Endogenous Endophthalmitis Caused by Carbapenem-Resistant Hypervirulent Klebsiella Pneumoniae: A Case Report and Literature Review

[Surgical therapy and pathogen detection in endogenous endophthalmitis : Analysis of data from five German eye hospitals]

BACKGROUND

Endogenous endophthalmitis results from hematogenous spread of bacterial or fungal infection in severely diseased patients. Specific systemic and intraocular therapy is required. The basis for this treatment is causal pathogen detection in blood culture or vitreous sample. However, functional results are limited.

OBJECTIVE

The current article provides practical hints for surgical therapy and pathogen detection in patients with endogenous endophthalmitis.

METHODS

A retrospective analysis of anonymous data of 68 male and female patients from 2018-2023 from five ophthalmology clinics in Germany was performed.

RESULTS

Mean age of affected patients was 71.4 years (31-96 years). Surgical therapy included pars plana vitrectomy (ppV) and intravitreal injection (IVOM). In 44 of 68 patients (65%), 1-3 surgeries were performed, 4-6 surgeries were required in 14/68 (21%) of patients, and 10 or more surgeries were required in 4/68 patients (6%). Pathogen detection was possible in 34% of vitreous specimens and in 11% of anterior chamber samples. Mean initial visual acuity was logMAR 1.5. After treatment and a mean follow-up of 2.5 months, mean visual acuity was logMAR 1.3. Preanalytical methods for specimen collection like the Freiburg endophthalmitis set to optimize pathogen detection are presented.

CONCLUSION

Severe inflammatory intraocular reactions in endogenous endophthalmitis necessitate a combination of ppV and repeated IVOM. In addition to providing a vitreous sample, ppV also serves to remove inflammatory fibrin membranes. Early pars plana vitrectomy with specific antibiotic or antifungal therapy should be sought in addition to the focus search and systemic therapy.

"Superbugs" with hypervirulence and carbapenem resistance in Klebsiella pneumoniae: the rise of such emerging nosocomial pathogens in China

Although hypervirulent Klebsiella pneumoniae (hvKP) can produce community-acquired infections that are fatal in young and adult hosts, such as pyogenic liver abscess, endophthalmitis, and meningitis, it has historically been susceptible to antibiotics. Carbapenem-resistant K. pneumoniae (CRKP) is usually associated with urinary tract infections acquired in hospitals, pneumonia, septicemias, and soft tissue infections. Outbreaks and quick spread of CRKP in hospitals have become a major challenge in public health due to the lack of effective antibacterial treatments. In the early stages of K. pneumoniae development, HvKP and CRKP first appear as distinct routes. However, the lines dividing the two pathotypes are vanishing currently, and the advent of carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) is devastating as it is simultaneously multidrug-resistant, hypervirulent, and highly transmissible. Most CR-hvKP cases have been reported in Asian clinical settings, particularly in China. Typically, CR-hvKP develops when hvKP or CRKP acquires plasmids that carry either the carbapenem-resistance gene or the virulence gene. Alternatively, classic K. pneumoniae (cKP) may acquire a hybrid plasmid carrying both genes. In this review, we provide an overview of the key antimicrobial resistance mechanisms, virulence factors, clinical presentations, and outcomes associated with CR-hvKP infection. Additionally, we discuss the possible evolutionary processes and prevalence of CR-hvKP in China. Given the wide occurrence of CR-hvKP, continued surveillance and control measures of such organisms should be assigned a higher priority.

Carbapenemase-producing Enterobacteriaceae and vancomycin-resistant Enterococcus faecium: The value of a computerized monitoring system to limit their spread

OBJECTIVE

To quickly implement Infection Prevention and Control measures ("search and isolate" strategy), a computerized monitoring system for carbapenemase-producing Enterobacteriaceae (CPE) and Vancomycin-resistant Enterococcus faecium (VRE) carrier and contact patients has been developed in our hospital since 2014. The objectives were to assess the value of a computerized monitoring system in CPE and VRE management and to evaluate the relevance of extended monitoring of all contact patients.

METHODS

Using the data extracted from the computerized system, we conducted a descriptive analysis of CPE and VRE carriers detected from 2004 to 2019 and CPE and VRE extensive contact patients (when hospital stay overlapped with the stay of a carrier in the same unit) from 2014 to 2019.

