Associations Between Findings of Fusobacterium necrophorum or β-Hemolytic Streptococci and Complications in Pharyngotonsillitis-A Registry-Based Study in Southern Sweden

BACKGROUND

Most pharyngotonsillitis guidelines focus on the identification of group A streptococci (GAS), guided by clinical scores determining whom to test with a rapid antigen detection test. Nevertheless, many patients testing negative with this test are evaluated for group C/G streptococci (GCS/GGS) and Fusobacterium necrophorum, yet their importance remains debated. Our primary aim was to evaluate associations between complications and findings of F. necrophorum, GAS, or GCS/GGS in pharyngotonsillitis.

METHODS

This was a retrospective, registry-based study of pharyngotonsillitis cases tested for F. necrophorum (polymerase chain reaction) and β-hemolytic streptococci (culture) in the Skåne Region, Sweden, in 2013-2020. Patients with prior complications or antibiotics (within 30 days) were excluded. Data were retrieved from registries and electronic charts. Logistic regression analyses were performed with a dichotomous composite outcome of complications as primary outcome, based on International Classification of Diseases, Tenth Revision, codes. Cases with negative results (polymerase chain reaction and culture) were set as reference category. Complications within 30 days were defined as peritonsillar or pharyngeal abscess, otitis, sinusitis, sepsis or septic complications, recurrence of pharyngotonsillitis (after 15-30 days) or hospitalization.

RESULTS

Of 3700 registered cases, 28% had F. necrophorum, 13% had GCS/GGS, 10% had GAS, and 54% had negative results. The 30-day complication rates were high (20%). F. necrophorum (odds ratio, 1.8; 95% confidence interval, 1.5-2.1) and GAS (1.9; 1.5-2.5) were positively associated with complications, whereas GCS/GGS were negatively associated (0.7; 0.4-0.98).

CONCLUSIONS

Our results indicate that F. necrophorum is a relevant pathogen in pharyngotonsillitis, whereas the relevance of testing for GCS/GGS is questioned. However, which patient to test and treat for F. necrophorum remains to be defined.

A genome-led study on the pathogenesis of Fusobacterium necrophorum infections

Fusobacterium necrophorum causes a range of mild to life threatening infections and there is uncertainty in terms of diagnosis and treatment due to the lack of knowledge on their pathogenic mechanisms. This study characterised genomes of F. necrophorum to compare their virulence factors and investigate potential infection markers. 27 isolates of F. necrophorum from patients with pharyngotonsillitis were subjected to whole genome sequencing and compared with 42 genomes published in the NCBI database. Phylogenomics, pangemome, pan-GWAS and virulome were analysed to study strain variations with reference to virulence factors. Core genome based phylogenomic tree exhibited three clades of which Clade A belonged to F. necrophorum subsp necrophorum, clades B and C were F. necrophorum subsp funduliforme. Pan-GWAS and Pan-Virulome suggest some marker genes associated with clinical sources of isolation that needs further validation. Our study highlights some interesting features of the pathogenesis of F. necrophorum infections. Although the animal isolate genomes had some marker genes, the genomes of human isolates did not exhibit clear correlation to their clinical sources of isolation. This prompts to think of other mechanisms such as co-infections or host factors that can be involved in the pathogenesis.

In Vivo Secretion of β-Lactamase-Carrying Outer Membrane Vesicles as a Mechanism of β-Lactam Therapy Failure

Outer membrane vesicles carrying β-lactamase (βLOMVs) protect bacteria against β-lactam antibiotics under experimental conditions, but their protective role during a patient’s treatment leading to the therapy failure is unknown. We investigated the role of βLOMVs in amoxicillin therapy failure in a patient with group A Streptococcus pyogenes (GAS) pharyngotonsillitis. The patient’s throat culture was examined by standard microbiological procedures. Bacterial vesicles were analyzed for β-lactamase by immunoblot and the nitrocefin assay, and in vivo secretion of βLOMVs was detected by electron microscopy. These analyses demonstrated that the patient’s throat culture grew, besides amoxicillin-susceptible GAS, an amoxicillin-resistant nontypeable Haemophilus influenzae (NTHi), which secreted βLOMVs. Secretion and β-lactamase activity of NTHi βLOMVs were induced by amoxicillin concentrations reached in the tonsils during therapy. The presence of NTHi βLOMVs significantly increased the minimal inhibitory concentration of amoxicillin for GAS and thereby protected GAS against bactericidal concentrations of amoxicillin. NTHi βLOMVs were identified in the patient’s pharyngotonsillar swabs and saliva, demonstrating their secretion in vivo at the site of infection. We conclude that the pathogen protection via βLOMVs secreted by the flora colonizing the infection site represents a yet underestimated mechanism of β-lactam therapy failure that warrants attention in clinical studies.

