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Lo CKF, Sritharan A, Zhang J, Li N, Zhang C, Wang F, Loeb M, Bai AD. Clinical significance of cefazolin inoculum effect in serious MSSA infections: a systematic review. JAC Antimicrob Resist 2024; 6:dlae069. [PMID: 38716403 PMCID: PMC11073751 DOI: 10.1093/jacamr/dlae069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/10/2024] [Indexed: 06/29/2024] Open
Abstract
Background The cefazolin inoculum effect (CzIE) is a phenomenon whereby some MSSA isolates demonstrate resistance to cefazolin when a high bacterial inoculum is used for susceptibility testing. The clinical significance of this phenotypic phenomenon remains unclear. We conducted a systematic review to answer the following question: In patients with serious MSSA infection treated with cefazolin, does infection due to CzIE-positive MSSA isolates result in worse clinical outcomes than infection due to CzIE-negative MSSA isolates? Methods Ovid MEDLINE, Embase, Cochrane CENTRAL, medRxiv and bioRxiv were searched from inception until 12 April 2023. Studies were included if they tested for CzIE in clinical isolates from MSSA infections in humans. Two independent reviewers extracted data and conducted risk-of-bias assessment. Main outcomes were treatment failure and mortality. Pooling of study estimates was not performed given the heterogeneity of patient populations and outcome definitions. Results Twenty-three observational studies were included. CzIE presence amidst MSSA isolates ranged from 0% to 55%. There was no statistically significant mortality difference in two studies that compared MSSA infections with and without CzIE, with ORs ranging from 0.72 to 19.78. Of four studies comparing treatment failure, ORs ranged from 0.26 to 13.00. One study showed a significantly higher treatment failure for the CzIE group, but it did not adjust for potential confounders. Conclusions The evidence on CzIE is limited by small observational studies. In these studies, CzIE did not predict higher mortality in MSSA infections treated with cefazolin. Our findings do not support CzIE testing in clinical practice currently.
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Affiliation(s)
- Calvin Ka-Fung Lo
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Ashwin Sritharan
- Michael G. DeGroote Undergraduate School of Medicine, McMaster University, Hamilton, ON, Canada
| | - Jiesi Zhang
- Faculty of Health Sciences, Queen’s University, Kingston, ON, Canada
| | - Nicole Li
- Faculty of Arts and Sciences, Queen's University, Kingston, ON, Canada
| | - Cindy Zhang
- Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Frank Wang
- Michael G. DeGroote Undergraduate School of Medicine, McMaster University, Hamilton, ON, Canada
| | - Mark Loeb
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Anthony D Bai
- Division of Infectious Diseases, Department of Medicine, Queen’s University, Kingston, ON, Canada
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Haynes AS, Wei Z, Anderson P, Scheetz MH, Parker SK, Fish DN. Cefadroxil and cephalexin pharmacokinetics and pharmacodynamics in children with musculoskeletal infections. Antimicrob Agents Chemother 2024; 68:e0018224. [PMID: 38597672 PMCID: PMC11064491 DOI: 10.1128/aac.00182-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 03/17/2024] [Indexed: 04/11/2024] Open
Abstract
Cephalexin, a first-generation cephalosporin, is the first-line oral therapy for children with musculoskeletal infections due to methicillin-susceptible Staphylococcus aureus (MSSA). Cefadroxil, a similar first-generation cephalosporin, is an attractive alternative to cephalexin given its longer half-life. In this study, we describe the comparative pharmacokinetics (PK) and pharmacodynamics (PD) of cephalexin and cefadroxil in children with musculoskeletal infections. Children aged 6 months to 18 years with a musculoskeletal infection were enrolled in a prospective, open-label, crossover PK study and given single oral doses of cefadroxil (50-75 mg/kg up to 2,000 mg) and cephalexin (50 mg/kg up to 1,375 mg). Population PK models were developed and used for dosing simulations. Our primary PD target was the achievement of free antibiotic concentrations above the minimum inhibitory concentration (fT >MIC) for 40% of the day for MICs ≤ 4 mg/L. PK of cephalexin (n = 15) and cefadroxil (n = 14) were best described using a one-compartment, first-order absorption model, with a lag time component for cefadroxil. PK parameters were notable for cefadroxil's longer half-life (1.61 h) than cephalexin's (1.10 h). For pediatric weight bands, our primary PD target was achieved by cephalexin 25 mg/kg/dose, maximum 750 mg/dose, administered three times daily and cefadroxil 40 mg/kg/dose, maximum 1,500 mg/dose, administered twice daily. More aggressive dosing was required to achieve higher PD targets. Among children with musculoskeletal infections, oral cephalexin and cefadroxil achieved PD targets for efficacy against MSSA. Given less frequent dosing, twice-daily cefadroxil should be further considered as an alternative to cephalexin for oral step-down therapy for serious infections due to MSSA.
