Experimental Klebsiella-induced endophthalmitis in the rabbit

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.

CONCOMITANT PYOGENIC LIVER AND INTRAOCULAR ABSCESSES IN KLEBSIELLA ENDOGENOUS ENDOPHTHALMITIS: CASE REPORT AND REVIEW OF LITERATURE

PURPOSE

To describe a rare presentation of Klebsiella pneumoniae endogenous endophthalmitis with concurrent intraocular and liver abscesses.

METHODS

Case Report.

RESULTS

A middle-aged man presented with a red and painful eye with a preceding febrile gastrointestinal illness. Examination and work-up revealed concomitant intraocular and liver abscesses that were treated by pars plana vitrectomy, drainage of subretinal abscess, inpatient admission, and systemic antibiotics. The patient ultimately underwent enucleation of the eye because of persistent pain and poor visual prognosis.

CONCLUSION

Klebsiella pneumoniae endogenous endophthalmitis is a rare and potentially devastating disease that requires high clinical suspicion and early diagnosis. Practitioners should consider systemic etiologies and communicate guarded prognoses in this serious systemic disease.

Characteristics of Computed Tomography for Identifying Patients at High Risk of Endogenous Endophthalmitis Due to Klebsiella pneumoniae-Related Pyogenic Liver Abscess

Endogenous endophthalmitis (EE) associated with Klebsiella pneumoniae (K. pneumoniae)-related pyogenic liver abscess (PLA) is one of the fatal complications of PLA and leads to loss of vision. Early diagnosis and treatment are important to save the patient’s vision. We investigated the characteristics of computed tomography (CT) in EE associated with K. pneumoniae-related PLA for the identification of the predictors of EE, in order to facilitate early diagnosis. A total of 274 patients diagnosed with K. pneumoniae-related PLA, including 15 patients with EE, were identified between January 2005 and December 2019. The clinical (age, gender, and underlying disease) and radiologic (the location, size, and number of abscesses) features were reviewed. In addition, the involvement of the adjacent vessels, such as the hepatic vein and portal vein, was carefully reviewed. A comparative analysis was performed between the EE and non-EE groups. Uni- and multivariate logistic regression analyses were used to identify the predictors of EE. Diabetes mellitus (DM), the involvement of the left or both hepatic lobes, and the adjacent vessels on the CT were significantly more frequent than those in the non-EE group (p < 0.05 in all), and they were the significant predictors of EE in the logistic regression analyses. In patients with K. pneumoniae-related PLA, the CT findings, such as the locations of the abscess (i.e., left or both lobes) and the involvement of the adjacent vessels, should be considered in addition to the ocular symptoms for an early diagnosis of EE.

Report of Four Cases of Endogenous Klebsiella Pneumoniae Endophthalmitis Originated from Liver Abscess with Eye Complaints as the Initial Presentations

PURPOSE

To report four cases of endogenous endophthalmitis (EE) secondary to Klebsiella pneumoniae liver abscess, and discuss their clinic features and outcomes.

METHODS

Clinical data were collected by reviewing the medical records of four patients diagnosed with endogenous Klebsiella Pneumoniae endophthalmitis (EKPE) secondary to liver abscess.

RESULTS

Four patients were diagnosed with EE. Two males and two females, with ages ranging from 33 to 63 years old. All patients presented with ocular symptoms initially. Liver abscesses were diagnosed during hospitalization. All cases were caused by Klebsiella Pneumoniae confirmed by blood or tissue cultures. All patients were treated with intravitreal antibiotic injection, and two of the patients had vitrectomy. At the end, all affected eyes underwent evisceration. One patient died of septic shock with multiple organ failures.

CONCLUSION

EE secondary to liver abscess with metastatic spread is a severe sight-threatening condition. The delayed discovery of liver abscess may hinder the diagnosis and treatment of the disease, which may be related to poor prognosis.

Effect of intravitreal ceftazidime injection on endogenous klebsiella pneumoniae endophthalmitis, a single center case series

To report long-term outcomes of intravitreal ceftazidime injection in patients with endogenous Klebsiella pneumoniae endophthalmitis (EKPE).This was a retrospective observational case study, including 7 eyes from 6 patients with EKPE. The medical records from January 2010 to December 2018 were reviewed.Diagnosis of EKPE was made based on the finding of endophthalmitis with concurrent systemic infection and positive blood culture result. All patients received tap and intravitreal ceftazidime injection base on the results of antibiotics sensitivity test. Visual acuity ranged from no light perception to 20/60 at initial visit, and the final visual acuity was 20/20. Two eyes underwent evisceration after intravitreal injection.Intravitreal ceftazidime injection showed favorable results in patients with EKPE.

