High-resolution genotyping of Pseudomonas aeruginosa strains linked to acute post cataract surgery endophthalmitis outbreaks in India

Conjunctival sac bacterial culture of patients using levofloxacin eye drops before cataract surgery: a real-world, retrospective study

Background

The use of antibiotics preoperatively is effective to decrease the incidence of ocular bacterial infections but may lead to high resistance rate, especially on patients with multi-risk clinical factors. This study systematically analyzed real-world data (RWD) of patients to reveal the association between clinical factors and conjunctival sac bacterial load and offer prophylaxis suggestions.

Methods

We retrieved RWD of patients using levofloxacin eye drops (5 mL: 24.4 mg, 4 times a day for 3 days) preoperatively. Retrieved data included information on the conjunctival sac bacterial culture, sex, presence of hypertension and diabetes mellitus (DM), and history of hospital-based surgeries. Data was analyzed using SPSS 24.0.

Results

RWD of 15,415 cases (patients) were retrieved. Among these patients, 5,866 (38.1%) were males and 9,549 (61.9%) females. 5,960 (38.7%) patients had a history of hypertension, and 3,493 (22.7%) patients had a history of DM. 7,555 (49.0%) patients had a history of hospital-based operations. There were 274 (1.8%) positive bacterial cultures. Male patients with hypertension and DM may be at increased risk of having positive bacterial cultures (P < 0.05). Staphylococcus epidermidis (n = 56, 20.4%), Kocuria rosea (n = 37, 13.5%), and Micrococcus luteus (n = 32, 11.7%) were the top 3 isolated strains. Most bacterial strains were resistant to various antibiotics except rifampin, and 82.5% (33 of 40 isolates) of Staphylococcus epidermidis isolates had multidrug antibiotic resistance. Numbers of culture-positive Staphylococcus epidermidis isolates in the male group and non-DM group were greater than those in the female and DM groups, respectively. Micrococcus luteus (n = 11, 8.8%) was found less frequently in non-hypertension group than in hypertension group.

Conclusion

Sex (Male) and the presence of hypertension and DM are risk factors for greater conjunctival sac bacterial loads. We offer a prophylactic suggestion based on the combined use of levofloxacin and rifampin. However, this approach may aggravate risk of multidrug resistance.

All India Ophthalmological Society (AIOS) Task Force guidelines to prevent intraocular infections and cluster outbreaks after cataract surgery

Infectious endophthalmitis is a serious and vision-threatening complication of commonly performed intraocular surgeries such as cataract surgery. The occurrence of endophthalmitis can result in severe damage to the uveal and other ocular tissues even among patients undergoing an uncomplicated surgical procedure. If the infections result from common factors such as surgical supplies, operative or operation theater-related risks, there can be a cluster outbreak of toxic anterior segment syndrome (TASS) or infectious endophthalmitis, leading to several patients having an undesirable outcome. Since prevention of intraocular infections is of paramount importance to ophthalmic surgeons, the All India Ophthalmological Society (AIOS) has taken the lead in the formation of a National Task Force to help ophthalmic surgeons apply certain universal precautions in their clinical practice. The Task Force has prepared a handy checklist and evidence-based guidelines to minimize the risk of infectious endophthalmitis following cataract surgery.

Clinical features of endophthalmitis clusters after cataract surgery and practical recommendations to mitigate risk: systematic review

Intraocular transmission of exogenous pathogens in cataract surgery can lead to endophthalmitis. This review evaluates the features of endophthalmitis clusters secondary to pathogen transmission in cataract surgery. Articles reporting on pathogen transmission in cataract surgery were identified via searches of Ovid MEDLINE, EMBASE, and Cochrane CENTRAL, and a total of 268 eyes from 24 studies were included. The most common source of infectious transmission was attributed to a contaminated intraocular solution (ie, irrigation solution, viscoelastic, or diluted antibiotic; n = 10). Visual acuity at presentation with infectious features was 1.89 logMAR (range: 1.35 to 2.58; ∼counting fingers) and 1.33 logMAR (range: 0.04 to 3.00; Snellen: ∼20/430) at last follow-up. Patients with diabetes had worse outcomes compared with patients without diabetes. The most frequently isolated pathogen from the infectious sources was Pseudomonas sp. (50.0%). This review highlights the various routes of pathogen transmission during cataract surgery and summarizes recommendations for the detection, prevention, and management of endophthalmitis clusters.

