Laryngeal scleroma associated with Klebsiella pneumoniae subsp. ozaenae

Epidemiological characteristics of Klebsiella ozaenae infection and its antibiotic susceptibility: Experience of a tertiary care hospital in the Eastern Province of Saudi Arabia

BACKGROUND

Klebsiella ozaenae (K. ozaenae), a forgotten pathogen that normally colonizes the upper respiratory mucosa, can be associated with severe and invasive infections. The objectives of this study were to determine the frequency of isolation of K. ozaenae at the microbiology laboratory in a tertiary hospital and the scope of diseases associated with it and to characterize its antimicrobial susceptibility pattern.

MATERIALS AND METHODS

This cross-sectional study analyzed the retrospective data, from 2002 to 2021, on cases with laboratory-confirmed isolation of K. ozaenae at a tertiary care hospital. The primary outcome was to identify the scope of K. ozaenae infections and their antimicrobial susceptibility patterns. K. ozaenae isolation was done by cultivation on microbiological culture media, whereas its identification and antimicrobial susceptibility pattern were performed using either Microscan or Vitek automated systems. Data was gathered and analyzed in Excel. The percentage of resistance was calculated as the number of resistant isolates from the total isolates multiplied by 100. Similarly, the percentage of sensitivity was calculated as the number of sensitive isolates from total isolates multiplied by 100.

RESULTS

K. ozaenae was detected in 59 cases during the study period. K. ozaenae was associated with urinary tract infections (39%), nasal infections (18.6%), other respiratory tract infections including sinusitis, bronchiectasis, and pneumonia (16.9%), and wound infections (15.3%). It was also associated with invasive infections such as bacteremia (3.4%) and abscesses (3.4%). K. ozaenae showed susceptibility to multiple antibiotic classes, but was resistant to ampicillin, piperacillin, nalidixic acid, and nitrofurantoin. K. ozaenae isolates from urinary tract infections had higher antibiotic resistance percentage than isolates from other infections, particularly to amoxicillin/clavulanic acid (P = 0.007, 95% confidence interval [CI]: 1.84-375), ciprofloxacin (P < 0.0001, 95% CI: 4.6-111.2), and trimethoprim/sulfamethoxazole (P < 0.001, 95% CI: 3.1-63.6).

CONCLUSION

Our data show that K. ozaenae is a pathogen with a spectrum of diseases wider than expected and a unique antibiotic susceptibility pattern in urinary tract infections.

Bacteriological Quality and Biotoxin Profile of Ready-to-Eat Foods Vended in Lagos, Nigeria

A comprehensive study of bacterial and biotoxin contaminants of ready-to-eat (RTE) foods in Nigeria is yet to be reported. Hence, this study applied 16S rRNA gene sequencing and a dilute-and-shoot LC-MS/MS method to profile bacteria and biotoxins, respectively, in 199 RTE food samples comprising eko (n = 30), bread (n = 30), shawarma (n = 35), aadun (n = 35), biscuits (n = 34), and kokoro (n = 35). A total of 631 bacterial isolates, clustered into seven operational taxonomic units, namely Acinetobacter, Bacillus, Klebsiella, Proteus and Kosakonia, Kurthia, and Yokenella, that are reported for the first time were recovered from the foods. One hundred and eleven metabolites comprising mycotoxins and other fungal metabolites, phytoestrogenic phenols, phytotoxins, and bacterial metabolites were detected in the foods. Aflatoxins, fumonisins, and ochratoxins contaminated only the artisanal foods (aadun, eko, and kokoro), while deoxynivalenol and zearalenone were found in industrially-processed foods (biscuit, bread, and shawarma), and citrinin was present in all foods except eko. Mean aflatoxin (39.0 µg/kg) in artisanal foods exceeded the 10 µg/kg regulatory limit adopted in Nigeria by threefold. Routine surveillance, especially at the informal markets; food hygiene and safety education to food processors and handlers; and sourcing of high-quality raw materials are proposed to enhance RTE food quality and safeguard consumer health.

Correlation Between Nasal and Laryngeal Lesions of Rhinoscleroma in Patients of Upper Egypt

INTRODUCTION

Rhinoscleroma (RS) is a chronic granulomatous disease of URT caused by Klebsiella Rinoescleromatis. RS is considered endemic in Egypt. The nasal mucosa represents the primary region of occurrence. The disease can potentially spread to involve the larynx and trachea causing dysphonia, stridor, and airway obstruction.