Prognostic Factors and Visual Outcomes of Pyogenic Liver Abscess-Related Endogenous Klebsiella pneumoniae Endophthalmitis: A 20-year retrospective review

Endogenous K. pneumoniae endophthalmitis (EKE) has a higher incidence among East Asians, and the most common infectious source of EKE is pyogenic liver abscess (PLA). We investigate the risk factors for poor visual outcomes in patients with PLA-related EKE. The retrospective medical records of 104 patients (120 eyes) diagnosed with PLA-related EKE between 1996 and 2015. In univariate logistic regression analysis, the risk factors for poor visual outcomes were initial visual acuity (VA) worse than counting fingers (CF) (p < 0.001), eye pain (p = 0.013), hypopyon (p = 0.003), ocular hypertension (p = 0.003), positive intraocular fluids cultures (p < 0.001), subretinal abscess (p = 0.025), unilateral involvement (p = 0.017), delayed ophthalmologic visit (p = 0.022), initially presented with ocular symptoms ahead of systemic symptoms (p < 0.001), and corneal edema (p < 0.001). Intravitreal dexamethasone reduced the requirement of enucleation or evisceration (p = 0.01). The multivariate logistic regression revealed that poor initial VA worse than CF (p = 0.004) and initially presented with ocular symptoms ahead of systemic symptoms (p = 0.007) were the significant independent factors for poor visual outcomes. Early diagnosis and prompt treatment may salvage useful vision in some eyes.

Endophthalmitis caused by Klebsiella species

PURPOSE

To report the clinical presentation, antibiotic sensitivities, treatment strategies, and visual outcomes associated with endophthalmitis caused by Klebsiella species.

METHODS

A noncomparative consecutive case series. Microbiology database records were retrospectively reviewed for all patients with endophthalmitis caused by Klebsiella species from 1990 to 2012 at a large university referral center. The corresponding clinical records were then reviewed to evaluate the endophthalmitis clinical features and treatment outcomes.

RESULTS

Seven patients were identified. Clinical settings included endogenous (n = 3), posttraumatic (n = 2), trabeculectomy bleb-associated (n = 1), and postpenetrating keratoplasty (n = 1). Five patients presented with hypopyon. Presenting visual acuity ranged from 20/60 to light perception in nonendogenous cases and 1/200 to light perception in endogenous cases. Klebsiella was sensitive to aminoglycosides, third-generation cephalosporins, and second- and third-generation fluoroquinolones in all cases. Initial treatment strategies were vitreous tap and injection (n = 4), pars plana vitrectomy with intravitreal antibiotics (n = 2), and anterior chamber tap and injection (n = 1). All three endogenous cases later underwent enucleation or evisceration. In nonendogenous cases, the final visual acuity was 20/70 or better in all 4 patients.

CONCLUSION

Endophthalmitis caused by Klebsiella species is associated with poor visual outcomes. Endogenous cases had high rates of enucleation or evisceration.

Risk factors for endogenous endophthalmitis secondary to klebsiella pneumoniae liver abscess: 20-year experience in Southern Taiwan

PURPOSE

To identify the risk factors for endogenous endophthalmitis secondary to Klebsiella pneumoniae liver abscess.

METHODS

We conducted a retrospective review of medical records of 602 patients admitted with K. pneumoniae liver abscess from January 1991 to November 2009. Variables included age, sex, history, month of onset, systemic condition, initial and final visual acuities, slit-lamp biomicroscopy, intraocular pressure, fundus, course and treatment.

RESULTS

Endophthalmitis was identified in 42 patients (53 eyes). Nineteen eyes (35.8%) had final vision of counting fingers or better. Diabetes was significantly associated with the development of endophthalmitis (P = 0.003) and poor visual outcome (P = 0.019). Poor initial vision (worse than counting fingers) was also significantly related to the poor visual outcome of endophthalmitis (P < 0.001). Subgroup analysis of 9 vitrectomy cases showed that progressive anterior chamber reaction might be related to poor visual outcome. Moreover, patients whose disease onset was in winter were slightly more likely to develop endophthalmitis (P = 0.088).

