Surveillance of bacteria Pseudomonas aeruginosa and MRSA associated with chronic suppurative otitis media

Role of topical antibiotic ointment in the lateral graft following underlay myringoplasty: a prospective randomised study

OBJECTIVE

The objective of this study was to compare the graft outcome and postoperative infection of with and without the use of antibiotic ointment following myringoplasty for the treatment of chronic perforations.

STUDY DESIGN

Randomized controlled trial.

MATERIAL AND METHODS

135 chronic perforations were prospectively randomized to use of antibiotic ointment group (UAO, n = 68) or no use of antibiotic ointment group (NAO, n = 67) following myringoplasty. The graft outcomes and postoperative infection were compared among two groups at 6 months.

RESULTS

At postoperative 6 months, the graft infection rate was 4.4% in the UAO group and 10.4% in the NAO group, the difference was not significant (P = 0.312).The graft success rates were 92.6% in the UAO group and 91.0% in the NAO group, the difference was not significant (P = 0.979). In the UAO group, 3 patients with purulence ear discharge resulted in a residual perforation although they received ofloxacin ear drops and intravenous antibiotic therapy treatment. In the NAO group, 6 patients with purulence ear discharge resulted in a residual perforation, only one, with mild purulence discharge was successfully treated and closed. In addition, no significant between-group differences were observed pre- (P = 0.746) or post- (P = 0.521) operative air bone gap (ABG) values or mean ABG gain (P = 0.745). However, granular myringitis with minimal moistness but without infection has been noted in 3 (4.4%) patients in the UAO group and in 5 (7.5%) in the NAO group, the difference was not significant (P = 0.699).

CONCLUSIONS

Use and non-use of antibiotic ointments for lateral packing of graft are both comparable methods following myringoplasty for postoperative infection and graft outcomes.

Molecular Characteristics, Antimicrobial Resistance, and Biofilm Formation of Pseudomonas aeruginosa Isolated from Patients with Aural Infections in Shanghai, China

PURPOSE

To investigate molecular characteristics, antimicrobial resistance, and biofilm formation ability of Pseudomonas aeruginosa strains isolated from patients with aural infections.

METHODS

Isolates (n = 199) were collected from ear discharges of patients with aural infections from January 2019 to December 2020. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute guidelines. All isolates were subjected to multilocus sequence typing (MLST) with amplification and sequencing of seven housekeeping genes. Biofilm formation and eradication were quantitatively assessed in microtiter plates. Genes associated with biofilm formation and the quinolone-resistance-determining region (QRDR) of genes gyrA and parC were investigated using polymerase chain reaction amplification and sequencing.

RESULTS

Of the 199 P. aeruginosa strains isolated, 109 (54.77%) were from females and 90 (45.23%) were from males. The isolates exhibited very low rates of resistance to most antibiotics tested, including piperacillin (1.51%), ceftazidime (0.50%), and imipenem (3.52%); however, the quinolones ciprofloxacin (80.40%) and levofloxacin (82.91%) were notable exceptions. The QRDR sequence results of the quinolone-resistant P. aeruginosa isolates showed Thr83Ile (n = 155) was the most common amino acid mutation in gyrA (n = 165), while Ser87Leu (n = 157) was widely detected in parC (n = 165). MLST analysis identified 34 sequence types (STs) with most isolates belonging to ST316 (73.87%). Almost all of the P. aeruginosa isolates (96.98%) produced biofilms and biofilm-forming genes algD (98.49%), pslD (96.98%), and pelF (96.48%) were highly prevalent.

CONCLUSION

The P. aeruginosa strains isolated from aural discharges in this study exhibited very low rates of resistance to most antibiotics tested, except for the resistance rates to quinolones, which were relatively high. The isolates also exhibited a strong biofilm formation ability and low susceptibility to eradication, indicating that more effective drugs and treatment methods are needed to combat these infections.