OBJECTIVES

To describe various nasal and laryngeal presentations of RS in our endemic area, to correlate between these findings and to alert physicians to suspect RS in any case of unexplained nasal or laryngeal lesion.

METHODS

The study included 100 patients admitted in our otorhinolaryngolgy department (Minia University, Minia, Egypt). Patients presented with various manifestations of Rhino-pharyngo-laryngo scleroma. Diagnosis based on clinical, bacteriological, and pathological examination.

RESULTS

Patients had typical nasal stages of RS, however; only 12 % of patients had the typical described laryngeal presentations (ie, subglottic narrowing and subglottic membrane). Other patients presented with atypical laryngeal presentations (eg, unhealthy vocal folds, ventricular fold hypertrophy, and suproglottic sticky greenish discharge). There was significant correlation between nasal stages and laryngeal lesions.

CONCLUSION

RS can present with atypical laryngeal presentations in endemic areas which should be kept in mind to avoid misdiagnosis. Possible laryngeal lesions of RS can be predicted from observing associated nasal lesions.

Rhinoscleroma

CONTEXT.—

Rhinoscleroma is a rare, chronic, infectious granulomatous process involving the upper respiratory tract caused by gram-negative bacilli, Klebsiella rhinoscleromatis. The site most commonly affected is the nasopharynx; however, lesions in various other locations have been described.

OBJECTIVE.—

To review the literature for all the reported cases of rhinoscleroma in the past 5 years.

DATA SOURCES.—

Published cases of rhinoscleroma from a PubMed (National Center for Biotechnology Information, Bethesda, Maryland) search were reviewed.

CONCLUSIONS.—

Rhinoscleroma in nonendemic regions is extremely rare; however, with increased travel, immigration, and globalization, it is imperative to recognize this entity because the symptoms can be devastating and in some cases fatal. Although nasopharynx is the common site of involvement, unusual sites such as the trachea can be involved in rare cases. Rhinoscleroma can be managed effectively with a combination of antibiotics and surgical debridement and repair; however, recurrence rates do remain high.

Rhinoscleroma with Pharyngolaryngeal Involvement Caused by Klebsiella ozaenae

Rhinoscleroma is a chronic, slowly progressive granulomatous bacterial infection that is endemic to the tropical world, namely, Central America and Africa. It is occasionally seen in the United States of America (USA). It predominately affects the nasal mucosa but can also involve the rest of the upper respiratory tract. The well-known causative agent for rhinoscleroma is the bacterium Klebsiella rhinoscleromatis, a subspecies of Klebsiella pneumoniae. However, Klebsiella ozaenae can also, albeit very rarely, cause rhinoscleroma. The diagnosis is confirmed by histopathology examination that shows the characteristic Mikulicz cells, considered pathognomonic for this infection. We report a patient with histologically proven rhinoscleroma with pharyngolaryngeal involvement in whom cultures yielded Klebsiella ozaenae. To the best of our knowledge, only two cases of rhinoscleroma due to Klebsiella ozaenae have been reported in the literature to date. Our case illustrates the importance of recognizing this infection in a nonendemic setting such as the USA. A lack of awareness and a delay in the diagnosis of this disease can lead to complications including upper airway obstruction, physical deformity, and, rarely, sepsis. In addition, it must be remembered that the treatment of rhinoscleroma is challenging and requires a prolonged course of antibiotics to achieve a definite cure and avoid relapses.

Septal rhinoscleroma

Rhinoscleroma is a chronic granulomatous condition of the nose and other structures of the upper respiratory tract. Infection by the bacterium Klebsiella rhinoscleromatis is said to be the cause. A female patient aged 45 years, presented with a past history of trauma to the nose and swelling on her nose since last 1 year. There was nasal asymmetry and internal nasal examination showed a septal swelling protruding to the right nasal cavity with hypertrophied nasal mucosa and inferior turbinate. Open tip rhinoplasty approach was used to excise the mass, which examined pathologically revealing a rhinoscleroma, fibrotic infiltrative stage.