CONCLUSION

Although the prognosis of endogenous K. pneumoniae endophthalmitis is generally poor, some eyes might be saved if treated early enough. Diabetes is a significant risk factor for the development of endogenous endophthalmitis and poor visual outcome in patients with K. pneumoniae liver abscess. Early vitrectomy might be considered in patients whose anterior chamber inflammation did not respond well to intravitreal antibiotics.

Endogenous Klebsiella endophthalmitis associated with Klebsiella pneumoniae pneumonia

PURPOSE

To investigate the management, bacterial strains, antibiotic sensitivities, and visual outcomes in patients with Klebsiella pneumoniae pneumonia and endogenous Klebsiella endophthalmitis.

METHODS

Data were collected for treatments, antibiotic sensitivity patterns, and final visual outcomes.

RESULTS

The study included 10 eyes of 9 patients with a median age of 42 years (range, 0-86 years). Diabetes mellitus was the most common comorbid risk factor (n = 5, 56%). Nine eyes (90%) were treated with intravitreal antibiotics, and one with pars plana vitrectomy and intravitreal antibiotics. One eye achieved a favorable visual acuity of 20/20; however, 6 eyes developed vision of no light perception, including 2 of evisceration. Two nosocomial K. pneumoniae isolates were extended-spectrum-beta-lactamase-producing strains, which demonstrated the resistance to amikacin and ceftazidime.

CONCLUSIONS

Ophthalmologists and physicians should be aware of Klebsiella pneumonia as a possible cause of endogenous endophthalmitis, and endogenous Klebsiella endophthalmitis usually causes poor visual outcomes.

Hypermucoviscosity as a virulence factor in experimental Klebsiella pneumoniae endophthalmitis

PURPOSE

Klebsiella pneumoniae is a common cause of endogenous bacterial endophthalmitis, a disease that frequently results in a poor visual outcome. Hypermucoviscosity has been identified as a virulence factor among clinical bacteremia isolates of K. pneumoniae. In this study, an experimental murine model of K. pneumoniae endophthalmitis was established, and the role of hypermucoviscosity in its pathogenesis was analyzed.

METHODS

C57BL/6J mice were intravitreously injected with 100 CFU of hypermucoviscous (HMV+) or nonhypermucoviscous (HMV-) K. pneumoniae. Intraocular bacterial growth, retinal function, gross pathology, and inflammatory responses were monitored every 3 hours until the eyes lost significant (>90%) retinal function, or the infection appeared to clear.

RESULTS

The HMV+ strain grew logarithmically in eyes until approximately 15 hours postinfection (PI), reaching a stationary phase of growth at approximately 8.0 log(10) CFU/eye. The HMV- strain grew logarithmically to approximately 7.6 log(10) by 18 hours, but bacterial count declined to approximately 6.4 log(10) CFU/eye by 21 hours PI. Eyes infected with the HMV+ strain retained approximately 35% a-wave and <10% b-wave function by 18 hours PI. These eyes also had a cumulative clinical score of 14+ by 18 hours and underwent phthisis between 21 and 24 hours. Eyes infected with the HMV- strain had a cumulative clinical score of <6 and retained >60% a-wave and >50% b-wave function throughout 21 hours. Five of 7 eyes had <100 CFU HMV- K. pneumoniae at 27 hours PI.

CONCLUSIONS

The findings demonstrate the site-threatening consequences of K. pneumoniae endophthalmitis and the importance of the hypermucoviscosity phenotype in the pathogenesis of experimental K. pneumoniae endophthalmitis.

Endogenous Klebsiella endophthalmitis associated with pyogenic liver abscess

OBJECTIVE

To study risk factors, clinical features, treatment, and visual outcomes in patients with endogenous Klebsiella pneumoniae endophthalmitis (EKE) associated with K. pneumoniae-induced pyogenic liver abscess, and to investigate contributing factors in successfully treated cases.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Review of medical records of 22 consecutive patients with EKE and pyogenic liver abscess.

METHODS

The affected eyes of 22 consecutive patients (n = 27) with EKE, who presented to our ophthalmic service during a recent 8-year period, were studied retrospectively.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (VA) at end of follow up.