RESULTS

Between 2015 and 2019 (microbiological data only available during this period), 113 CPE and 558 VRE carriers were registered in the database (DB). Among them, 33.9% CPE and 12.8% VRE carriers were infected (p = 0.02). The most frequent infections were urinary tract infections (52.0%), bloodstream infections (20.0%) and pneumonia (16.0%). Close to 8000 (7679) extended contact patients were exposed. Only 26.2% of them were removed from the DB because of appropriate negative post-exposure rectal screenings. No rectal screening was performed in 33.5% of contact patients. Between 2014 and 2019, 16 outbreaks occurred. The proportion of infected carriers differed significantly between outbreaks (index cases) and non-epidemic episodes (50.0% and 20.5% respectively, p = 0.03). The detection system was able to control diffusion in 99.7% of readmissions of known carriers. Among the 360 readmissions detected by the system, only one was involved in an outbreak due to non-compliance with infection control measures.

CONCLUSION

Given the low screening completion rate (26.2%) and the low detection rate (1.3%), extended monitoring of contact patients does not seem relevant. After five years of use, the computerized monitoring system has demonstrated its effectiveness in terms of responsiveness and limitation of the spread of multidrug-resistant organisms.

Case report: A case of acute postoperative endophthalmitis following penetrating keratoplasty due to carbapenem-resistant Klebsiella Pneumoniae and literature review

A 22-year-old lady underwent penetrating keratoplasty for serious keratoconus. The following day, it was complicated by the development of infectious endophthalmitis. The source of infection was identified as carbapenem-resistant Klebsiella pneumoniae. The donor corneal button might be playing a role in infection transmission due to carbapenem-resistant Klebsiella pneumoniae in a sputum culture when the donor was still alive. Nosocomial infections were typically severe, rapidly progressive, and difficult to treat. Finally, the patient underwent therapeutic penetrating keratoplasty again with complete resolution of the infection.

Clinical and Microbiological Characteristics of Endogenous Klebsiella pneumoniae Endophthalmitis in a Tertiary Hospital in Shanghai, China

PURPOSE

To investigate the clinical features of endogenous Klebsiella pneumoniae endophthalmitis (EKPE) and the molecular characteristics of pathogenic K. pneumoniae.

METHODS

A retrospective study was conducted between January 2014 and January 2021. Clinical data were extracted. K. pneumoniae isolates cultured from EKPE patients' specimens were characterized by antimicrobial susceptibility testing, multilocus sequence typing, capsular serotyping, and virulence gene profiles. Virulence phenotypes were confirmed by mouse lethality assay.

RESULTS

Thirty-nine patients (47 eyes) were diagnosed with EKPE. Administration of systemic antibiotics and eye treatment within 24 hours of ocular symptom onset was statistically associated with better visual outcomes (p = .007). Sixteen K. pneumoniae isolates were collected, three of which were carbapenem-resistant and avirulent. Only salmochelin encoding gene was harbored by all isolates.

CONCLUSIONS

Systemic and eye treatment administered within 24 hours from the onset improves visual prognosis. Besides hypervirulent strains, avirulent carbapenem-resistant K. pneumoniae can cause EKPE.

Gram-Negative Endogenous Endophthalmitis: A Systematic Review

Background: Gram-negative bacteria are causative agents of endogenous endophthalmitis (EBE). We aim to systematically review the current literature to assess the aetiologies, risk factors, and early ocular lesions in cases of Gram-negative EBE. Methods: All peer-reviewed articles between January 2002 and August 2022 regarding Gram-negative EBE were included. We conducted a literature search on PubMed and Cochrane Controlled Trials. Results: A total of 115 studies and 591 patients were included, prevalently Asian (98; 81.7%) and male (302; 62.9%). The most common comorbidity was diabetes (231; 55%). The main aetiologies were Klebsiella pneumoniae (510; 66.1%), Pseudomonas aeruginosa (111; 14.4%), and Escherichia coli (60; 7.8%). Liver abscesses (266; 54.5%) were the predominant source of infection. The most frequent ocular lesions were vitreal opacity (134; 49.6%) and hypopyon (95; 35.2%). Ceftriaxone (76; 30.9%), fluoroquinolones (14; 14.4%), and ceftazidime (213; 78.0%) were the most widely used as systemic, topical, and intravitreal anti-Gram-negative agents, respectively. The most reported surgical approaches were vitrectomy (130; 24.1%) and evisceration/exenteration (60; 11.1%). Frequently, visual acuity at discharge was no light perception (301; 55.2%). Conclusions: Gram-negative EBEs are associated with poor outcomes. Our systematic review is mainly based on case reports and case series with significant heterogeneity. The main strength is the large sample spanning over 20 years. Our findings underscore the importance of considering ocular involvement in Gram-negative infections.

