Antibiotic susceptibility of Kingella kingae isolates from children with skeletal system infections

Clinical Practice Guideline by the Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA): 2023 Guideline on Diagnosis and Management of Acute Bacterial Arthritis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute bacterial arthritis (ABA) in children was developed by a multidisciplinary panel representing the Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA). This guideline is intended for use by healthcare professionals who care for children with ABA, including specialists in pediatric infectious diseases and orthopedics. The panel's recommendations for the diagnosis and treatment of ABA are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of ABA in children. The panel followed a systematic process used in the development of other IDSA and PIDS clinical practice guidelines, which included a standardized methodology for rating the certainty of the evidence and strength of recommendation using the GRADE approach (Grading of Recommendations Assessment, Development and Evaluation) (see Figure 1). A detailed description of background, methods, evidence summary and rationale that support each recommendation, and knowledge gaps can be found online in the full text.

Impact of guidelines implementation on empiric antibiotic treatment for pediatric uncomplicated osteomyelitis and septic arthritis over a ten-year period: Results of the ELECTRIC study (ostEomyeLitis and sEptiC arThritis tReatment in children)

Background

Due to the growing evidence of the efficacy of intravenous (IV) cefazolin with an early switch to oral cefalexin in uncomplicated pediatric osteomyelitis (OM) and septic arthritis (SA) in children, we changed our guidelines for empiric antibiotic therapy in these conditions. This study aims at evaluating the impact of the guidelines' implementation in reducing broad-spectrum antibiotic prescriptions, duration of IV antibiotic treatment and hospital stay, treatment failure and recurrence.

Materials and methods

This is a retrospective, observational, quasi-experimental study. The four years pre-intervention were compared to the six years, ten months post-intervention (January 2012, through December 2015; January 2016, through October 31st, 2022). All patients aged 3 months to 18 years with OM or SA were evaluated for inclusion. Each population was divided into three groups: pre-intervention, post-intervention not following the guidelines, and post-intervention following the guidelines. Differences in antibiotic prescriptions such as Days of Therapy (DOT), activity spectrum and Length of Therapy (LOT), length of hospital stay (LOS), broad-spectrum antibiotics duration (bsDOT), treatment failure and relapse at six months were analyzed as outcomes.

Results

Of 87 included patients, 48 were diagnosed with OM (8 pre-intervention, 9 post-intervention not following the guidelines and 31 post-intervention following the guidelines) and 39 with SA (9 pre-intervention, 12 post-intervention not following the guidelines and 18 post-intervention following the guidelines). In OM patients, IV DOT, DOT/LOT ratio, and bsDOT were significantly lower in the guidelines group, with also the lowest proportion of patients discharged on IV treatment. Notably, significantly fewer cases required surgery in the post-intervention groups. Considering SA, LOS, IV DOT, DOT/LOT ratio, and bsDOT were significantly lower in the guidelines group. The treatment failure rate was comparable among all groups for both OM and SA. There were no relapse cases. The overall adherence was between 72 and 100%.

Conclusions

The implementation of guidelines was effective in decreasing the extensive use of broad-spectrum antibiotics and combination therapy for both OM and SA. Our results show the applicability, safety, and efficacy of a narrow-spectrum IV empirical antibiotic regimen with cefazolin, followed by oral monotherapy with first/second-generation cephalosporins, which was non-inferior to broad-spectrum regimens.

Distinguishing Kingella kingae from Pyogenic Acute Septic Arthritis in Young Portuguese Children

(1) Background: We aim to identify clinical and laboratorial parameters to distinguish Kingella kingae from pyogenic septic arthritis (SA). (2) Methods: A longitudinal, observational, single-centre study of children < 5 years old with microbiological positive SA admitted to a paediatric hospital from 2013−2020 was performed. Clinical and laboratorial data at admission and at 48 h, as well as on treatment and evolution, were obtained. (3) Results: We found a total of 75 children, 44 with K. kingae and 31 with pyogenic infections (mostly MSSA, S. pneumoniae and S. pyogenes). K. kingae affected younger children with low or absent fever, low inflammatory markers and a favourable prognosis. In the univariate analyses, fever, septic look, CRP and ESR at admission and CRP at 48 h were significantly lower in K. kingae SA. In the multivariate analyses, age > 6 months ≤ 2 years, apyrexy and CRP ≤ 100 mg/L were significative, with an overall predictive positive value of 86.5%, and 88.4% for K. kingae. For this model, ROC curves were capable of differentiating (AUC 0.861, 95% CI 0.767−0.955) K. kingae SA from typical pathogens. (4) Conclusions: Age > 6 months ≤ 2 years, apyrexy and PCR ≤ 100 mg/L were the main predictive factors to distinguish K. kingae from pyogenic SA < 5 years. These data need to be validated in a larger study.