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Affiliation(s)
- Andrew S. Haynes
- Children’s Hospital Colorado, Department of Pediatrics, Section of Pediatric Infectious Diseases, Aurora, Colorado, USA
- University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, Colorado, USA
| | - Zixuan Wei
- University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, Colorado, USA
| | - Peter Anderson
- University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, Colorado, USA
| | - Marc H. Scheetz
- Midwestern University, Pharmacometrics Center of Excellence, Colleges of Pharmacy and Pharmacology, Downers Grove, Illinois, USA
| | - Sarah K. Parker
- Children’s Hospital Colorado, Department of Pediatrics, Section of Pediatric Infectious Diseases, Aurora, Colorado, USA
- University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, Colorado, USA
| | - Douglas N. Fish
- University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, Colorado, USA
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3
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Svishchuk J, Ebbert K, Waddell B, Izydorczyk C, Acosta N, Somayaji R, Rabin HR, Bjornson CL, Lisboa L, Gregson DB, Conly JM, Surette MG, Parkins MD. Epidemiology and impact of methicillin-sensitive Staphylococcus aureus with β-lactam antibiotic inoculum effects in adults with cystic fibrosis. Antimicrob Agents Chemother 2023; 67:e0013623. [PMID: 37966229 PMCID: PMC10720481 DOI: 10.1128/aac.00136-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 08/22/2023] [Indexed: 11/16/2023] Open
Abstract
Staphylococcus aureus is the most prevalent cystic fibrosis (CF) pathogen. Several phenotypes are associated with worsened CF clinical outcomes including methicillin-resistance and small-colony-variants. The inoculum effect (IE) is characterized by reduced β-lactam susceptibility when assessed at high inoculum. The IE associates with worse outcomes in bacteremia and other high-density infections, and may therefore be relevant to CF. The prevalence of IE amongst a CF cohort (age ≥18 years), followed from 2013 to 2016, was investigated. Yearly methicillin-sensitive S. aureus (MSSA) isolates were screened at standard (5 × 105 CFU/mL) and high (5 × 107 CFU/mL) inoculum against narrow-spectrum anti-Staphylococcal β-lactams and those with anti-pseudomonal activity common to CF. A ≥ 4-fold increase in minimum inhibitory concentration between standard and high inoculum defined IE. Isolates underwent blaZ sequencing and genotyping and were compared against published genomes. Fifty-six percent (99/177) of individuals had MSSA infection. MSSA was observed at ≥105 CFU/mL in 44.8% of entry sputum samples. The prevalence of the IE was 25.0%-cefazolin; 13.5%-cloxacillin; 0%-meropenem; 1.0%-cefepime; 5.2%-ceftazidime; and 34.4%-piperacillin-tazobactam amongst baseline MSSA isolates assessed. blaZ A associated with cefazolin IE (P = 0.0011), whereas blaZ C associated with piperacillin-tazobactam IE (P < 0.0001). Baseline demographics did not reveal specific risk factors for IE-associated infections, nor were long-term outcomes different. Herein, we observed the IE in CF-derived MSSA disproportionally for cefazolin and piperacillin-tazobactam and this phenotype strongly associated with underlying blaZ genotype. The confirmation of CF being a high density infection, and the identification of high prevalence of MSSA with IE in CF supports the need for prospective pulmonary exacerbation treatment studies to understand the impact of this phenotype.
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Affiliation(s)
- J. Svishchuk
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - K. Ebbert
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - B. Waddell
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - C. Izydorczyk
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - N. Acosta
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - R. Somayaji
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - H. R. Rabin
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - C. L. Bjornson
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - L. Lisboa
- Department of Pathology and Laboratory Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - D. B. Gregson
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
- Department of Pathology and Laboratory Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - J. M. Conly
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
- Department of Pathology and Laboratory Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
| | - M. G. Surette
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - M. D. Parkins
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary and Alberta Health Services, Calgary, Alberta, Canada
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4
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Engstrom EE, Plattner AS, McNeil JC, Hulten KG, Reich PJ, Boyle MG, Dunn JJ, Fritz SA, Kaplan SL. Invasive Community-Onset Gram-Positive Infections From July 2018 Through December 2022 at 2 Children's Hospitals. Open Forum Infect Dis 2023; 10:ofad563. [PMID: 38023538 PMCID: PMC10681712 DOI: 10.1093/ofid/ofad563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/08/2023] [Indexed: 12/01/2023] Open
Abstract
Background Invasive infections caused by Streptococcus pyogenes (invasive group A streptococcus [iGAS]) and Streptococcus pneumoniae (invasive pneumococcal disease [IPD]) decreased substantially at the beginning of the COVID-19 pandemic. Our study sought to evaluate the extent of this decrease and the trends of these infections since reversion of societal adjustments incident to the pandemic. We also wanted to compare the frequency of these infections with invasive community-onset Staphylococcus aureus (I-CO-SA) infections and common respiratory viral infections in this period. Methods Cases of iGAS, IPD, and I-CO-SA infections were identified prospectively and retrospectively at 2 large US children's hospitals by positive cultures from July 2018 through December 2022. Admission data were used to estimate frequency. For comparison, rates of respiratory syncytial virus (RSV), influenza, and SARS-CoV-2 were estimated by the number of positive viral test results at each institution. Results I-CO-SA infections showed little variation in the study period. Rates of iGAS infection and IPD decreased by 46% and 44%, respectively, from 2019 to 2020, coinciding with a substantial decrease in RSV and influenza. In 2022, RSV and influenza infection rates increased to prepandemic winter season rates, coinciding with a return to prepandemic rates of IPD (225% increase from 2021 to 2022) and a surge above prepandemic rates of iGAS infections (543% increase from 2021 to 2022). Conclusions The COVID-19 pandemic had an unexpected influence on IPD and iGAS infections that was temporally related to changes in rates of viral infections.
