Optimal site for throat culture: tonsillar surface versus posterior pharyngeal wall

The Effects of Smoking on Human Pharynx Microbiota Composition and Stability

The oral microbiota is essential to the health of the host, yet little is known about how it responds to disturbances. We examined the oropharyngeal microbiota of 30 individuals over 40 weeks. As the oropharynx is an important gateway to pathogens, and as smoking is associated with increased incidence and severity of respiratory infections, we compared the microbiota of smokers and nonsmokers to shed light on its potential for facilitating infections. We hypothesized that decreased species diversity, decreased community stability, or increased differences in community structure could facilitate invading pathogens. We found that smoking is associated with reduced alpha diversity, greater differences in community structure, and increased environmental filtering. The effects of short-term perturbations (antibiotic use and participants exhibiting cold symptoms) were also investigated. Antibiotic use had a negative effect on alpha diversity, irrespective of smoking status, and both antibiotic use and cold symptoms were associated with highly unique bacterial communities. A stability analysis of models built from the data indicated that there were no differences in local or global stability in the microbial communities of smokers, compared to nonsmokers, and that their microbiota are equally resistant to species invasions. Results from these models suggest that smoker microbiota are perturbed but characterized by alternative stable states that are as stable and invasion-resistant as are the microbiota of nonsmokers. Smoking is unlikely to increase the risk of infectious disease through the altered composition and ecological function of the microbiota; this is more likely due to the effects of smoking on the local and systemic immune system. IMPORTANCE Smoking is associated with an increased risk of respiratory infections. Hypothetically, the altered community diversity of smokers' pharyngeal microbiota, together with changes in their ecological stability properties, could facilitate their invasion by pathogens. To address this question, we analyzed longitudinal microbiota data of baseline healthy individuals who were either smokers or nonsmokers. While the results indicate reduced biodiversity and increased species turnover in the smokers' pharyngeal microbiota, their ecological stability properties were not different from those of the microbiota of nonsmokers, implying, in ecological terms, that the smokers' microbial communities are not less resistant to invasions. Therefore, the study suggests that the increased propensity of respiratory infections that is seen in smokers is more likely associated with changes in the local and systemic immune system than with ecological changes in the microbial communities.

The profile of microorganisms that associate with acute tonsillitis in children and their antibiotics sensitivity pattern in Nigeria

Acute tonsillitis remains one of the common childhood diseases in developing countries. Prompt and appropriate treatment based on the knowledge of the causative microbiota and their antimicrobial susceptibility pattern will improve the treatment outcome and reduce time and resources spent on treatment. This study aims to determine the pattern of microbiota isolates and their susceptibility pattern. The study was a combination of the retrospective and cross-sectional method. The medical records of children treated for tonsillitis were retrieved, as well as those of children who presented with acute tonsillitis for the study. Interviewer-administered questionnaire was used to collect data, as well as document information retrieved from their medical record: presenting symptoms, treatments received. Swab sample was taken for culture and antibiotic susceptibility test. Out of the 72 swab cultures, 29 (40.3%) yielded insignificant growth of gram positive cocci. A total of nine (9) different isolates were obtained from all the significant swab cultures. Streptococcus species (13, 18.6%) and staphylococcus species (11, 15.3%) were the commonest isolates. Imipenem and levofloxacin revealed high level of susceptibility, while Ampicillin and Cefexine recorded high resistance rates. The proportion of the cultures that were positive of significant growth, the proportion of these positive isolates that were Streptococcus spp. and varied sensitivity pattern obtained underpinned the importance to advocate for culture isolates and susceptibility pattern guided treatment. These will not only an efficient approach to management of acute tonsillitis, but also a strong approach towards effective implementation of antibiotic stewardship.

Clinical application of an intelligent oropharyngeal swab robot: implication for the COVID-19 pandemic

Coronavirus disease 2019 (COVID-19), caused by infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is transmitted through respiratory droplets and close contact [1–4]. To diagnose COVID-19, oropharyngeal swab (OP swab) sampling is widely used for viral nucleic acid detection [3]. However, healthcare workers who perform OP swab are at high risk of infection due to aerosol from patients during the process of sampling. And the quality of manual OP swabs is inconsistent among different collectors, which may lead to misdiagnosis [5]. Use of a remote-controlled OP swab robot has the potential to avoid close contact between healthcare workers with patients, and thus reduce the risk of SARS-CoV-2 infection during sampling. Here, we invented a robotic sampling (RS) system and evaluated the safety and efficacy of this system on OP swab sampling during the period of pandemic.