Epidemiological characteristics and molecular evolution mechanisms of carbapenem-resistant hypervirulent Klebsiella pneumoniae

Carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP), a type of Klebsiella pneumoniae (KP) that exhibits hypervirulence and carbapenem resistance phenotypes, can cause severe infections, both hospital- and community-acquired infections. CR-hvKP has brought great challenges to global public health and is associated with significant morbidity and mortality. There are many mechanisms responsible for the evolution of the hypervirulence and carbapenem resistance phenotypes, such as the horizontal transfer of the plasmid carrying the carbapenem resistance gene to hypervirulent Klebsiella pneumoniae (hvKP) or carbapenemase-producing Klebsiella pneumoniae (CRKP) acquiring a hypervirulence plasmid carrying a virulence-encoding gene. Notably, KP can evolve into CR-hvKP by acquiring a hybrid plasmid carrying both the carbapenem resistance and hypervirulence genes. In this review, we summarize the evolutionary mechanisms of resistance and plasmid-borne virulence as well as the prevalence of CR-hvKP.

Infection Sources and Klebsiella pneumoniae Antibiotic Susceptibilities in Endogenous Klebsiella Endophthalmitis

Endogenous endophthalmitis is an uncommon intraocular infection with potentially devastating consequences on vision. Klebsiella pneumoniae is highly prevalent in East Asian countries, with an increasing incidence recently worldwide. This retrospective study investigates infection sources and antibiotic susceptibilities of K. pneumoniae in patients with endogenous K. pneumoniae endophthalmitis (EKE) in Northern Taiwan. One hundred and fifty-seven patients with EKE were reviewed between January 1996 and April 2019. Pyogenic liver abscess (120/157, 76.4%) was the most common infection source, followed by pneumonia (13, 8.3%), urinary tract infection (7, 4.5%), and intravenous drug use (4, 2.5%). Bilateral involvement was identified in 12.1% (19/157) of patients, especially in patients with pyogenic liver abscess (16/120, 13.3%), pneumonia (2/13, 15.4%), and urinary tract infection (1/7, 14.3%). The antibiotic susceptibility rates were 98.1%, 92.5%, 97.5%, 96.8%, 100%, 99.3%, and 100% for amikacin, cefuroxime, ceftazidime, ceftriaxone, carbapenems, ciprofloxacin, and levofloxacin, respectively. Four extended-spectrum β-lactamase-producing multidrug-resistant (MDR) K. pneumoniae isolates were identified. In conclusion, pyogenic liver abscess was the major infection source in EKE. In addition, K. pneumoniae was still highly susceptible to ceftazidime and amikacin, and the MDR K. pneumoniae isolates were not common in EKE.

Occurrence of Hypervirulent Klebsiella pneumoniae in Clinical Settings and Lytic Potential of Bacteriophages Against the Isolates