RESULTS

Diabetes mellitus was the most common comorbid risk factor (n = 15 [68%]). Five patients (23%) had bilateral eye involvement. On initial presentation, characteristic pupillary hypopyon was observed in 12 eyes. Diagnosis was confirmed by blood culture in 8 patients, culture of liver aspirate in 17 patients, and vitreous culture in 11 patients. Other associated septic metastatic lesions included pulmonary abscess or emboli in 6 cases, brain abscess or meningitis in 3 cases, and prostate and kidney abscesses in 1 case. Despite aggressive intravenous and intravitreal antibiotic therapy, final VA of light perception or worse affected 24 eyes (89%), of which 11 (41%) were eventually eviscerated or enucleated. Successful treatment with retained useful vision better than 6/60 was achieved in 3 eyes, of which 2 received early intravitreal corticosteroid injections. However, the other remaining eye had a focal subretinal abscess.

CONCLUSION

Physicians should be alert to the development of EKE when patients with diabetes along with K. pneumoniae-induced pyogenic liver abscess complain of ocular symptoms. In the majority of patients with EKE associated with pyogenic liver abscess, visual outcome is generally poor despite aggressive antibiotic therapy. Early diagnosis and prompt intervention with intravitreal antibiotics within 48 hours may salvage useful vision in some patients with EKE.

Fulminant endogenous Klebsiella pneumoniae endophthalmitis: imaging findings

Endogenous endophthalmitis is a rare but serious complication of Klebsiella pneumoniae infection that has been predominantly reported to occur in diabetic patients of East Asian origin with K. pneumoniae liver abscesses. The clinical symptoms and signs of endogenous endophthalmitis are nonspecific and may mimic other causes of an acute non-traumatic eye. Permanent visual loss and blindness are common sequelae because of delayed diagnosis and treatment. Computed tomography and magnetic resonance imaging can help to differentiate endophthalmitis from other causes of acute non-traumatic eye when the clinical findings are equivocal. Fluid attenuated inversion recovery and diffusion-weighted imaging with apparent diffusion coefficient map are superior to T2-weighted and gadolinium-enhanced T1-weighted sequences in demonstrating intra-ocular abscesses.

Endogenous bacterial endophthalmitis: a 17-year prospective series and review of 267 reported cases

Endogenous bacterial endophthalmitis is a rare but serious condition that occurs when bacteria cross the blood-ocular barrier and multiply within the eye. We provide an overview of endogenous bacterial endophthalmitis by reviewing 267 reported cases and integrating this with our experience of an additional 19 cases. The majority of patients with endogenous bacterial endophthalmitis are initially misdiagnosed and many have an underlying disease known to predispose to infection. This condition is often previously undiagnosed. Blood cultures are the most frequent means of establishing the diagnosis. The most common Gram positive organisms are Staphylococcus aureus, group B streptococci, Streptococcus pneumoniae,and Listeria monocytogenes. The most common Gram negative organisms are Klebsiella spp., Escherichia coli, Pseudomonas aeruginosa, and Neisseria meningitidis. Gram negative organisms are responsible for the majority of cases reported from East Asian hospitals, but Gram positive organisms are more common in North America and Europe. The visual outcome is poor with most cases leading to blindness in the affected eye. Many patients have extraocular foci of infection, with an associated mortality rate of 5%. The outcome of endogenous bacterial endophthalmitis has not improved in 55 years and clinicians need to have a high level of awareness of this commonly misdiagnosed condition.

An antimicrobial effect associated with rabbit primary aqueous humour

Viability curves were recorded for a variety of bacteria suspended in rabbit primary aqueous humour. Controls included neat rabbit serum, dilute rabbit serum (1/50), dilute heat treated fetal bovine serum (1/50), and balanced salt solution. Rabbit aqueous humour was bactericidal in vitro for Staphylococcus aureus and Pseudomonas aeruginosa. Micrococcus spp, Streptococcus pneumoniae and Escherichia coli were not affected. The factor mediating the bactericidal effect survives filtration (0.2 micron porosity) and freezing in liquid nitrogen (-196 degrees C) but is labile when stored in air at temperatures of 4 degrees C, 25 degrees C, and 37 degrees C for 1 hour. The bactericidal effect was stable when aqueous humour was stored in an atmosphere of 5% CO2 at 37 degrees C for 3 hours. The antibacterial component in rabbit aqueous humour has yet to be identified.