Clinical application of the safety and effectiveness of an intelligent oropharyngeal-swab robot, and its implication for the COVID-19 pandemichttps://bit.ly/2BUsV55

Carriage of antibiotic-resistant Haemophilus influenzae strains in children undergoing adenotonsillectomy

Haemophilus influenzae is one of the major pathogenic bacteria in upper respiratory tract of children. In this study, the presence of various H. influenzae genotypes were followed-up for at least 13 weeks, starting from one week before surgery. Forty-one children with chronic adenoid hypertrophy were prospectively enrolled to the study. The consecutive swabs of adenoid and tonsils, two before adenotonsillectomy and two after the surgery together with homogenates of adenotonsillar tissues and lysates of the CD14(+) cells fraction were acquired from 34 children undergoing adenotonsillectomy. Up to ten isolates from each patient at each collection period were genotyped using a PFGE method and their capsular type and antibiotic susceptibility was determined. Of the 1001 isolates examined, we identified 325 isolates grouped into 16 persistent genotypes, which colonized throats for more than seven weeks and were not eliminated by the surgery. The other 506 isolates grouped into 48 transient genotypes that had been eliminated by the surgery. The resistance to ampicillin were found in 23.8% of the transient strains, and 4.7% of the newly acquired strains following the surgical intervention. In contrast, none of the persistent strains were resistant to ampicillin; however, these strains showed apparently higher level of resistance to co-trimoxazole when compared to transient strains. The transient and persistent strains did not significantly differ in bacterial viability in the biofilms formed in vitro. Some of the strains were identified in two or three different patients and were considered as the strains circulating in the region between 2010 and 2012.

Management of acute streptococcal pharyngitis: still the subject of controversy

Although most cases of acute pharyngitis are viral in origin, antibiotics are overused in its treatment. Streptococcus pyogenes (group A streptococcus, GAS), the principal bacterial pathogen of acute sore throat, is responsible for merely 5–30% of cases. Moreover, GAS pharyngitis is currently the only commonly occurring form of acute pharyngitis for which antibiotic therapy is definitely indicated. Therefore the differentiation between GAS pharyngitis and that of viral etiology is crucial. Accordingly, scientific societies as well as respected advisory bodies in Europe and North America, issued guidelines for the management of acute pharyngitis with the aim of minimizing unnecessary antibiotic prescriptions in its treatment. The aim of this review work is to confront the state of the art in acute GAS pharyngitis diagnosis and treatment with different approaches to its management represented by current European and North American guidelines. Although based on scientific evidence, international guidelines differ substantially in opinions whether GAS pharyngitis diagnosis should be based on microbiological testing, clinical algorithm or a combination of both. On the other hand, some European guidelines consider GAS pharyngitis to be a mild, self-limiting disease that does not require a specific diagnosis or antimicrobial treatment except in high-risk patients. There is an agreement among guidelines that if antibiotic therapy is indicated, phenoxymethyl penicillin should be the drug of choice to treat GAS pharyngitis.

Guideline for the management of acute sore throat

The European Society for Clinical Microbiology and Infectious Diseases established the Sore Throat Guideline Group to write an updated guideline to diagnose and treat patients with acute sore throat. In diagnosis, Centor clinical scoring system or rapid antigen test can be helpful in targeting antibiotic use. The Centor scoring system can help to identify those patients who have higher likelihood of group A streptococcal infection. In patients with high likelihood of streptococcal infections (e.g. 3-4 Centor criteria) physicians can consider the use of rapid antigen test (RAT). If RAT is performed, throat culture is not necessary after a negative RAT for the diagnosis of group A streptococci. To treat sore throat, either ibuprofen or paracetamol are recommended for relief of acute sore throat symptoms. Zinc gluconate is not recommended to be used in sore throat. There is inconsistent evidence of herbal treatments and acupuncture as treatments for sore throat. Antibiotics should not be used in patients with less severe presentation of sore throat, e.g. 0-2 Centor criteria to relieve symptoms. Modest benefits of antibiotics, which have been observed in patients with 3-4 Centor criteria, have to be weighed against side effects, the effect of antibiotics on microbiota, increased antibacterial resistance, medicalisation and costs. The prevention of suppurative complications is not a specific indication for antibiotic therapy in sore throat. If antibiotics are indicated, penicillin V, twice or three times daily for 10 days is recommended. At the present, there is no evidence enough that indicates shorter treatment length.