Background: Antibiotic resistance is a major health hazard around the globe. Hypervirulent Klebsiella Pneumoniae (hvKp) is associated with hospital-acquired and community-acquired infections. Since there is a lack of new antibiotics against multidrug-resistant (MDR) pathogens, phage therapy might provide an alternative approach to confer antibiotic resistance. Objectives: This study aimed to estimate the occurrence of hvKp and characterize the bacteriophage against the hvKp prevalence in clinical settings, which might be used as an alternative to antibiotics. Methods: Different clinical samples (n = 50) were collected to isolate K. pneumoniae, and the assessment of multidrug resistance was carried out based on the Clinical and Laboratory Standards Institute guidelines (2020). The bacteriophage was isolated from hospital waste, and the double agar overlay method was used for phage purification and propagation. Spot test and one-step curve were performed to determine host-phage interactions. For the evaluation of phage stability in environmental conditions, the phage was incubated at various ranges of temperature, pH, and chloroform. Results: Out of the collected samples, 22 (44%) isolates were confirmed as K. pneumoniae. Among confirmed K. pneumoniae isolates, a total of 11 (50%) isolates were detected as hvKp. Moreover, 14 (64%) isolates were detected as MDR, out of which 5 (35%) isolates were among hvKp phenotypes. Maximum resistance was observed against ampicillin (86%) followed by ceftriaxone (81%) which was the highest among cephalosporins. The isolated bacteriophage showed a broad host range, short latent period, and stability. Overall, 16 isolates (85%) of K. pneumoniae were susceptible to phage infection, among which 12 isolates were MDR (75%); however, all 5 (100%) hvKp isolates were susceptible to phage infection. One-step growth analysis revealed a burst size of 190 phages/host bacterial cells with a short latent period of 24 minutes. Conclusions: Altogether, the significant prevalence of hvKp was estimated in clinical settings, and the isolated bacteriophage showed significant lytic activity as it killed all the hvKp strains. Phage therapy might be exploited and used as a potential alternative therapeutic approach against infections caused by this resistant pathogen.

Susceptibility of bacterial endophthalmitis isolates to vancomycin, ceftazidime, and amikacin

Bacterial endophthalmitis is a rare intraocular infection, and prompt administration of intravitreal antibiotics is crucial for preventing severe vision loss. The retrospective study is to investigate the in vitro susceptibility to the antibiotics vancomycin, amikacin, and ceftazidime of bacterial endophthalmitis isolates in specimens at a tertiary referral center from January 1996 to April 2019 in Taiwan. Overall, 450 (49.9%) isolates were Gram positive, 447 (49.6%) were Gram negative, and 4 (0.4%) were Gram variable. In Gram-positive isolates, coagulase-negative staphylococci were the most commonly cultured bacteria (158, 35.1%), followed by Streptococci (100, 22.2%), Enterococci (75, 16.7%), and Staphylococcus aureus (70, 15.6%). In Gram-negative isolates, they were Klebsiella pneumoniae (166, 37.1%) and Pseudomonas aeruginosa (131, 29.3%). All Gram-positive organisms were susceptible to vancomycin, with the exception of one Enterococcus faecium isolate (1/450, 0.2%). Of the Gram-negative isolates, 96.9% and 93.7% were susceptible to ceftazidime and amikacin, respectively. Nine isolates (9/447, 2.0%) were multidrug-resistant Gram-negative bacteria, comprising K. pneumoniae (4/164, 2.4%), Acinetobacter baumannii (2/3, 67%), and Stenotrophomonas maltophilia (3/18, 17%). In conclusion, in vitro susceptibility testing revealed that vancomycin remains the suitable antibiotic treatment for Gram-positive endophthalmitis. Ceftazidime and amikacin provide approximately the same degree of Gram-negative coverage. Multidrug-resistant bacterial endophthalmitis was uncommon.

A case of neck abscess caused by rare hypervirulent Klebsiella pneumoniae, capsular type K20 and sequence type 420

Background

This case report describes a neck abscess caused by a strain of Hypervirulent Klebsiella pneumoniae in a middle aged man with diabetes without a history of travel to East and South East Asia. This case report is of notable significance as Hypervirulent Klebsiella pneumoniae neck abscesses are rarely seen in the UK and are very infrequently documented in individuals who have not first travelled to the high prevalence areas of East and South East Asia.

Case presentation

This case report describes a 53 year old diabetic man who contracted a Hypervirulent Klebsiella pneumoniae neck abscess which led to the development of sepsis. Klebsiella pneumoniae was cultured from blood cultures and fluid aspirated from the abscess grew the pathogen with same antimicrobial susceptibility. Hypervirulence was demonstrated after the samples were analysed, at the Antimicrobial Resistance and Healthcare Associated Infections Reference Unit Public Health England Colindale, and found to contain the K20 (rmp)A and rmpA2 virulence genes.

Discussion

Hypervirulent Klebsiella pneumoniae is a Gram-negative, encapsulated, non-motile bacillus notable for its ability to metastatically spread and cause potentially life threatening infections in otherwise healthy adults, but especially in those with diabetes. Genes responsible for the production of hyperviscous mucoid polysaccharide capsules and siderophores, such as those isolated in this case, enable the bacteria to more efficiently evade the hosts immune system and disseminate and invade surrounding and distant tissues. Data from Public Health England shows Hypervirulent Klebsiella pneumoniae are rare in the UK. A review of current literature also showed Hypervirulent Klebsiella pneumoniae almost exclusively occur in those who have traveled to East and South East Asia.