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Affiliation(s)
- Eric E Engstrom
- Department of Pediatrics, Division of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Alexander S Plattner
- Department of Pediatrics, Division of Infectious Diseases, Washington University in St Louis and St Louis Children's Hospital, St Louis, Missouri, USA
| | - J Chase McNeil
- Department of Pediatrics, Division of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Kristina G Hulten
- Department of Pediatrics, Division of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Patrick J Reich
- Department of Pediatrics, Division of Infectious Diseases, Washington University in St Louis and St Louis Children's Hospital, St Louis, Missouri, USA
| | - Mary G Boyle
- Department of Pediatrics, Division of Infectious Diseases, Washington University in St Louis and St Louis Children's Hospital, St Louis, Missouri, USA
| | - James J Dunn
- Department of Pediatrics, Division of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Stephanie A Fritz
- Department of Pediatrics, Division of Infectious Diseases, Washington University in St Louis and St Louis Children's Hospital, St Louis, Missouri, USA
| | - Sheldon L Kaplan
- Department of Pediatrics, Division of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
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5
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George CRR, Lahra MM, Nguyen T, Gatus B. Disc Test for Detecting Staphylococcus aureus Strains Producing Type A and Type C β-Lactamases. Microbiol Spectr 2023; 11:e0022023. [PMID: 37409947 PMCID: PMC10434206 DOI: 10.1128/spectrum.00220-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 05/22/2023] [Indexed: 07/07/2023] Open
Abstract
Staphylococcus aureus can produce β-lactamases capable of hydrolyzing penicillins and first-generation cephalosporins. The propensity of type A and type C β-lactamase-producing S. aureus (TAPSA and TCPSA) to hydrolyze cefazolin at a high inoculum is termed the cefazolin inoculum effect (CIE). Strains with a CIE have a theoretical risk of causing treatment failure and are unable to be detected routinely by most laboratories. We developed a high-performing yet straightforward β-lactamase disc test that identifies and differentiates both TAPSA and TCPSA and is suitable for routine diagnostic laboratory workflows. Clinical isolates of S. aureus resistant to penicillin were identified, and their blaZ genes were sequenced. MICs were determined at low and high inocula (5 × 105 CFU/mL and 5 × 107 CFU/mL), and isolates demonstrating a CIE were characterized. A semimechanistic model was established to describe differential hydrolysis patterns, and candidate models were iteratively assessed using area-under-the-curve analysis from competitor receiver operating characteristic (ROC) curves. Biomarker thresholds were derived from Youdon index-derived optimal cutoff values. Genetic analysis of 99 isolates identified 26 TAPSA isolates and 45 TCPSA isolates. The model best differentiating TAPSA from non-TAPSA utilized cefazolin-to-cephalothin ratio analysis (sensitivity, 96.2%; specificity, 98.6%). The model best differentiating TCPSA from non-TCPSA incorporated cefazolin, cephalothin, and oxacillin (sensitivity, 88.6%; specificity, 96.6%). TAPSA and TCPSA can be differentiated using three antibiotic discs on a single agar plate. The test has potential value in typing the β-lactamase type from isolates from patients that are candidates for or have failed cefazolin therapy. IMPORTANCE The key significance of this article is that it details a straightforward method of performing a disc test that can differentiate Staphylococcus aureus isolates that are likely to be associated with a cefazolin inoculum effect and theoretical risk of cefazolin treatment failure from isolates that are less likely to be associated with a cefazolin inoculum effect.