Clinical profile, visual outcome and root cause analysis of post-operative cluster endophthalmitis due to Burkholderia cepacia complex

Purpose:

To present varied clinical presentations, surveillance reports, and final visual outcomes of a rare outbreak of cluster endophthalmitis caused by gram-negative, opportunistic bacilli, Burkholderia cepacia complex (Bcc).

Methods:

Details of five patients who developed postoperative cluster endophthalmitis were collected. For each patient, an undiluted vitreous sample was collected during vitreous tap. Bacterial culture from the vitreous sample in each case had grown Bcc. Surveillance investigations for root cause analysis (RCA) were performed in the operating room (OR), admission, and day-care wards to localize the source.

Results:

Four patients had undergone phacoemulsification surgery, and one patient had undergone penetrating keratoplasty. Each patient received an initial dose of empiric intravitreal ceftazidime and vancomycin. The organism isolated in each case was sensitive to ceftazidime, cotrimoxazole, and meropenem and resistant to other antibiotics. Core vitrectomy was done after 48–60 hours in four patients along with intravitreal imipenem injection. One patient did not provide consent for core vitrectomy and subsequently developed phthisis bulbi. Three patients had subsequent recurrences. Two patients had a final BCVA of 20/60, two had BCVA better than 20/200, while one patient had no perception of light. None of the surveillance samples from the OR complex could isolate Burkholderia.

Conclusion:

Extensive OR surveillance should be done to identify the potential source of infection. However, the source may not be identifiable in few instances like in our case. Longer follow-up is recommended in cases of Bcc endophthalmitis due to the persistent nature of the infection.

Post-cataract surgery cluster endophthalmitis due to multidrug-resistant Pseudomonas aeruginosa: A retrospective cohort study of six clusters

Purpose

To analyze clinical presentations, antibiotic susceptibility, and visual outcomes in six clusters of post cataract surgery endophthalmitis caused due to multidrug-resistant Pseudomonas aeruginosa (MDR-PA). This was a hospital-based retrospective cohort study.

Methods

Our study comprised sixty-two patients from six nonconsecutive clusters of post cataract surgery endophthalmitis caused by MDR-PA referred to our tertiary eye care institute. Demographic details, best-corrected visual acuity (BCVA), clinical features, microbiological findings, and patient management were reviewed.

Results

The interval between onset of symptoms and presentation ranged from 1 to 7 (mean: 4.61 and median: 5) days. The presenting BCVA was no light perception in 17 (27.4%) eyes, light perception in 35 (56.4%) eyes, and hand movement or better in 10 (16.1%) eyes. All patients had hypopyon and vitreous exudates. Corneal infiltrates were noted in 40 (64.5%) eyes. Panophthalmitis was diagnosed in 20 (32.2%) eyes. The surgical intervention included intraocular antibiotics (IOAB) in 8 (12.9%) eyes, pars plana vitrectomy with IOAB in 26 (41.9%) eyes, and evisceration in 23 (37.09%) eyes. At 6 weeks, BCVA of 20/200 or better was achieved in 9 (14.5%) eyes. Pseudomonas aeruginosa was least resistant to colistin (8.3%), piperacillin (31.8%), and imipenem (36.1%). Ceftriaxone and ceftazidime resistance was seen in 80.5% and 70% isolates, respectively.

Conclusion

Cluster endophthalmitis due to MDR-PA has poor visual outcomes with high rates of evisceration. In the setting of cluster endophthalmitis where MDR-PA is the most common etiology, piperacillin or imipenem can be the first drug of choice for empirical intravitreal injection for gram-negative coverage while awaiting the drug susceptibility report.

Outbreak of Multidrug-resistant Pseudomonas Aeruginosa Endophthalmitis Due to Contaminated Trypan Blue Solution

Purpose

To report the investigation of an outbreak of multidrug-resistant (MDR) Pseudomonas aeruginosa endophthalmitis in 13 patients after cataract surgery and to emphasize on the importance of clinical profile, risk factors, and treatment outcomes

Methods

This was a hospital-based, retrospective case study with 13 consecutive patients who had man- ual small-incision cataract surgery with intraocular lens (IOL) implantation and developed acute postoperative Pseudomonas aeruginosa endophthalmitis. The anterior chamber taps, vitreous aspirates, and environ- mental surveillance specimens were inoculated for culturing. Antibiotic susceptibility testing was performed using the agar diffusion method. Pulsed-field gel electrophoresis (PFGE) was used to determine the relation- ship between bacterial isolates recovered from study patients and contaminated surveillance samples.