Biofabricated Fatty Acids-Capped Silver Nanoparticles as Potential Antibacterial, Antifungal, Antibiofilm and Anticancer Agents

The current study demonstrates the synthesis of fatty acids (FAs) capped silver nanoparticles (AgNPs) using aqueous poly-herbal drug Liv52 extract (PLE) as a reducing, dispersing and stabilizing agent. The NPs were characterized by various techniques and used to investigate their potent antibacterial, antibiofilm, antifungal and anticancer activities. GC-MS analysis of PLE shows a total of 37 peaks for a variety of bio-actives compounds. Amongst them, n-hexadecanoic acid (21.95%), linoleic acid (20.45%), oleic acid (18.01%) and stearic acid (13.99%) were found predominately and most likely acted as reducing, stabilizing and encapsulation FAs in LIV-AgNPs formation. FTIR analysis of LIV-AgNPs shows some other functional bio-actives like proteins, sugars and alkenes in the soft PLE corona. The zone of inhibition was 10.0 ± 2.2-18.5 ± 1.0 mm, 10.5 ± 2.5-22.5 ± 1.5 mm and 13.7 ± 1.0-16.5 ± 1.2 against P. aeruginosa, S. aureus and C. albicans, respectively. LIV-AgNPs inhibit biofilm formation in a dose-dependent manner i.e., 54.4% ± 3.1%-10.12% ± 2.3% (S. aureus), 72.7% ± 2.2%-23.3% ± 5.2% (P. aeruginosa) and 85.4% ± 3.3%-25.6% ± 2.2% (C. albicans), and SEM analysis of treated planktonic cells and their biofilm biomass validated the fitness of LIV-AgNPs in future nanoantibiotics. In addition, as prepared FAs rich PLE capped AgNPs have also exhibited significant (p < 0.05 *) antiproliferative activity against cultured HCT-116 cells. Overall, this is a very first demonstration on employment of FAs rich PLE for the synthesis of highly dispersible, stable and uniform sized AgNPs and their antibacterial, antifungal, antibiofilm and anticancer efficacy.

Bacteriological Profile of Chronic Suppurative Otitis Media and Antibiotic Susceptibility in a Tertiary Care Hospital in Shanghai, China

OBJECTIVE

Chronic suppurative otitis media (CSOM) is mostly caused by bacterial infection of the middle ear and antibiotics are generally used empirically, which may lead to the emergence of resistant bacterial strains. The objective of the study is to assess the bacteriological profile of and evaluate the antibiotic susceptibility of strains isolated in a tertiary care hospital in Shanghai, China.

METHODS

This study included 289 individuals with clinical diagnosis of CSOM. Middle ear purulent discharge was obtained with sterile swabs and cultured for bacterial pathogens. The susceptibility of the isolated microorganisms to antibiotics was assessed by a microdilution method.

RESULTS

Bacterial pathogens were found in 223 (77.2%) of the 289 cases. A total of 236 strains were isolated. Staphylococcus aureus was the commonest bacteria (44.9%) followed by Pseudomonas aeruginosa (16.9%) and coagulase-negative Staphylococcus (8.5%). There were 18.9% methicillin-resistant S aureus (MRSA) among the obtained S aureus organisms. Multidrug-resistant P aeruginosa was found in 4 patients, making up 10% of all detected P aeruginosa. Staphylococcus aureus showed highest susceptibility to vancomycin (100%), then gentamicin (98.1%) and rifampicin (97.2%) and was most resistant to penicillin (61.3%) and erythromycin (50%). All isolated P aeruginosa showed susceptibility to piperacillin, piperacillin/tazobactam, and meropenem. High degree of resistance in P aeruginosa was observed toward levofloxacin (42.5%), ciprofloxacin (40%), and ceftriaxone (30%).

CONCLUSION

The high prevalence of MRSA and fluoroquinolone-resistant P aeruginosa indicated cephalosporins and fluoroquinolone as primary empirical antibiotic drugs in CSOM to be cautiously used. In order to reduce the incidence of resistant strains and promote effective usage of antibiotics, all aural discharges should be cultured to determine antibacterial susceptibility patterns before treatment.

Bayesian analysis of two methods MALDI-TOF-MS system and culture test in otomycosis infection

Objective

Identification of otomycotic fungi using matrix-assisted laser desorption ionization (MALDI) time of flight (TOF) mass spectroscopy (MS) and to quantify pervasive errors with Bayes rule; values of sensitivity and specificity of culture test and MALDI-TOF-MS method are quantified.

Method

Fungi cultured ear discharge samples were identified with culture test and MALDI-TOF-MS system. Minimum inhibitory concentration (MIC) or MEC (minimum effective concentration) for 6 antifungals were determined by antifungal susceptibility testing in vitro. With Bayes rule, sensitivity and specificity of both MALDI-TOF MS and culture test methods were computed.