Probiotics in the add-on treatment of pharyngotonsillitis: a clinical experience

Pharyngotonsillitis is a common disease, mainly characterized by a sore throat. It may be classified as acute or chronic, based on duration. The diagnosis is usually performed on the clinical ground, and antibiotic therapy is frequently used in clinical practice. However, antibiotics frequently induce intestinal dysbiosis associated with some clinical problems. Therefore, probiotics are commonly prescribed in patients treated with antibiotics. The current clinical experience was conducted in patients with pharyngotonsillitis and treated with antibiotics. A one-month course of a probiotic mixture (Abincol® containing Lactobacillus plantarum LP01 (1 billion of living cells), Lactobacillus lactis subspecies cremoris LLC02 (800 million of living cells), and Lactobacillus delbrueckii subspecies delbrueckii LDD01 (200 million of living cells), was prescribed in the Group A, and was compared with no add-on treatment, such as the Group B. Patients were evaluated at baseline (T0), at the end of antibiotic treatment (T1), at the end of probiotic course (T2), and at the end of 3-month follow-up (T3). Globally, 1118 outpatients were enrolled. Acute pharyngotonsillitis affected 795 subjects: 396 in Group A and 399 in Group B. Chronic pharyngotonsillitis affected 323 outpatients: 158 in Group A and 165 in Group B. All patients were usually treated with a 7-10-day course of antibiotic therapy. In patients with acute pharyngotonsillitis, the probiotic mixture significantly reduced the duration of all the symptoms (p<0.001 for all), except for the urinary tract infection, associated with antibiotic therapy which was already at the end of the antibiotic cycle (T1). The intergroup analysis showed that patients with chronic pharyngotonsillitis in Group A had significantly less tiredness, pain, and malaise (p<0.001 for all) than patients in Group B at T1. The probiotic course reduced the possible clinical relapse, and the use of additional medications at T2 and T3 in patients with both acute and chronic pharyngotonsillitis. In conclusion, the present clinical experience demonstrated that a probiotic mixture containing Lactobacillus plantarum LP01, Lactobacillus lactis subspecies cremoris LLC02, and Lactobacillus delbrueckii, was able to quickly reduce symptoms, possible relapse, and use of additional medications, associated with antibiotic therapy, in patients with both acute and chronic pharyngotonsillitis.

Probiotics in the add-on treatment of laryngotracheitis: a clinical experience

Laryngotracheitis is a common disease, mainly characterized by dysphonia, cough, and sore throat. The diagnosis is usually based on the clinical ground, and antibiotic therapy is frequently used in clinical practice. However, antibiotics frequently induce intestinal dysbiosis associated with some clinical problems. The current clinical experience was conducted in patients with pharyngotonsillitis and treated with antibiotics. A one-month course of a probiotic mixture (Abincol® containing Lactobacillus plantarum LP01 (1 billion of living cells), Lactobacillus lactis subspecies cremoris LLC02 (800 million living cells), and Lactobacillus delbrueckii LDD01 (200 million living cells), was prescribed in the Group A, and was compared with no add-on treatment, such as the Group B. Patients were evaluated at baseline (T0), at the end of antibiotic treatment (T1), at the end of probiotic course (T2), and at the end of 3-month follow-up (T3). Globally, 833 outpatients with laryngotracheitis were enrolled: 425 in Group A and 408 in Group B. All of them were treated with a 7-10-day course of antibiotic therapy. The probiotic mixture reduced the duration of symptoms associated with antibiotic therapy already at the end of the antibiotic cycle. The intergroup comparison showed that probiotic group patients experienced less fever, tiredness, headache, pain, malaise, diarrhea, and nausea (p<0.001 for all) than control patients at T1. The probiotic course reduced the possible clinical relapse, and the use of additional medications at T2 and T3. In conclusion, the present clinical experience demonstrated that a probiotic mixture containing Lactobacillus plantarum LP01, Lactobacillus lactis subspecies cremoris LLC02, and Lactobacillus delbrueckii subspecies delbrueckii, was able to rapidly reduce symptoms associated with antibiotic therapy in patients with laryngotracheitis.