Infective endophthalmitis following vitreoretinal surgery

Eleven cases of endophthalmitis occurring after vitreoretinal surgery are described. At Moorfields Hospital, London, from 1986 to 1990 the incidence of endophthalmitis after explant surgery with or without drain was 0.19% and after vitrectomy was 0.15%. We conclude that the parity may be due to the intraocular instrumentation of most conventional retinal detachment repair procedures. The best indicator of poor prognosis was speed of onset of symptoms, those with rapid evolution having the worst outcome; 2 of these cases were enucleated. Those presenting at 2-3 days had the best outcome, consistent with infection due to a less virulent organism. Delays in diagnosis were in part due to the posterior location of signs of infection. Potential risk factors amenable to prophylactic strategy were identified in 10 of the 11 patients. Supplementary prophylaxis using ciprofloxacin or imipenem is proposed for cases with an identifiable risk factor. After systemic administration these antibiotics achieve vitreous levels that exceed the MIC90 of the commonest causative pathogens.

Proton magnetic resonance spectroscopy of vitreal changes in experimental streptococcal endophthalmitis

We used magnetic resonance spectroscopy to examine endophthalmitis in rabbits inoculated with a virulent strain of Streptococcus pneumoniae. On different days after infection, the animals were sacrificed and the vitreous isolated and examined with water-suppressed proton magnetic resonance spectroscopy. A broad resonance corresponding to the methyl envelope of lipoprotein lipids appeared 2 days after infection and persisted until the eyes developed phthisis (around 10 days postinfection). This resonance was absent in the control eye and the bacterial culture; it could be used as the marker of breakdown of blood-vitreous barrier and onset of endophthalmitis-induced changes.

Contribution of the pAD1-encoded cytolysin to the severity of experimental Enterococcus faecalis endophthalmitis

The contribution of the pAD1-encoded cytolysin to Enterococcus faecalis virulence in an experimental endophthalmitis model was studied by using isogenic strains differing only in the location of transposon Tn917. The course of experimental endophthalmitis in New Zealand White rabbits was evaluated by postoperative reduction in retinal neuroresponsiveness, thin-section histopathology, and transmission electron microscopy. Infections caused by cytolytic E. faecalis resulted in 99% loss of retinal function at postoperative day 3, while isogenic, noncytolytic strains produced reductions of only 74.2%. Light microscopy revealed near-total destruction of retinal architecture at 24 h postinfection with cytolytic E. faecalis, while noncytolytic strains produced few or no destructive changes. Transmission electron microscopy revealed tissue destruction in retinal layers as early as 6 h postinfection with cytolytic E. faecalis. In vivo and in vitro growth rates of cytolytic and noncytolytic E. faecalis showed similar kinetics. These data demonstrate the contribution of the pAD1-encoded cytolysin to both the course and the severity of experimental E. faecalis endophthalmitis.

A search for gram-negative enteric micro-organisms in acute anterior uveitis: association of klebsiella with recent onset of disease, HLA-B27, and B7 CREG

Faecal samples obtained from patients with acute anterior uveitis (AAU) and healthy controls unconnected with hospitals were examined for the presence of Gram-negative micro-organisms reported to be associated with AAU. There was an increased recovery of Klebsiella spp. from AAU patients seen in the first and in the second week after onset of symptoms when compared with patients presenting three to four weeks after onset of symptoms (p less than 0.025 and p less than 0.05 respectively) or with healthy control subjects (p less than 0.005 and p less than 0.05 respectively). By the third to fourth week there was no difference in klebsiella recovery between AAU patients and controls. The increased faecal recovery of klebsiella in the first two weeks was predominantly in HLA-B27 positive patients or patients possessing antigens which cross-react with B27, namely, HLA-B7 CREG. The patients with faecal cultures positive for klebsiella had a higher mean ESR than patients with negative faecal cultures (p less than 0.05). Although there was an increase in recovery of faecal klebsiella from AAU patients with spondylarthritis when compared with AAU patients without arthritis, the difference was not statistically significant. These results suggest that some klebsiella micro-organisms may play a role in the aetiopathogenesis of AAU associated with HLA-B27 or HLA-B7 CREG.