Results

Pseudomonas aeruginosa was isolated from all 13 eyes with acute postoperative endophthalmitis and the trypan blue solutions used during surgery. Sensitivity tests revealed that all isolates had an identical resistance to multiple drugs and were only susceptible to imipenem. Genomic DNA typing of Pseudomonas aeruginosa isolates recovered from patients and trypan blue solutions showed an identical banding pattern on the PFGE. Despite the prompt use of intravitreal antibiotics and early vitrectomy with IOL explantation in some patients, the outcome was poor in about 50% of patients.

Conclusion

Positive microbiology and genomic DNA typing results proved that the contaminated trypan blue solutions were the source of infection in this outbreak. Postoperative endophthalmitis caused by Pseudomonas aeruginosa is often associated with a poor visual prognosis despite prompt treatment with intravitreal antibiotics.

Redefining evidence in the management of acute post-cataract surgery endophthalmitis in India - The 2014 Adenwalla Oration, All India Ophthalmological Society

The current evidence of postoperative endophthalmitis management in three important components of care-infection control, inflammation control, and prevention was reviewed, and their current relevance and application in an Indian context were evaluated. The publications from India indicated that Gram-negative bacterial and filamentous fungal infections are relatively higher. There are increasing instances of resistance to ceftazidime by Gram-negative microorganisms. Intravitreal dexamethasone limits inflammation in bacterial endophthalmitis when given together with the intravitreal antibiotics. Intracameral antibiotic could reduce postcataract surgery infection at least in less rigorous surgical environment. Systematic collection of data and periodic evaluation of the current practice against the new evidence are necessary to prevent or treat postcataract surgery endophthalmitis.

A literature review and update on the incidence and microbiology spectrum of postcataract surgery endophthalmitis over past two decades in India

Purpose:

The purpose of this study was to review the incidence and microbiology of acute postcataract surgery endophthalmitis in India.

Methods:

Systematic review of English-language PubMed referenced articles on endophthalmitis in India published in the past 21 years (January 1992–December 2012), and retrospective chart review of 2 major eye care facilities in India in the past 5 years (January 2010–December 2014) were done. The incidence data were collected from articles that described “in-house” endophthalmitis and the microbiology data were collected from all articles. Both incidence and microbiological data of endophthalmitis were collected from two large eye care facilities. Case reports were excluded, except for the articles on cluster infection.

Results:

Six of 99 published articles reported the incidence of “in-house” acute postcataract surgery endophthalmitis, 8 articles reported the microbiology spectrum, and 11 articles described cluster infection. The clinical endophthalmitis incidence was between 0.04% and 0.15%. In two large eye care facilities, the clinical endophthalmitis incidence was 0.08% and 0.16%; the culture proven endophthalmitis was 0.02% and 0.08%. Gram-positive cocci (44%-64.8%; commonly, Staphylococcus species), and Gram-negative bacilli (26.2%–43%; commonly Pseudomonas species) were common bacteria in south India. Fungi (16.7%-70%; commonly Aspergillus flavus) were the common organisms in north India. Pseudomonas aeruginosa (73.3%) was the major organism in cluster infections.

Conclusions:

The incidence of postcataract surgery clinical endophthalmitis in India is nearly similar to the world literature. There is a regional difference in microbiological spectrum. A registry with regular and uniform national reporting will help formulate region specific management guidelines.

ENDOPHTHALMITIS CAUSED BY PSEUDOMONAS AERUGINOSA: Clinical Features, Antibiotic Susceptibilities, and Treatment Outcomes

PURPOSE

To report the clinical features, antibiotic susceptibilities, and visual outcomes associated with endophthalmitis caused by Pseudomonas aeruginosa.

METHODS

A consecutive case series. Microbiology database records were retrospectively reviewed for all patients with endophthalmitis caused by P. aeruginosa from January 1, 2002, to December 31, 2012, at a large university referral center. The corresponding clinical records were then reviewed to evaluate the endophthalmitis clinical features and treatment outcomes.