Conclusions

This case reported a rare Hypervirulent Klebsiella pneumoniae neck abscess outside of, and without travel to, East and South East Asia. This raises concerns about future, potentially life threatening, Hypervirulent Klebsiella pneumoniae infections becoming more widespread without the need for endemic travel. This concern is further exacerbated by the growing global challenge of antimicrobial resistance.

Renal abscesses and endogenous endophthalmitis due to hypermucoviscous hypervirulent Klebsiella pneumoniae (HVKP)

We describe a diabetic patient with left eye endogenous endophthalmitis due to hypervirulent hypermucoviscous Klebsiella pneumoniae (HKVP) originating from right renal abscesses. A rare source of HVKP causing endogenous endophthalmitis. Despite treatment with intravenous ceftazidime and pars plana vitrectomy, the patient required evisceration of the left eye. A high index of suspicion for endogenous endophthalmitis and awareness of the virulence and potential antibiotic resistance of HVKP strains in the community is needed to avoid vision and life-threatening consequences.

A global perspective on the convergence of hypervirulence and carbapenem resistance in Klebsiella pneumoniae

Hypervirulence and carbapenem resistance have emerged as two distinct evolutionary directions for Klebsiella pneumoniae, which pose a great threat in clinical settings. Multiple virulence factors contribute to hypervirulence, and the mechanisms of carbapenem resistance are complicated. However, more and more K. pneumoniae strains have been identified in recent years integrating both phenotypes, resulting in devastating clinical outcomes. Hypervirulent and carbapenem-resistant K. pneumoniae (CR-hvKP) emerged in the early 2010s and thereafter have become increasingly prevalent. CR-hvKP are primarily prevalent in Asia, especially China, but are reported all over the world. Mechanisms for the emergence of CR-hvKP can be summarised by three patterns: (i) carbapenem-resistant K. pneumoniae (CRKP) acquiring a hypervirulent phenotype; (ii) hypervirulent K. pneumoniae (hvKP) acquiring a carbapenem-resistant phenotype; and (iii) K. pneumoniae acquiring both a carbapenem resistance and hypervirulence hybrid plasmid. With their global dissemination, continued surveillance of the emergence of CR-hvKP should be more highly prioritised.

Surgery combined with antibiotics for the treatment of endogenous endophthalmitis caused by liver abscess

Backgrounds

Endogenous endophthalmitis is a serious disease caused by intraocular infection that can rapidly progress to cause blindness. This study evaluated the clinical features, surgical and antibiotics treatment strategies, and treatment outcomes in patients with endophthalmitis caused by liver abscess.

Methods

Between April 2014 and April 2019, the clinical data of 16 patients (19 eyes) with endophthalmitis associated with liver abscess who underwent surgery at Shengjing Hospital were retrospectively analyzed. Furthermore, we evaluated the final visual outcomes in the patients to determine the efficacy of surgery.

Results

Fifteen patients (18 eyes) underwent intravitreal injection followed by vitrectomy after admission. One patient (1 eye) only underwent intravitreal injection. Of the 16 patients, 3 patients (3 eyes) had recurrent intraocular inflammation and eventually underwent evisceration. Systemic antibiotics were administered for all patients based on the results of vitreous humor culture, blood culture, and antibiotic susceptibility tests. Outpatient follow-ups were performed until the patients were stable (6 months). Of the 19 eyes, 1 eye (5%) had visual acuity restored to 20/200, 6 eyes (31%) had visual acuity restored to counting fingers (CF), 2 eyes (11%) had visual acuity restored to hand motion (HM), 4 eyes (22%) showed only light perception (LP), and the remaining 6 eyes (31%) showed no light perception (NLP). Drug susceptibility tests suggested that the carbapenems exhibited significant effects in the inflammatory reaction.

Conclusion

Endogenous endophthalmitis caused by liver abscess is a very serious condition, and the final visual outcome is poor. Timely surgical intervention combined with antibiotic treatment is essential, and the primary disease must be treated to control disease progression at the earliest.