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Affiliation(s)
- C. R. Robert George
- NSW Health Pathology, Microbiology, John Hunter Hospital, Newcastle, Australia
| | - Monica M. Lahra
- NSW Health Pathology, Microbiology, Prince of Wales Hospital, Randwick, Australia
- School of Medical Sciences, Faculty of Medicine, the University of New South Wales, Sydney, Australia
| | - Thanh Nguyen
- NSW Health Pathology, Microbiology, Prince of Wales Hospital, Randwick, Australia
| | - Barrie Gatus
- NSW Health Pathology, Microbiology, Prince of Wales Hospital, Randwick, Australia
- School of Medical Sciences, Faculty of Medicine, the University of New South Wales, Sydney, Australia
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6
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Zhao N, Curry D, Evans RE, Isguven S, Freeman T, Eisenbrey JR, Forsberg F, Gilbertie JM, Boorman S, Hilliard R, Dastgheyb SS, Machado P, Stanczak M, Harwood M, Chen AF, Parvizi J, Shapiro IM, Hickok NJ, Schaer TP. Microbubble cavitation restores Staphylococcus aureus antibiotic susceptibility in vitro and in a septic arthritis model. Commun Biol 2023; 6:425. [PMID: 37069337 PMCID: PMC10110534 DOI: 10.1038/s42003-023-04752-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/24/2023] [Indexed: 04/19/2023] Open
Abstract
Treatment failure in joint infections is associated with fibrinous, antibiotic-resistant, floating and tissue-associated Staphylococcus aureus aggregates formed in synovial fluid (SynF). We explore whether antibiotic activity could be increased against Staphylococcus aureus aggregates using ultrasound-triggered microbubble destruction (UTMD), in vitro and in a porcine model of septic arthritis. In vitro, when bacterially laden SynF is diluted, akin to the dilution achieved clinically with lavage and local injection of antibiotics, amikacin and ultrasound application result in increased bacterial metabolism, aggregate permeabilization, and a 4-5 log decrease in colony forming units, independent of microbubble destruction. Without SynF dilution, amikacin + UTMD does not increase antibiotic activity. Importantly, in the porcine model of septic arthritis, no bacteria are recovered from the SynF after treatment with amikacin and UTMD-ultrasound without UTMD is insufficient. Our data suggest that UTMD + antibiotics may serve as an important adjunct for the treatment of septic arthritis.
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Affiliation(s)
- Neil Zhao
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Dylan Curry
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Rachel E Evans
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Selin Isguven
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Theresa Freeman
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
| | - John R Eisenbrey
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Flemming Forsberg
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jessica M Gilbertie
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA
| | - Sophie Boorman
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA
| | - Rachel Hilliard
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA
| | - Sana S Dastgheyb
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Priscilla Machado
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Maria Stanczak
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Marc Harwood
- Rothman Orthopaedic Institute, Philadelphia, PA, USA
| | - Antonia F Chen
- Department of Orthopaedic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Javad Parvizi
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
- Rothman Orthopaedic Institute, Philadelphia, PA, USA
| | - Irving M Shapiro
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Noreen J Hickok
- Department of Orthopaedic Surgery, Sidney Kimmel College, Thomas Jefferson University, Philadelphia, PA, USA.
| | - Thomas P Schaer
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA.
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7
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Staphylococcus aureus Genomic Analysis and Outcomes in Patients with Bone and Joint Infections: A Systematic Review. Int J Mol Sci 2023; 24:ijms24043234. [PMID: 36834650 PMCID: PMC9967247 DOI: 10.3390/ijms24043234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/09/2023] Open
Abstract
Many studies have been published assessing the association between the presence of S. aureus genes and outcomes in patients with bone and joint infections (BJI), but it is not known if they have had similar findings. A systematic literature review was performed. All available data on studies in Pubmed between January 2000 to October 2022 reporting the genetic characteristics of S. aureus and the outcomes of BJIs were analyzed. BJI included prosthetic joint infection (PJI), osteomyelitis (OM), diabetic foot infection (DFI), and septic arthritis. Because of the heterogeneity of studies and outcomes, no meta-analysis was performed. With the search strategy, 34 articles were included: 15 articles on children and 19 articles on adults. In children, most BJI studied were OM (n = 13) and septic arthritis (n = 9). Panton Valentine leucocidin (PVL) genes were associated with higher biological inflammatory markers at presentation (n = 4 studies), more febrile days (n = 3), and more complicated/severe infection (n = 4). Other genes were reported anecdotally associated with poor outcomes. In adults, six studies reported outcomes in patients with PJI, 2 with DFI, 3 with OM, and 3 with various BJI. Several genes were associated with a variety of poor outcomes in adults, but studies found contradictory results. Whereas PVL genes were associated with poor outcomes in children, no specific genes were reported similarly in adults. Additional studies with homogenous BJI and larger sample sizes are needed.