Microbiology of septic arthritis in young Auckland children

BACKGROUND

Kingella kingae is an important cause of septic arthritis in young children, with modern laboratory methods leading to increased detection. Prevalence of this pathogen in New Zealand, where there are high rates of childhood infections due to Staphylococcus aureus and Streptococcus pyogenes, is not known.

METHODS

We conducted a retrospective review of children <5 years with septic arthritis (without osteomyelitis) at a tertiary children's hospital in Auckland, over 10 years (2005-2014). Data were collected on demographics, microbiology, clinical presentation, investigations and management.

RESULTS

Of the 68 cases of septic arthritis, 57 (83.8%) occurred in children aged <24 months. Among those <3 months, Streptococcus agalactiae (Group B streptococcus) was predominant (45.5% of 11 cases), followed by S. aureus (36.4%). The most common pathogen in those 3 to <12 months was Streptococcus pneumoniae (38.5% of 13 cases). In children aged 12 to <24 months, K. kingae was most common (30.3% of 33 cases). Of the 12 cases of K. kingae, 91.7% were identified from synovial fluid culture. All K. kingae isolates were susceptible to amoxicillin.

CONCLUSIONS

K. kingae is the leading pathogen in septic arthritis in New Zealand children aged 12 to <24 months. Routine inoculation of synovial fluid into blood culture bottles at time of sample collection, in addition to use of polymerase chain reaction methods, should be encouraged to improve detection rates. For infants and preschool children presenting with single joint septic arthritis, empiric antibiotics should include cover for S. aureus and K. kingae.

Kingella kingae Spondylodiscitis: Treatment Failure With Flucloxacillin

Kingella kingae infections generally respond well to most beta-lactam antibiotics. We investigated an antibiotic treatment failure in a 3-year-old with K. kingae L3-4 spondylodiscitis. Her disease progressed even after 19 days of high-dose intravenous flucloxacillin. The clinical isolate did not produce a beta-lactamase and despite phenotypic testing and whole-genome sequencing, the mechanism of flucloxacillin resistance remains unknown.

Kingella kingae Osteoarticular Infections Approached through the Prism of the Pediatric Orthopedist

Nowadays, Kingella kingae (K. kingae) is considered as the main bacterial cause of osteoarticular infections (OAI) in children aged less than 48 months. Next to classical acute hematogenous osteomyelitis and septic arthritis, invasive K. kingae infections can also give rise to atypical osteoarticular infections, such as cellulitis, pyomyositis, bursitis, or tendon sheath infections. Clinically, K. kingae OAI are usually characterized by a mild clinical presentation and by a modest biologic inflammatory response to infection. Most of the time, children with skeletal system infections due to K. kingae would not require invasive surgical procedures, except maybe for excluding pyogenic germs' implication. In addition, K. kingae's OAI respond well even to short antibiotics treatments, and, therefore, the management of these infections requires only short hospitalization, and most of the patients can then be treated safely as outpatients.

The role of Kingella kingae in pre-school aged children with bone and joint infections

OBJECTIVES

The Pre-school Osteoarticular Infection (POI) study aimed to describe the burden of disease, epidemiology, microbiology and treatment of acute osteoarticular infections (OAI) and the role of Kingella kingae in these infections.

METHODS

Information about children 3-60 months of age who were hospitalized with an OAI to 11 different hospitals across Australia and New Zealand between January 2012 and December 2016 was collected retrospectively.