Results

Cultures yielded 42 fungal isolates which were confirmed as species (specified against each species) belonging to 8 genera, A. niger 22, Candida sp. 7, A. fumigatus 3, A. flavus 3, mixed Aspergillus sp. 3, Mucor sp. 2, Rhizopus sp. 1, and Scopulariopsis sp.1; and MALDI-TOF-MS system also confirmed those isolates. In vitro antifungal susceptibility testing with terms of MIC 50 and MIC 90, isolates fungi were highly susceptible to 6 antifungals; and caspofungin was the most active antifungal. The high value of specificity 84.6%, suggested a limited loss of confidence on the culture test at the absence of an infection, in comparison to MALDI-TOF-MS. Sensitivity of the culture test was 87.5%; this high figure strongly approves the culture test to be the dependable method for the otomycosis diagnosis, when the infection is stable.

Conclusion

Based on sensitivity and specificity together the culture test could be done in face of the gold-standard MALDI-TOF-MS system the estimating both methods.

Molecular characterization and antimicrobial susceptibility of Staphylococcus aureus isolated from children with acute otitis media in Liuzhou, China

BACKGROUND

There have been few studies focused on the prevalence, bacterial etiology, antibiotic resistance, and genetic background of Staphylococcus aureus (S. aureus) in children with acute otitis media (AOM) in China.

METHODS

A retrospective study was conducted in Liuzhou Maternity and Child Healthcare Hospital. Patients younger than 18 years diagnosed with AOM were enrolled in the study. Middle ear fluid specimens were collected and cultured for bacterial pathogens. The antibiotic susceptibility, virulence genes, macrolide resistant genes and sequence types of S. aureus were identified.

RESULTS

From January 1, 2013 to December 31, 2015, a total of 228 cases of AOM were identified. Pathogenic bacteria were positive in 181 (79.4%) of 228 specimens. Streptococcus pneumoniae was the most common bacteria (36.4%), followed by S. aureus (16.2%). Among the 37 S. aureus isolates, 12 (23.5%) were methicillin-resistant S. aureus (MRSA), and 25 (77.5%) were methicillin-susceptible S. aureus (MSSA). A total of 23 isolates (62.2%) were resistant to erythromycin, 40.5% of isolates were resistant to clindamycin, and 37.8% isolates were resistant to tetracycline. Twenty-three isolates were multi-drug resistant (MDR) S. aureus. Eighteen isolates carried the pvl gene. Up to 22 (59.4%) isolates expressed ermA gene, 8 (21.6%) isolates expressed both ermA and ermC genes, and only 8.1% expressed ermB. Among all S.aureus isolates, 7 sequence types (STs) were identified by multilocus sequence typing (MLST). The most common ST was ST59 (16/37, 43.2%), followed by ST45 (7/37, 18.9%) and ST30 (7/37, 18.9%). The predominant MSSA isolates were ST59-t437-MSSA (5/25, 20.0%), the prevailing MRSA isolates were Taiwan related strains ST59-SCCmec-IVa/V (5/12, 41.6%).

CONCLUSIONS

S. aureus was the second most common cause for AOM in children in Liuzhou. Most of the S. aureus was MDR which carried a high proportion of ermA and ermC gene. CA-MRSA (ST59-SCCmec-IV/V-t437) is circulating in children with AOM. These findings support continued surveillance of S. aureus infections in children with AOM in both communities and hospitals.

Microbial otitis media: recent advancements in treatment, current challenges and opportunities

Otitis media (OM) is a common disease affecting humans, especially paediatric populations. OM refers to inflammation of the middle ear and can be broadly classified into two types, acute and chronic. Bacterial infection is one of the most common causes of OM. Despite the introduction of vaccines, the incidence of OM remains significantly high worldwide. In this mini-review article, we discuss the recent treatment modalities for OM, such as suspension gel, transcutaneous immunization, and intranasal and transtympanic drug delivery, including therapies that are currently undergoing clinical trials. We provide an overview of how these recent advancements in therapeutic strategies can facilitate the circumvention of current treatment challenges involving preadolescence soft palate dysfunction, biofilm formation, tympanic membrane (ear drum) barrier and the attainment of efficacious drug concentrations in the middle ear. While traditional first-line immunization strategies are generally not very efficacious against biofilms, new technologies that use transdermal or intranasal drug delivery via chitosan-PsaA nanoparticles have shown promising results in experimental animal models of OM. Sustained drug delivery systems such as penta-block copolymer poloxamer 407-polybutylphosphoester (P407-PBP) or poloxamer 407 (e.g. OTO-201, with the brand name 'OTIPRIO') have demonstrated that treatments can be reduced to a single topical application. The emergence of effective new treatment modalities opens up promising new avenues for the treatment of OM that could lead to improved quality of life for many children and their families.