Preliminary investigation of a mice model of Klebsiella pneumoniae subsp. ozaenae induced pneumonia

In the present study, we comparatively assessed the pathophysiological mechanisms developed during lung infection of BALB/C female mice infected by an original wild type Klebsiella pneumoniae subsp. ozaenae strain (CH137) or by a referent subspecies K. pneumoniae. subsp. pneumoniae strain (ATCC10031). The mice infected with 2.10⁶ CFU K. p. subsp. pneumoniae (n = 10) showed transient signs of infection and all of them recovered. All of those infected with 1.10⁶ CFU K. p. subsp. ozaenae (n = 10) developed pneumonia within 24 h and died between 48 and 72 h. Few macrophages, numerous polymorphonuclear cells and lymphocytes were observed in their lungs in opposite to K. p. subsp. pneumoniae. In bronchoalveolar lavage, a significant increase in MIP-2, IL-6, KC and MCP-1 levels was only observed in K. p. subsp. ozaenae infected mice whereas high levels of TNF-α were evidenced with the two subspecies. Our findings indicated a lethal effect of a wild type K. p. subsp. ozaenae strain by acute pneumonia reflecting an insufficient alveolar macrophage response. This model might be of a major interest to comparatively explore the pathogenicity of K. p. subsp ozaenae strains and to further explore the physiopathological mechanisms of gram-negative bacteria induced human pneumonia.

Rhinoscleroma of the Larynx: First case report in the State of Qatar

Rhinoscleroma is a chronic slowly progressive inflammatory condition of the upper airways mostly caused by infection with Klebsiella pneumoniae subspecies rhinoscleromatis and less frequently subspecies ozaenae. The disease is uncommon in developed countries but it still exists in Africa and South America. The disease usually takes a chronic course and diagnosis, which might be delayed, depends on the isolation of the organism from the tissue and the characteristic histopathologic features. We report here a case of rhinoscleroma of the upper airways that presented as a laryngeal mass in a young Egyptian man living in Qatar. The methods of diagnosis and treatment are discussed and the relevant literature reviewed.

A multiple antibiotic and serum resistant oligotrophic strain, Klebsiella pneumoniae MB45 having novel dfrA30, is sensitive to ZnO QDs

Background

The aim of this study was to describe a novel trimethoprim resistance gene cassette, designated dfrA30, within a class 1 integron in a facultatively oligotrophic, multiple antibiotic and human serum resistant test strain, MB45, in a population of oligotrophic bacteria isolated from the river Mahananda; and to test the efficiency of surface bound acetate on zinc oxide quantum dots (ZnO QDs) as bactericidal agent on MB45.

Methods

Diluted Luria broth/Agar (10^-3) media was used to cultivate the oligotrophic bacteria from water sample. Multiple antibiotic resistant bacteria were selected by employing replica plate method. A rapid assay was performed to determine the sensitivity/resistance of the test strain to human serum. Variable region of class 1 integron was cloned, sequenced and the expression of gene coding for antibiotic resistance was done in Escherichia coli JM 109. Identity of culture was determined by biochemical phenotyping and 16S rRNA gene sequence analyses. A phylogenetic tree was constructed based on representative trimethoprim resistance-mediating DfrA proteins retrieved from GenBank. Growth kinetic studies for the strain MB45 were performed in presence of varied concentrations of ZnO QDs.

Results and conclusions

The facultatively oligotrophic strain, MB45, resistant to human serum and ten antibiotics trimethoprim, cotrimoxazole, ampicillin, gentamycin, netilmicin, tobramycin, chloramphenicol, cefotaxime, kanamycin and streptomycin, has been identified as a new strain of Klebsiella pneumoniae. A novel dfr gene, designated as dfrA30, found integrated in class 1 integron was responsible for resistance to trimethoprim in Klebsiella pneumoniae strain MB45. The growth of wild strain MB45 was 100% arrested at 500 mg/L concentration of ZnO QDs. To our knowledge this is the first report on application of ZnO quantum dots to kill multiple antibiotics and serum resistant K. pneumoniae strain.

[Tracheal scleroma and rhinoscleroma: a case report]

Scleroma is a specific granlomatous disease caused by an enterobacteria of the Klebsiella family (Klebsiella rhinoscleromatis), localized electively in the upper airways, particularly the nasal fossae, leading to the term "rhinoscleroma". Tracheal involvement is exceptional. The disease progresses slowly, leaving mutilating and stenosing scar tissue. Medical treatment using antibiotics and corticosteroids is the basic approach although surgical treatment may be needed for fibrosclerosis unresponsive to medical treatment. We report a case of rhinoscleroma which extended to the trachea. In light of this case, we examine the demographic, diagnostic, therapeutic and evolutive aspects of this disease.