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8
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Going Back in Time: Increasing Penicillin Susceptibility among Methicillin-Susceptible Staphylococcus aureus Osteoarticular Infections in Children. Antimicrob Agents Chemother 2023; 67:e0119622. [PMID: 36598265 PMCID: PMC9872685 DOI: 10.1128/aac.01196-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In the late 1940s to 1950s, Staphylococcus aureus isolates first-gained resistance to penicillin. Recently, some centers have described an increase in the proportion of methicillin susceptible S. aureus (MSSA) which are also susceptible to penicillin (PSSA). There are little data on the frequency of PSSA infections in children. We investigated the prevalence of penicillin susceptibility among pediatric MSSA acute hematogenous osteoarticular infection (OAI) isolates. MSSA OAI isolates were obtained through surveillance studies at Texas Children's and St. Louis Children's Hospitals from January 2011 to December 2019. All isolates underwent PCR for blaZ β-lactamase, PVL genes and agr group. All blaZ negative isolates then underwent penicillin MIC determination. blaZ negative isolates with penicillin MIC ≤ 0.125 μg/mL were considered PSSA. Multilocus sequence typing (MLST) was conducted on a subset of isolates. A total of 329 unique isolates were included in the study. The median patient age was 9.2 years (IQR:5.1 to 12.2). Overall, 6.7% of isolates were penicillin susceptible. No PSSA were detected prior to 2015 but increased yearly thereafter. By the final study year, 20.4% of isolates were PSSA (P = 0.001). PSSA were similar to penicillin-resistant MSSA (PR-MSSA) isolates in terms agr group and PVL carriage as well as clinical presentation and outcomes. PSSA were of distinct sequence types compared to PR-MSSA. PSSA appears to be increasing among OAI in U.S. children. Overall, PSSA isolates are associated with a similar clinical presentation as penicillin-resistant isolates. The potential for use of penicillin treatment in PSSA OAI warrants further study.
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9
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Hitchins M, O'Mara K, Edwards L, Bouchard J. Treatment of persistent methicillin-susceptible Staphylococcus aureus bacteremia and presumed osteomyelitis with oxacillin and ertapenem in a premature neonate. Pharmacotherapy 2023; 43:96-99. [PMID: 36401791 DOI: 10.1002/phar.2745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/02/2022] [Accepted: 11/07/2022] [Indexed: 11/21/2022]
Abstract
Neonatal sepsis remains a high cause of morbidity and mortality in preterm neonates. Methicillin-susceptible Staphylococcus aureus (MSSA) can cause persistent bloodstream infections and invasive disease in neonates. We report the first published case of persistent MSSA bacteremia in a preterm neonate successfully treated with oxacillin and ertapenem combination therapy.
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Affiliation(s)
- Margaret Hitchins
- Department of Pharmacy, WakeMed Health and Hospitals, Raleigh, North Carolina, USA
| | - Keliana O'Mara
- Department of Pharmacy, WakeMed Health and Hospitals, Raleigh, North Carolina, USA
| | - Laura Edwards
- Department of Neonatology, WakeMed Health and Hospitals, Raleigh, North Carolina, USA
| | - Jeannette Bouchard
- Department of Pharmacy, WakeMed Health and Hospitals, Raleigh, North Carolina, USA
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10
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McNeil JC, Sommer LM, Vallejo JG, Hulten KG, Kaplan SL, Flores AR. Reduced Ceftaroline Susceptibility among Invasive MRSA Infections in Children: a Clinical and Genomic Investigation. Antimicrob Agents Chemother 2022; 66:e0074522. [PMID: 36165630 PMCID: PMC9578395 DOI: 10.1128/aac.00745-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 09/05/2022] [Indexed: 11/20/2022] Open
Abstract
Ceftaroline represents an attractive therapy option for methicillin-resistant Staphylococcus aureus (MRSA). Little data is available, however, regarding the frequency of reduced susceptibility (RS) to ceftaroline among pediatric MRSA infections. We screened invasive MRSA isolates at a tertiary children's hospital for ceftaroline RS. Ceftaroline RS occurred in 2.9% of isolates and only among health care associated infections. Ceftaroline RS isolates were more often clindamycin-resistant. Sequencing data indicated the predominance of the CC5 lineage among ceftaroline RS isolates.