Changes in epidemiologic characteristics and antimicrobial resistance of Streptococcus pyogenes isolated over 10 years from Japanese children with pharyngotonsillitis

Introduction. Pharyngotonsillitis caused by Streptococcus pyogenes (group A streptococci, or GAS) is among the most common infections treated with antibiotics in pediatric patients.Aim. This study aimed to analyse changes in molecular epidemiology and antibiotic susceptibility among GAS isolates in three study periods spanning 10 years.Methodology. GAS isolated from paediatric patients with pharyngotonsillitis during Period I (mid-2007 to 2008, n=235), Period II (2012, n=210), and Period III (2018, n=189) were analysed for emm type, multilocus sequence type (MLST), antibiotic susceptibility, and macrolide (ML)- and quinolone (QL)-resistance genes.Results. Over 20 % of isolates represented emm1 and emm12 types, remaining common in all three periods. Among other emm types, emm4 was common in Period I, emm28 and emm89 in Period II, and emm3 and emm89 in Period III. All isolates remained highly susceptible to penicillins and cephalosporins. Isolates possessing mefA, ermA, or ermB genes mediating ML resistance increased from 34.9 % in Period I to 60.9 % in Period II, but fell to 27.5 % in Period III. QL-resistant isolates with amino acid substitutions affecting ParC and/or GyrA gradually increased from 11.5 to 14.3 %. Specific sequence types identified by MLST and emm typing were associated closely with ML or QL resistance.Conclusion. Our findings indicate that even in ambulatory care, antibiotic choice for these infections should be based on rapid identification and characterization of causative pathogens.

Carditis in Acute Rheumatic Fever in a High-Income and Moderate-Risk Country

OBJECTIVE

To describe clinical presentation, electrocardiographic, and echocardiographic characteristics of carditis at the time of diagnosis of acute rheumatic fever (ARF) over a 13-year period.

STUDY DESIGN

A single-center retrospective chart analysis was conducted involving all consecutive patients diagnosed with ARF between 2003 and 2015. Patient age, sex, clinical characteristics, recent medical history for group A streptococcal pharyngotonsillitis and antibiotic treatment, and laboratory, echocardiographic, and electrocardiographic findings were recorded.

RESULTS

Of 98 patients (62 boys, mean age 8.81 ± 3.04 years), 59 (60.2%) reported a positive history of pharyngotonsillitis; 48 (49%) had received antibiotic (mean duration of treatment of 5.9 ± 3.1 days), and, among these, 28 (58.3%) had carditis. Carditis was the second most frequent finding, subclinical in 27% of patients. Mitral regurgitation was present in 49 of 56 patients (87.5%) and aortic regurgitation in 36/56 (64.3%) no stenosis was documented.

CONCLUSIONS

ARF is still present in high-income countries and can develop despite primary prophylaxis, especially when given for a short course. Our findings highlight the need for 10 days of antistreptococcal treatment to prevent ARF. Echocardiography is important because 27% of cases with carditis were subclinical.

Potential for Molecular Testing for Group A Streptococcus to Improve Diagnosis and Management in a High-Risk Population: A Prospective Study

Background

In high-burden settings, guidelines recommend antibiotic treatment for all suspected group A Streptococcus (GAS) infections to prevent rheumatic fever and poststreptococcal glomerulonephritis. Highly sensitive rapid GAS tests could reduce unnecessary antibiotic use in these settings.

Methods

This was a prospective study of the Xpert Xpress Strep A (Cepheid) molecular test compared with culture of throat swab samples collected at a referral hospital in northern Australia. Demographic and clinical data and results of streptococcal serology and culture were collected.