RESULTS

A total of 907 cases (73%) were included. Blood cultures grew a likely pathogen in only 18% (140/781). The peak age of presentation was 12 to 24 months (466/907, 51%) and Kingella kingae was the most frequently detected microorganism in this age group (60/466, 13%). In the majority of cases, no microorganism was detected (517/907, 57%). Addition of PCR to culture increased detection rates of K. kingae. However, PCR was performed infrequently (63/907, 7%).

CONCLUSIONS

This large multi-national study highlights the need for more widespread use of molecular diagnostic techniques for accurate microbiological diagnosis of OAI in pre-school aged children. The data from this study supports the hypothesis that a substantial proportion of pre-school aged children with OAI and no organism identified may in fact have undiagnosed K. kingae infection. Improved detection of Kingella cases is likely to reduce the average length of antimicrobial treatment.

Kingella kingae Displaced S. aureus as the Most Common Cause of Acute Septic Arthritis in Children of All Ages

BACKGROUND

Acute septic arthritis (SA) still remains a challenge with significant worldwide morbidity. In recent years, Kingella kingae has emerged and treatment regimens have become shorter. We aim to analyze trends in SA etiology and management and to identify risk factors for complications.

METHODS

Longitudinal observational, single center study of children (<18 years old) with SA admitted to a tertiary care pediatric hospital, from 2003 to 2018, in 2 cohorts, before and after implementation of nucleic acid amplification assays (2014). Clinical, treatment and disease progression data were obtained.

RESULTS

A total of 247 children were identified, with an average annual incidence of 24.9/100,000, 57.9% males with a median age of 2 (1-6) years. In the last 5 years, a 1.7-fold increase in the annual incidence, a lower median age at diagnosis and an improved microbiologic yield (49%) was noticed. K. kingae became the most frequent bacteria (51.9%) followed by MSSA (19.2%) and S. pyogenes (9.6%). Children were more often treated for fewer intravenous days (10.7 vs. 13.2 days, P = 0.01) but had more complications (20.6% vs. 11.4%, P = 0.049) with a similar sequelae rate (3.7%). Risk factors for complications were C-reactive protein ≥80 mg/L and Staphylococcus aureus infection, and for sequelae at 6 months, age ≥4 years and CRP ≥ 80 mg/L.

CONCLUSIONS

The present study confirms that K. kingae was the most common causative organism of acute SA. There was a trend, although small, for decreasing antibiotic duration. Older children with high inflammatory parameters might be at higher risk of sequelae.

Acute Hematogenous Osteomyelitis in Children: Clinical Presentation and Management

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.

The first report on epidemiology of oropharyngeal Kingella kingae carriage in Scandinavian children: K. kingae carriage is very common in children attending day care facilities in Western Norway

Kingella kingae colonizes the upper airways in children and has been recognized as the most common causative agent of osteoarticular infections (OAI) in children below 4 years of age. This is the first Scandinavian study to investigate oropharyngeal K. kingae carriage in healthy children. From June 2015 to August 2016, we recruited 198 healthy children aged 11-14 months from routine consultations at health promotion centers in Hordaland County, Norway for a cross-sectional study. After their parents had provided informed consent; demographic data were registered, and an oropharyngeal swab was collected. The oropharyngeal swab was analyzed with a real-time PCR assay specific to K. kingae targeting the RTX toxin locus. Results showed an asymptomatic carriage rate of 12.6%. A striking and highly significant difference was observed between the children that had started attending day care facilities as compared with children still being at home (33.33% vs 8.5%; p < 0.001). K. kingae is prevalent in young children in Norway. This study emphasize that K. kingae should be considered an important etiological agent in OAI. Transmission seems to be facilitated in day care facilities. The correlation between oropharyngeal carriage and OAI needs to be further explored.

Clinical Features and Outcomes of Children with Culture-Negative Septic Arthritis

BACKGROUND

Septic arthritis is a serious infection, but the results of blood and joint fluid cultures are often negative in children. We describe here the clinical features and management of culture-negative septic arthritis in children at our hospital and their outcomes.