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Affiliation(s)
- J. Chase McNeil
- Division of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, Texas, USA
| | - Lauren M. Sommer
- Division of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, Texas, USA
| | - Jesus G. Vallejo
- Division of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, Texas, USA
| | - Kristina G. Hulten
- Division of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, Texas, USA
| | - Sheldon L. Kaplan
- Division of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, Texas, USA
| | - Anthony R. Flores
- Division of Infectious Diseases, Department of Pediatrics, McGovern Medical School, UTHealth Houston, Children’s Memorial Hermann Hospital, Houston, Texas, USA
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11
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Haynes AS, Prinzi A, Silveira LJ, Parker SK, Lampe JN, Kavanaugh JS, Horswill AR, Fish D. Cefadroxil Comparable to Cephalexin: Minimum Inhibitory Concentrations among Methicillin-Susceptible Staphylococcus aureus Isolates from Pediatric Musculoskeletal Infections. Microbiol Spectr 2022; 10:e0103922. [PMID: 35730963 PMCID: PMC9431593 DOI: 10.1128/spectrum.01039-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/25/2022] [Indexed: 11/20/2022] Open
Abstract
Cephalexin and cefadroxil are oral first-generation cephalosporins used to treat methicillin-susceptible Staphylococcus aureus (MSSA) infections. Despite its shorter half-life, cephalexin is more frequently prescribed, although cefadroxil is an appealing alternative, given its slower clearance and possibility for less frequent dosing. We report comparative MIC distributions for cefadroxil and cephalexin, as well as for oxacillin, cephalothin, ceftaroline, and cefazolin, for 48 unique clinical MSSA isolates from pediatric patients with musculoskeletal infections. Both cefadroxil and cephalexin had MIC50 values of 2 μg/mL and MIC90 values of 4 μg/mL. MIC50s for oxacillin, cephalothin, and ceftaroline were ≤0.25 μg/mL, and cefazolin's MIC50 was 0.5 μg/mL. While cefadroxil and cephalexin MICs are higher than those for other active agents, the distributions of MICs for cefadroxil and cephalexin are statistically equivalent, suggesting similar in vitro MSSA activities. Cefadroxil should be further considered an alternative agent to cephalexin, although additional work is needed to identify the optimal dose and frequency of these antibiotics for the treatment of serious MSSA infections. IMPORTANCE Cephalexin and cefadroxil are oral antibiotics that are used to treat serious infections due to the bacteria MSSA. While cephalexin is used more commonly, cefadroxil is excreted from the body more slowly; this generally allows patients to take cefadroxil less frequently than cephalexin. In this study, we compared the abilities of cefadroxil, cephalexin, and several other representative intravenous antibiotics to inhibit the growth of MSSA in the laboratory. Bacterial samples were obtained from children with bone, joint, and/or muscle infections caused by MSSA. We found that cefadroxil and cephalexin inhibited the growth of MSSA at similar concentrations, suggesting similar antibacterial potencies. The selected intravenous antistaphylococcal antibiotics generally inhibited bacterial growth with lower antibiotic concentrations. Based on these results, cefadroxil should be further considered an alternative oral antibiotic to cephalexin, although future research is needed to identify the optimal dose and frequency of these antibiotics for serious infections.
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Affiliation(s)
- Andrew S. Haynes
- Children’s Hospital Colorado, Department of Pediatrics, Section of Pediatric Infectious Diseases, Aurora, Colorado, USA
- University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, Colorado, USA
| | - Andrea Prinzi
- Children’s Hospital Colorado, Department of Pediatrics, Section of Pediatric Infectious Diseases, Aurora, Colorado, USA
- University of Colorado Anschutz Medical Campus, Graduate School, Aurora, Colorado, USA
| | - Lori J. Silveira
- University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, Colorado, USA
| | - Sarah K. Parker
- Children’s Hospital Colorado, Department of Pediatrics, Section of Pediatric Infectious Diseases, Aurora, Colorado, USA
- University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, Colorado, USA
| | - Jed N. Lampe
- University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, Colorado, USA
| | - Jeffrey S. Kavanaugh
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
- Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, Colorado, USA
| | - Douglas Fish
- University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, Colorado, USA
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Prevalence and Characterization of the Cefazolin Inoculum Effect in North American Methicillin-Susceptible Staphylococcus aureus Isolates. J Clin Microbiol 2022; 60:e0249521. [PMID: 35578988 PMCID: PMC9297818 DOI: 10.1128/jcm.02495-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Antistaphylococcal penicillins and cefazolin remain the primary treatments for infections with methicillin-susceptible Staphylococcus aureus (MSSA). The cefazolin inoculum effect (CzIE) causes the cefazolin MIC to be elevated in proportion to the number of bacteria in the inoculum. The objective of this multicenter study was to evaluate the prevalence of the CzIE in North American MSSA isolates. Clinical MSSA isolates from six microbiology laboratories in the United States and one microbiology laboratory in Canada were screened for the CzIE by broth microdilution at a standard inoculum (~5 × 105 CFU/mL) and a high inoculum (~5 × 107 CFU/mL). Genome sequencing was performed to further characterize the MSSA isolates. The CzIE was present in 57/305 (18.6%) MSSA isolates, ranging from 0% to 27.9% across study sites. More of the CzIE-positive isolates (29.8%) had standard inoculum cefazolin MICs of 1.0 μg/mL than the CzIE-negative isolates did (3.2%) (P < 0.0001). Conversely, more CzIE-negative isolates (39.5%) had standard inoculum MICs of 0.25 μg/mL than the CzIE positive isolates did (5.3%) (P < 0.0001). The most common BlaZ β-lactamase types found in the CzIE-positive strains were type C (53.7%) and type A (44.4%). ST8 and ST30 were the most common sequence types among CzIE-positive isolates and correlated with BlaZ type C and A, respectively. The CzIE was present in up to a quarter of clinical MSSA isolates from North American clinical laboratories. Further studies to determine the impact of the presence of the CzIE on clinical outcomes are needed.
