC of 0.2 mg/L for Staphylococcus aureus was 6.49 +/- 2.85 h, whereas the mean duration of total plasma piperacillin concentration above an MIC of 64 mg/L for Pseudomonas aeruginosa was only 1.15 +/- 0.59 h. None of the patients dosed with piperacillin/tazobactam was adequately protected for the duration of their surgery and adequate prophylaxis was only evident in four of the nine patients administered Cefalotin. Conclusions: These results suggest a need to review antibiotic prophylaxis dosage regimens for burns surgery and the adoption of regimens that will minimize the risk of infection in this high-risk patient group. It is suggested that the antibiotic prophylaxis guideline for burn debridement surgery be modified to include re-dosing or a continuous infusion of P-lactam antibiotics.