METHODS

We performed a retrospective review of a cohort of children with septic arthritis who were hospitalized at Children's Hospital of Philadelphia between January 2002 and December 2014. Culture-negative septic arthritis was defined as a joint white blood cell count of >50000/μL with associated symptoms, a clinical diagnosis of septic arthritis, and a negative culture result. Children with pretreatment, an intensive case unit admission, Lyme arthritis, immunodeficiency, or surgical hardware were excluded. Treatment failure included a change in antibiotics, surgery, and/or reevaluation because of a lack of improvement/worsening.

RESULTS

We identified 157 children with septic arthritis. The patients with concurrent osteomyelitis (n = 28) had higher inflammatory marker levels at presentation, had a longer duration of symptoms (median, 4.5 vs 3 days, respectively; P < .001), and more often had bacteremia (46.4% vs 6.2%, respectively; P < .001). Among children with septic arthritis without associated osteomyelitis, 69% (89 of 129) had negative culture results. These children had lower C-reactive protein levels (median, 4.0 vs 7.3 mg/dL, respectively; P = .001) and erythrocyte sedimentation rates (median, 39 vs 51 mm/hour, respectively; P = .01) at admission and less often had foot/ankle involvement (P = .02). Among the children with culture-negative septic arthritis, the inpatient treatment failure rate was 9.1%, and treatment failure was more common in boys than in girls (17.1% vs 3.8%, respectively; P = .03). We found no association between treatment failure and empiric antibiotics or patient age. No outpatient treatment failures occurred during the 6-month follow-up period, although 17% of the children discharged with a peripherally inserted central catheter line experienced complications, including 3 with bacteremia.

CONCLUSIONS

The majority of septic arthritis infections at our institution were culture negative. Among patients with culture-negative infection, empiric antibiotics failed for 9% and necessitated a change in therapy. More sensitive diagnostic testing should be implemented to elucidate the causes of culture-negative septic arthritis in children.

Diagnosis and Management of Infectious Arthritis in Children

PURPOSE OF REVIEW

Septic arthritis is limb and life-threatening condition which necessitates rapid diagnosis and treatment. It is important for a medical practitioner to be familiar with this condition. This review summarizes the epidemiology, risk factors, diagnosis and differential diagnosis, complications, as well as treatment and the following-up of this condition.

RECENT FINDINGS

Different causative organisms require unique diagnostic and treatment approaches. Establishing the diagnosis often requires multiple diagnostic modalities, some of which are new and innovative. Differential diagnosis requires excluding non-infectious inflammatory causes, such as reactive arthritis, juvenile rheumatoid arthritis, transient synovitis, and pericapsular pyomyositis. There is no consensus regarding the nature or duration of pharmacological or surgical treatment. Treatment includes administration of appropriate antimicrobial therapy and including the use of steroids and drainage. The most common complications are osteonecrosis of the femoral head and chronic osteomyelitis. Complications of septic arthritis are mostly due to a missed diagnosis. Further studies are required to better evaluate the diagnostic and therapeutic choice.

Bacteriological profile of community-acquired musculoskeletal infections: a study from Queensland

BACKGROUND

The purpose of this study was to determine bacteriology of community-acquired musculoskeletal infections requiring hospitalization and to compare this with published national and international data. This will help treating physicians select the appropriate antibiotic.

METHODS

All patients who underwent surgical procedures for community-acquired musculoskeletal infections over a period of 22 months were included in the study. Hospital acquired infections, post-operative infections and infections involving prosthetic joints were excluded. Patient characteristics, treatment details, cultured organisms and their antibiotic sensitivity were recorded.

RESULTS

Forty-five patients with 46 cases met the inclusion criteria. Ten patients were from paediatric age group. Soft tissue infections were the most common diagnosis and accounted for 20 cases. The remainder were septic arthritis (n = 17) and osteomyelitis (n = 9). Thirteen patients (28.3%) had negative cultures from the operative samples. Staphylococcus aureus was the most common isolated organism overall accounting for 23 cases (69.7%). Methicillin-resistant S. aureus (MRSA) sensitive to vancomycin was cultured in four adult cases (12.1%), of which three were hand infections (50%). For the entire cohort, 67.7% and 61.3% isolates that were tested were sensitive to cefazolin and flucloxacillin, respectively.