Approach to a child with sore throat

Sore throat is one of the common reasons for outpatient and emergency visits among children. It could be because of several etiologies; of these bacterial pharyngitis is the most important. Major challenge for the clinician is to diagnose group A beta hemolytic streptococcus (GABHS) pharyngitis and diphtheria, which are associated with serious complications. Throat swab smear with culture and rapid antigen tests are useful for making the diagnosis but the later may not be available in resource poor settings. Many clinical scores have been devised to diagnose GABHS with variable success but usually clinical features, epidemiological criteria and expert clinical judgment with or without supportive investigations indicate need for antibiotics. A child with sore throat and toxic look may have diphtheria or parapharyngeal/retropharyngeal abscess, and therefore should be hospitalized.

Evaluation of amoxicillin plasma and tissue levels in pediatric patients undergoing tonsillectomy

OBJECTIVE

Tonsillectomy is the most common surgery performed in the pediatric and young adult populations. Although recent guidelines based on meta-analysis suggest that perioperative chemoprophylaxis plays a role in reducing bacteraemia-related post-tonsillectomy complications, there is no evidence or agreement upon which specific antibiotic, dosage or administration route should be preferred. Since few previous studies have assessed the effectiveness of prophylaxis by direct measurement of antibiotic levels both in plasma and tissue, we designed an experimental study to quantitatively evaluate amoxicillin concentrations in children ready for tonsillectomy and compare these plasma and tissue levels with the Minimal Inhibitory Concentrations (MIC) of the bacteria more commonly involved in the upper airway infections.

METHODS

Thirty-three pediatric patients under 14 years of age (median 5.0, IQR 4-7, range 3-11; M:F 18:15) with recurrent tonsillitis were treated with 3 doses (established on patient's weight) of amoxicillin-clavulanic acid given orally the day before plus a further dose 2h before tonsillectomy. Amoxicillin concentrations on both homogenated tonsillar cores and plasma were measured by HPLC-UV. Bacterial epidemiology and susceptibility were derived respectively from survey data collected by Microbiology Unit and MIC according to the National Committee for Clinical Laboratory Standards (NCCLS).

RESULTS

Median plasma and tissue amoxicillin concentrations were respectively 4.7 microg/ml (IQR 2.1-8.0; min-max 0.4-14.3) and 1.1 microg/g (IQR 0.4-2.1; min-max 0.4-12.9), considerably below the selected target MIC of pathogens involved in the upper respiratory tract infections (S. aureus, H. influenzae, M. catarrhalis). 20 Children showed undetectable amoxicillin levels in one or both tonsils. Interestingly, 7 out of these patients (35%) had plasma concentrations higher than the target MIC (8 microg/ml). No patient displayed plasma concentrations under the limit of sensitivity of the method. Poor core-plasma and left-right core correlation was observed among patients, suggesting that fibrosis developed after recurrent tonsillitis may hamper antibiotic penetration.

CONCLUSIONS

Based upon direct measurement of antibiotic levels in plasma and tissue, this study suggests that a revision of the oral prophylaxis in children is required in order to reduce microbial charge in the operative field and accordingly improve the recovery after tonsillectomy.

Intracellular persisting Staphylococcus aureus is the major pathogen in recurrent tonsillitis

Background

The two major indications for tonsillectomy are recurrent tonsillitis (RT) and peritonsillar abscess (PTA). Unlike PTAs, which are primarily treated surgically, RT is often cured by tonsillectomy only after a series of failed drug therapy attempts. Although the bacteriological background of RT has been studied, the reason for the lack of success of conservative therapeutic approaches is not well understood.

Methods

In a prospective study, tonsil specimens from 130 RT patients and 124 PTA patients were examined for the presence of extra- and intracellular bacteria using antibiotic protection assays. Staphylococcus aureus isolates from RT patients were characterized by pulsed-field gel electrophoresis (PFGE), spa-typing and MSCRAMM-gene-PCR. Their ability for biofilm formation was tested and their cell invasiveness was confirmed by a flow cytometric invasion assay (FACS), fluorescent in situ hybridization (FISH) and immunohistochemistry.

Findings

S. aureus was the predominant species (57.7%) in RT patients, whereas Streptococcus pyogenes was most prevalent (20.2%) in PTA patients. Three different assays (FACS, FISH, antibiotic protection assay) showed that nearly all RT-associated S. aureus strains were located inside tonsillar cells. Correspondingly, the results of the MSCRAMM-gene-PCRs confirmed that 87% of these S. aureus isolates were invasive strains and not mere colonizers. Based upon PFGE analyses of genomic DNA and on spa-gene typing the vast majority of the S. aureus isolates belonged to different clonal lineages.

Conclusions

Our results demonstrate that intracellular residing S. aureus is the most common cause of RT and indicate that S. aureus uses this location to survive the effects of antibiotics and the host immune response. A German translation of the Abstract is provided as supplementary material (Abstract S1).