Results

Of 164 throat swab samples, 145 (88%) were eligible for inclusion; 49 (34%) were molecular test positive and 24 (17%) were culture positive for GAS. The sensitivity, specificity, and positive and negative predictive values for the molecular test versus culture were 100.0%, 79.3%, 48.8%, and 100.0%, respectively. Among 25 samples testing positive with the molecular test and negative with culture, group C or G streptococci were cultured in 2, and a plausible clinical explanation, such as pharyngotonsillitis, or rheumatic fever with positive results of streptococcal serology, was apparent in 19 instances. In 25 patients with rheumatic fever or poststreptococcal glomerulonephritis diagnoses, molecular testing nearly trebled the detection of GAS in throat swab samples, from 3 (12%) detected with culture to 8 (32%) detected with molecular testing. Reasons for “false-positive” molecular test results could include the presence of GAS below the threshold of culture detection or persistence of nonviable organisms after infection.

Conclusion

Implementation of molecular testing could improve antibiotic use in this high-burden setting. The incremental yield in poststreptococcal syndromes, by which time cultures are negative, has high potential in the diagnostic workup of autoimmune poststreptococcal syndromes and warrants further investigation.

Fusobacterium necrophorum Subsp. funduliforme in Tonsils from Various Patient Populations in Japan

Fusobacterium necrophorum has recently been suggested to be associated with tonsillopharyngitis, peritonsillar abscess, and recurrent tonsillitis. Between the 2 subspecies of F. necrophorum, subsp. funduliforme is known to be a major human pathogen. To better understand the epidemiology of F. necrophorum subsp. funduliforme (FNSF), we studied the prevalence of FNSF in the tonsils of patients undergoing elective tonsillectomy (TE) for different indications. Adult patients who underwent elective TE from October 2014 to November 2015 were included. The tonsils were sent for aerobic and anaerobic tissue culture within 30 min of excision; the presence of FNSF was detected using PCR with gyrB primers and 16S rRNA. A total of 32 patients were enrolled. The prevalence of FNSF identified by either culture or gyrB PCR did not significantly differ between infectious and noninfectious TE indications. The constant presence of FNSF might not be associated with recurrent pharyngotonsillitis.

Positive clinical outcomes derived from using Streptococcus salivarius K12 to prevent streptococcal pharyngotonsillitis in children: a pilot investigation

Background

Streptococcus salivarius K12 (BLIS K12^®) is a probiotic strain producing the bacteriocins salivaricin A2 and salivaricin B, both of which strongly antagonize the growth of Streptococcus pyogenes, the most important bacterial cause of pharyngeal infections in humans. It successfully colonizes and exhibits persistence in the oral cavity and is endowed with an excellent safety profile. Previous observations of a small group of children indicated that the use of BLIS K12 could also reduce the occurrence of viral pharyngitis. The present study focused on a further evaluation of the role of BLIS K12 in the control of pediatric streptococcal disease and moreover whether its use could also help provide protection against various nonstreptococcal infections.

Methods

In total, 48 children with a recent history of recurrent pharyngeal streptococcal disease were enrolled in the treated group. The control group comprised 76 children known to have had a very low recent occurrence of oral streptococcal disease. The treated children were given BLIS K12 daily for 90 days. The number of episodes of streptococcal pharyngotonsillitis, tracheitis, viral pharyngitis, rhinitis, flu, laryngitis, acute otitis media, enteritis, and stomatitis was recorded during probiotic treatment and for a follow-up period of 9 months, and this was compared with the episodes of the control group over the corresponding period.

Results

Compared with the pretreatment time period, 2013, a 90% reduction of streptococcal pharyngeal disease was observed in 2014; compared with untreated children, a statistically significant reduction of all of the other disease conditions assessed, other than stomatitis, was detected in the probiotic-treated children.

Conclusion

In agreement with previous findings, in the present study, it was found that the daily use of BLIS K12 has been associated with a concurrent and persisting reduction in the occurrence of pharyngeal, recurrent, streptococcal disease. Moreover, the benefits to children may also extend to a reduction of nonstreptococcal diseases, including tracheitis, viral pharyngitis, rhinitis, flu, laryngitis, acute otitis media, and enteritis.

Vitamin D and respiratory tract infections in childhood

BACKGROUND

Respiratory tract infections (RTIs) remain among of the most important causes of morbidity and mortality among children. Several studies have associated vitamin D deficiency with an increased risk of RTIs, and vitamin D supplementation has been proposed as a possible preventive measure against RTIs in children. The main aim of this review is to summarize the current evidence from the literature about the link between vitamin D and RTIs in children.