CONCLUSION

The bacteriological profile in this study is consistent with European and Australian data. While the overall MRSA infection rate was low, it was much higher among hand infections and is comparable to reports from the USA. Flucloxacillin and cefazolin should be considered as the first line of antibiotic therapy for all cases. Vancomycin should be considered when MRSA is suspected.

Polymerase chain reaction detection of Kingella kingae in children with culture-negative septic arthritis in eastern Ontario

BACKGROUND

The bacterium Kingella kingae may be an under-recognized cause of septic arthritis in Canadian children because it is difficult to grow in culture and best detected using molecular methods.

OBJECTIVES

To determine whether K kingae is present in culture-negative joint fluid specimens from children in eastern Ontario using polymerase chain reaction (PCR) detection methods.

METHODS

K kingae PCR testing was performed using residual bacterial culture-negative joint fluid collected from 2010 to 2013 at a children's hospital in Ottawa, Ontario. The clinical features of children with infections caused by K kingae were compared with those of children with infections caused by the 'typical' septic arthritis bacteria, Staphylococcus aureus and Streptococcus pyogenes.

RESULTS

A total of 50 joint fluid specimens were submitted over the study period. Ten were culture-positive, eight for S aureus and two for S pyogenes. Residual joint fluid was available for 27 of the 40 culture-negative specimens and K kingae was detected using PCR in seven (25.93%) of these samples. Children with K kingae were significantly younger (median age 1.7 versus 11.3 years; P=0.01) and had lower C-reactive protein levels (median 23.8 mg/L versus 117.6. mg/L; P=0.01) than those infected with other bacteria.

CONCLUSIONS

K kingae was frequently detected using PCR in culture-negative joint fluid specimens from children in eastern Ontario. K kingae PCR testing of culture-negative joint samples in children appears to be warranted.

Kingella kingae: carriage, transmission, and disease

Kingella kingae is a common etiology of pediatric bacteremia and the leading agent of osteomyelitis and septic arthritis in children aged 6 to 36 months. This Gram-negative bacterium is carried asymptomatically in the oropharynx and disseminates by close interpersonal contact. The colonized epithelium is the source of bloodstream invasion and dissemination to distant sites, and certain clones show significant association with bacteremia, osteoarthritis, or endocarditis. Kingella kingae produces an RTX (repeat-in-toxin) toxin with broad-spectrum cytotoxicity that probably facilitates mucosal colonization and persistence of the organism in the bloodstream and deep body tissues. With the exception of patients with endocardial involvement, children with K. kingae diseases often show only mild symptoms and signs, necessitating clinical acumen. The isolation of K. kingae on routine solid media is suboptimal, and detection of the bacterium is significantly improved by inoculating exudates into blood culture bottles and the use of PCR-based assays. The organism is generally susceptible to antibiotics that are administered to young patients with joint and bone infections. β-Lactamase production is clonal, and the local prevalence of β-lactamase-producing strains is variable. If adequately and promptly treated, invasive K. kingae infections with no endocardial involvement usually run a benign clinical course.

[SEIP-SERPE-SEOP Consensus document on the treatment of uncomplicated acute osteomyelitis and septic arthritis]

This is a Consensus Document of the Spanish Society of Paediatric Infectious Diseases (Sociedad Española de Infectología Pediatrica), Spanish Society of Paediatric Rheumatology (Sociedad Española de Reumatología Pediátrica) and the Spanish Society of Paediatric Orthopaedics (Sociedad Española de Ortopedia Pediátrica), on the treatment of uncomplicated acute osteomyelitis and septic arthritis. A review is presented on the medical and surgical treatment of acute osteoarticular infection, defined as a process with less than 14 days of symptomatology, uncomplicated and community-acquired. The different possible options are evaluated based on the best available scientific knowledge, and a number of evidence-based recommendations for clinical practice are provided.

First identification of a chromosomally located penicillinase gene in Kingella kingae species isolated in continental Europe

Kingella kingae is the major pathogen causing osteoarticular infections (OAI) in young children in numerous countries. Plasmid-borne TEM-1 penicillinase production has been sporadically detected in a few countries but not in continental Europe, despite a high prevalence of K. kingae infections. We describe here for the first time a K. kingae β-lactamase-producing strain in continental Europe and demonstrate the novel chromosomal location of the blaTEM-1 gene in K. kingae species.