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13
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β-Lactam Therapeutic Drug Monitoring in Critically Ill Patients: Weighing the Challenges and Opportunities to Assess Clinical Value. Crit Care Explor 2022; 4:e0726. [PMID: 35815181 PMCID: PMC9259115 DOI: 10.1097/cce.0000000000000726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE: DATA SOURCES: STUDY SELECTION: DATA EXTRACTION: DATA SYNTHESIS: CONCLUSIONS:
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Staphylococcus aureus in Non-Cystic Fibrosis Bronchiectasis: Prevalence and Genomic Basis of High Inoculum Beta-Lactam Resistance. Ann Am Thorac Soc 2022; 19:1285-1293. [PMID: 35213810 DOI: 10.1513/annalsats.202108-965oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rationale The pathobiology of Staphylococcus aureus in non-cystic fibrosis bronchiectasis (nCFB) is poorly defined. When present at high density or "inoculum", some methicillin-sensitive S. aureus (MSSA) can inefficiently degrade anti-Staphylococcal beta-lactam antibiotics via BlaZ penicillinases (termed, the inoculum effect). Given the high burden of organisms in bronchiectatic airways, this is particularly relevant. Objectives Drawing from a prospectively-collected biobank, we sought to understand the prevalence, natural history, potential for transmission, and antibiotic resistance profiles amongst nCFB-derived MSSA isolates. Methods All individuals attending a regional consultancy nCFB clinic with sputum collected between 1981-2017 were considered, and those with ≥1 S. aureus-positive culture comprised the cohort. Each individual's most recent biobank isolate was subjected to whole genome sequencing (including the blaZ gene), antibacterial susceptibility testing, and comparative beta-lactam testing at standard (5 x 105CFU/mL) and high (5 x 107CFU/mL) inoculum to assess for the inoculum, and pronounced inoculum effect (IE and pIE, respectively). Results Seventy-four of 209 (35.4%) individuals had ≥1 sputum sample(s) with S. aureus (68 MSSA, 6 MRSA). Those with S. aureus infection were more likely to be female. Amongst 60/74 MSSA isolates subjected to WGS, no evidence of transmission was identified, although specific MLST types were prevalent including ST-1, ST-15, ST-30, and ST-45. Antibiotic resistance was uncommon except for macrolides (~20%). Amongst the 60 MSSA, prevalence of IE and pIE, respectively, were observed to be drug specific; meropenem (0%, 0%), cefepime (3%, 5%), ceftazidime (8%, 0%), cloxacillin (12%, 0%), cefazolin (23%, 0%) and piperacillin-tazobactam (37%, 17%). The cefazolin IE associated with blaZ type A (p<0.01) and ST-30 (p<0.01), whereas the piperacillin-tazobactam IE associated with type C blaZ (p<0.001) and ST-15 (p<0.05). Conclusions S. aureus infection was common, although no evidence of transmission was apparent in our nCFB cohort. While routine susceptibility testing did not identify significant resistance, inoculum-related resistance was found to be relevant for commonly used nCFB antibiotics including cefazolin and piperacillin-tazobactam. Given previous associations between IEs and negative patient outcomes, further work is warranted to understand how this phenotype impacts nCFB disease progression.
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15
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Diamond S, Vallejo JG, McNeil JC. Microbiology and Treatment Outcomes of Community-Acquired Hematogenous Osteoarticular Infections in Infants ≤12 Months of Age. J Pediatr 2022; 241:242-246.e1. [PMID: 34626668 DOI: 10.1016/j.jpeds.2021.09.057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/20/2021] [Accepted: 09/30/2021] [Indexed: 10/20/2022]
Abstract
We investigated the microbiology, management, and orthopedic outcomes of osteoarticular infections in infants age ≤1 year at our institution. Among 87 patients, Staphylococcus aureus was the most common pathogen (44.8%), followed by group B Streptococcus. Twenty-nine patients (33%), with a median age of 9.2 months, were transitioned to oral antibiotic therapy after ≤14 days of parenteral therapy; orthopedic outcomes were similar to those with prolonged parenteral therapy.
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Affiliation(s)
- Sarah Diamond
- Department of Pediatrics, Section of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, TX
| | - Jesus G Vallejo
- Department of Pediatrics, Section of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, TX
| | - J Chase McNeil
- Department of Pediatrics, Section of Infectious Diseases, Baylor College of Medicine and Texas Children's Hospital, Houston, TX.