DISCUSSION

Several recent studies have shown that vitamin D has different immunomodulatory properties associated with the risk of RTIs in childhood. In this regard, it is very important to understand the definition of deficiency and insufficiency of vitamin D and when and how to treat this condition. Unfortunately, there is no consensus, although a level of at least 10 ng/mL 25-hydroxycholecalciferol (25[OH]D) is thought to be necessary to promote bone mineralization and calcium homeostasis, and a concentration between 20 ng/mL and 50 ng/mL is considered adequate to provide an immunomodulatory effect. Available data support a role for vitamin D deficiency in the risk of pediatric tuberculosis, recurrent acute otitis media, and severe bronchiolitis, whereas further studies are needed to confirm an association in children with recurrent pharyngotonsillitis, acute rhinosinusitis and community-acquired pneumonia.

CONCLUSIONS

Maintenance of adequate vitamin D status may be an effective and inexpensive prophylactic method against some RTIs, but the supplementation regimen has not been clearly defined. Further clinical trials are needed to determine the 25(OH)D concentrations associated with an increased risk of RTIs and optimal vitamin D supplementation regimen according to the type of RTI while also taking into consideration vitamin D receptor polymorphisms.

The aetiology of pharyngotonsillitis in adolescents and adults - Fusobacterium necrophorum is commonly found

Sore throat is common in primary healthcare. Aetiological studies have focused on the presence of a limited number of pathogens. The aim of the present study was to investigate the presence of a wide range of bacteria and viruses, including Fusobacterium necrophorum, in patients with pharyngotonsillitis and in asymptomatic controls. A prospective case control study was performed in primary healthcare in Kronoberg County, Sweden. Patients (n=220) aged 15 to 45 years with a suspected acute pharyngotonsillitis, and controls (n=128), were included. Nasopharyngeal and throat swabs were analysed for β-hemolytic streptococci, F. necrophorum, Mycoplasma pneumoniae, and Chlamydophila pneumoniae, and 13 respiratory viruses. Serum samples were analysed for antibodies to Epstein-Barr virus. The patient history and symptoms, including Centor score, were analysed in relation to pathogens. In 155/220 (70.5%) of the patients, as compared to 26/128 (20.3%) of the controls (p <0.001), at least one microorganism was found. Group A streptococci, F. necrophorum, and influenza B virus were the three most common findings, and all significantly more common in patients than in controls (p <0.001, p 0.001, and p 0.002, respectively). Patients with F. necrophorum only (n=14) displayed a lower Centor score than patients with Group A streptococcus only (n=46), but a higher score than patients with influenza B, other viruses, or no potential pathogen (Kruskal-Wallis p <0.001). A pathogen was detected in 70% of the patients, displaying a wide range of pathogens contributing to the aetiology of pharyngotonsillitis. This study supports F. necrophorum as one of the pathogens to be considered in the aetiology of pharyngotonsillitis.

Update on the clinical utility and optimal use of cefditoren

This article reviews and updates published data on cefditoren. The in vitro activity of cefditoren and its potential pharmacokinetic/pharmacodynamic adequacy to cover emerging resistance phenotypes in the present decade is reviewed. Cefditoren’s in vitro activity against most prevalent bacterial respiratory pathogens in the community and its pharmacokinetic/pharmacodynamic profile suggests a significant role for cefditoren in the treatment of respiratory tract infections. Clinical trials (in acute exacerbations of chronic bronchitis, community-acquired pneumonia, pharyngotonsillitis, and sinusitis) performed during clinical development outside Japan, mainly in adults, are reviewed, together with new clinical studies in the treatment of pharyngotonsillitis, sinusitis, and otitis media in children, mainly in Japan, for efficacy and safety assessment. The results of these studies support the adequacy of cefditoren for the treatment of community-acquired respiratory tract infections with a safety profile similar to previous oral antibiotics. From the data reviewed, it is concluded that cefditoren is an adequate option for the treatment of mild-to-moderate community-acquired respiratory infections, especially in geographical areas with a reported prevalence of phenotypes exhibiting nonsusceptibility to common oral antibiotics.