Genotyping, local prevalence and international dissemination of β-lactamase-producing Kingella kingae strains

β-lactamase production has been sporadically reported in the emerging Kingella kingae pathogen but the phenomenon has not been studied in-depth. We investigated the prevalence of β-lactamase production among K. kingae isolates from different geographical origins and genetically characterized β-lactamase-producing strains. Seven hundred and seventy-eight isolates from Iceland, the USA, France, Israel, Spain and Canada were screened for β-lactamase production and, if positive, were characterized by PFGE and MLST genotyping, as well as rtxA, por, blaTEM and 16S rRNA sequencing. β-lactamase was identified in invasive strains from Iceland (n=4/14, 28.6%), the USA (n=3/15, 20.0%) and Israel (n=2/190, 1.1%) and in carriage strains in the USA (n=5/17, 29.4%) and Israel (n=66/429, 15.4%). No French, Spanish or Canadian isolates were β-lactamase producers. Among β-lactamase producers, a perfect congruency between the different typing methods was observed. Surprisingly, all US and Icelandic β-lactamase-producing isolates were almost indistinguishable, belonged to the major international invasive PFGE clone K/MLST ST-6, but differed from the four genetically unrelated Israeli β-lactamase-producing clones. Representative strains of different genotypes produced the TEM-1 enzyme. K. kingae β-lactamase producers exhibit a clear clonal distribution and have dissimilar invasive potential. The presence of the enzyme in isolates belonging to the major worldwide invasive clone K/ST-6 highlights the possible spread of β-lactam resistance, and emphasizes the importance of routine testing of all K. kingae clinical isolates for β-lactamase production.

Characterization of TEM-1 β-Lactamase-Producing Kingella kingae Clinical Isolates

Kingella kingae is a human pathogen that causes pediatric osteoarticular infections and infective endocarditis in children and adults. The bacterium is usually susceptible to β-lactam antibiotics, although β-lactam resistance has been reported in rare isolates. This study was conducted to identify β-lactam-resistant strains and to characterize the resistance mechanism. Screening of a set of 90 K. kingae clinical isolates obtained from different geographic locations revealed high-level resistance to penicillins among 25% of the strains isolated from Minnesota and Iceland. These strains produced TEM-1 β-lactamase and were shown to contain additional ≥50-kb plasmids. Ion Torrent sequencing of extrachromosomal DNA from a β-lactamase-producing strain confirmed the plasmid location of the bla_TEM gene. An identical plasmid pattern was demonstrated by multiplex PCR in all β-lactamase producers. The porin gene's fragments were analyzed to investigate the relatedness of bacterial strains. Phylogenetic analysis revealed 27 single-nucleotide polymorphisms (SNPs) in the por gene fragment, resulting in two major clusters with 11 allele types forming bacterial-strain subclusters. β-Lactamase producers were grouped together based on por genotyping. Our results suggest that the β-lactamase-producing strains likely originate from a single plasmid-bearing K. kingae isolate that traveled from Europe to the United States, or vice versa. This study highlights the prevalence of penicillin resistance among K. kingae strains in some regions and emphasizes the importance of surveillance for antibiotic resistance of the pathogen.

30 years of study of Kingella kingae: post tenebras, lux

Kingella kingae is a Gram-negative bacterium that is today recognized as the major cause of joint and bone infections in young children. This microorganism is a member of the normal flora of the oropharynx, and the carriage rate among children under 4 years of age is approximately 10%. K. kingae is transmitted from child to child through close personal contact. Key virulence factors of K. kingae include expression of type IV pili, Knh-mediated adhesive activity and production of a potent RTX toxin. The clinical presentation of K. kingae invasive infection is often subtle and may be associated to mild-to-moderate biologic inflammatory responses, highlighting the importance a high index of suspicion. Molecular diagnosis of K. kingae infections by nucleic acid amplification techniques enables identification of this fastidious microorganism. Invasive infections typically respond favorably to medical treatment, with the exception of cases of endocarditis, which may require urgent valve replacement.