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McNeil JC, Joseph M, Sommer LM, Vallejo JG. The Contemporary Epidemiology, Microbiology and Management of Chronic Osteomyelitis in US Children. Pediatr Infect Dis J 2021; 40:518-524. [PMID: 33902075 DOI: 10.1097/inf.0000000000003067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND While the majority of pediatric osteomyelitis cases are acute in nature, a significant subset present with prolonged symptoms often associated with substantial morbidity. Little data exist to guide clinicians in the management of these infections. We sought to describe the epidemiology, clinical features and management of chronic osteomyelitis (CO) in children. METHODS We reviewed hospital admissions for CO from 2011 to 2018 at Texas Children's Hospital. Cases were included if symptoms lasted ≥28 days on presentation. Cases were classified as those associated with: (1) a contiguous focus of infection; (2) penetrating trauma; (3) orthopedic hardware; (4) postacute CO (PACO, those occurring after ≥28 days of therapy for acute osteomyelitis); and (5) primary hematogenous CO. RESULTS One hundred fourteen cases met inclusion criteria. The median patient age was 11.8 years and 35.9% had comorbidities. 70.2% of patients underwent ≥1 surgical procedure. A microbiologic etiology was identified in 72.8% of cases and Staphylococcus aureus was most common (39.4%). Contiguous focus of infection was more often associated with polymicrobial disease with or without Pseudomonas. Postacute CO was caused by S. aureus in 95%. The median duration of total therapy was 210 days. 26.3% of patients experienced treatment failure of which 46% underwent repeat hospital admission/surgery. There was no association between duration of intravenous therapy for CO and treatment failure. CONCLUSIONS Children with CO represent a diverse group both in terms of pathogenesis and microbiology. Pathogenesis and clinical presentation can provide clues to microbiologic etiology. Prolonged intravenous therapy does not appear to improve outcomes in CO.
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Affiliation(s)
- J Chase McNeil
- From the Department of Pediatrics, Section of Infectious Diseases, Baylor College of Medicine, Houston, Texas
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McNeil JC. Acute Hematogenous Osteomyelitis in Children: Clinical Presentation and Management. Infect Drug Resist 2020; 13:4459-4473. [PMID: 33364793 PMCID: PMC7751737 DOI: 10.2147/idr.s257517] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/01/2020] [Indexed: 12/16/2022] Open
Abstract
Acute hematogenous osteomyelitis (AHO) is a common invasive infection encountered in the pediatric population. In addition to the acute illness, AHO has the potential to create long-term morbidity and functional limitations. While a number of pathogens may cause AHO, Staphylococcus aureus is the most common organism identified. Despite the frequency of this illness, little high-quality data exist to guide providers in the care of these patients. The literature is reviewed regarding the epidemiology, microbiology and management of AHO in children. A framework for empiric therapy is provided drawing from the available literature and published guidelines.
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Affiliation(s)
- J Chase McNeil
- Department of Pediatrics, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA
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18
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Almanaa TN, Alyahya SA, Khaled JM, Shehu MR, Alharbi NS, Kadaikunnan S, Alobaidi AS, Khalid Alzahrani A. The extreme drug resistance (XDR) Staphylococcus aureus strains among patients: A retrospective study. Saudi J Biol Sci 2020; 27:1985-1992. [PMID: 32714022 PMCID: PMC7376133 DOI: 10.1016/j.sjbs.2020.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 03/10/2020] [Accepted: 04/02/2020] [Indexed: 12/14/2022] Open
Abstract
The objective of the present work was to observe and profile various antibiotic resistant strains of Staphylococcus aureus and highlight the need for continuous surveillance. Data regarding antibiotic-resistant S. aureus strains isolated and identified at the Medical Microbiology Department, King Khalid Hospital, Riyadh was obtained. Bacterial isolates were collected from several sites of infections in patients and an evaluation of susceptibility were carried out using a fully automated Vitek2 system. Relative frequency (%), odds ratios and Ward's minimum variance were calculated. The results showed that wounds were a source of more than 40% of the S. aureus (MRSA) strains that have ability to resist methicillin, and more than 45% of the methicillin-susceptible S. aureus (non-MRSA) strains. 40% of the isolates were MRSA (N = 251), and all MRSA strains were sensitive to vancomycin, daptomycin, teicoplanin, tigecycline, nitrofurantoin, and itraconazole while all non-MRSA (N = 338) strains were sensitive to vancomycin, cefoxitin, daptomycin, gentamicin, oxacillin, teicoplanin, tigecycline, and mupirocin. Strength of association between antibiotic-resistant S. aureus strains and source of samples (site of infection) was established. The study concluded that S. aureus strains had developed resistance towards 20 (for non-MRSA) and 22 (for MRSA) of the antibiotics tested. All MRSA strains were non-sensitive to amoxicillin/clavulanate, ampicillin cefoxitin, cefazolin, imipenem, oxacillin, and penicillin.
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Affiliation(s)
- Taghreed N Almanaa
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box 4255, Riyadh 11451, Saudi Arabia
| | - Sami A Alyahya
- National Center for Biotechnology, King Abdulaziz City for Science and Technology, Riyadh 11442, Saudi Arabia
| | - Jamal M Khaled
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box 4255, Riyadh 11451, Saudi Arabia
| | - Muhammed R Shehu
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box 4255, Riyadh 11451, Saudi Arabia
| | - Naiyf S Alharbi
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box 4255, Riyadh 11451, Saudi Arabia
| | - Shine Kadaikunnan
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box 4255, Riyadh 11451, Saudi Arabia
| | - Ahmed S Alobaidi
- Department of Botany and Microbiology, College of Science, King Saud University, PO Box 4255, Riyadh 11451, Saudi Arabia
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