RESULTS

In the 12 patients identified, clinical settings included postcataract surgery (n = 4), postpenetrating keratoplasty (n = 3), endogenous source (n = 2), post-pars plana vitrectomy (n = 1), trabeculectomy bleb-associated setting (n = 1), and glaucoma drainage implant-associated setting (n = 1). All patients presented with hypopyon. Presenting visual acuity was hand motions or worse in all cases. All isolates were susceptible to ceftazidime and levofloxacin. When comparing isolates in this study with isolates from a previous study (1987 to 2001), the minimal inhibitory concentration required to inhibit 90% of isolates (MIC 90, in micrograms per milliliter) remained the same for ceftazidime (8), ciprofloxacin (0.5), imipenem (4), tobramycin (0.5), and amikacin (4). Initial treatment strategies were vitreous tap and injection (n = 9) and pars plana vitrectomy with intravitreal antibiotics (n = 3). Final visual acuity was light perception or worse in 11 of the 12 patients (92%). Five patients underwent enucleation (42%).

CONCLUSION

All isolates were susceptible to ceftazidime and levofloxacin, and all MIC 90s for isolates in the current period compared with isolates from 1987 to 2001 remained identical. Despite early and appropriate treatment, outcomes were generally poor with a high rate of enucleation.

An outbreak of acute post-cataract surgery Pseudomonas sp. endophthalmitis caused by contaminated hydrophilic intraocular lens solution

OBJECTIVE

To report the investigation for the source of infection and the clinical course and treatment response of 11 cases of acute post-cataract surgery endophthalmitis that developed during an outbreak.

DESIGN

Retrospective, consecutive, interventional case series.

PARTICIPANTS

Eleven patients who developed acute postoperative endophthalmitis after an uneventful cataract surgery with intraocular lens implantation from September 6 to 29, 2010, at a tertiary eye care center in South India.

METHODS

Aqueous aspirates, vitreous aspirates, and environmental surveillance specimens were sampled. All specimens were subjected to smear and culture. Positive cultures were subjected to antibiotic susceptibility. Genotypic diversity was determined by polymerase chain reaction (PCR) with enterobacterial repetitive intergenic consensus (ERIC) primers of each strain and was used to establish the clonal relationship between clinical and environmental isolates. The clinical patterns were analyzed.

MAIN OUTCOME MEASURES

Positive microbiology, molecular diagnostic similarity among the culture positive endophthalmitis cases, and surveillance specimens.

RESULTS

Aqueous and vitreous samples showed gram-negative bacilli in the smears of 8 of 11 eyes, and cultures grew Pseudomonas aeruginosa in 5 of 11 eyes. Among the samples from various surveillance specimens cultured, only the hydrophilic acrylic intraocular lenses and their solution grew P. aeruginosa, with antibiotic susceptibility pattern identical to the clinical isolates. The isolates from the patients and the intraocular lens solution revealed matching patterns similar to an American Type Culture Collection (ATCC) strain of P. aeruginosa on ERIC-PCR. The intraocular lenses of the same make were discontinued at our hospital, and the endophthalmitis did not recur. The final visual acuity improved to ≥ 20/50 in 8 of 11 patients (72.7%). One patient developed retinal detachment, but was treated successfully, and 2 other patients progressed to phthisis bulbi.

CONCLUSIONS

Positive microbiology and the ERIC-PCR results proved that contamination of hydrophilic intraocular lenses and the preservative solution was the source of infection in this outbreak. Early detection and a planned approach during the outbreak helped us to achieve good visual and anatomic outcomes, even though the offending organism was identified as P. aeruginosa.

Genotypic Characterization of Staphylococcus aureus Obtained from Humans and Bovine Mastitis Samples in India

AIM AND BACKGROUND

Staphylococcus aureus is a major human pathogen that also causes important infections in cattle and sheep. The present study aimed to test genetic diversity among strains of S. aureus isolated from cattle (n=34) and humans (n=22) by DNA typing.

MATERIALS AND METHODS

Fluorescent amplified fragment length polymorphism (FAFLP) is the genotyping tool used in the study. The presence of the mecA and Panton-Valentine leukocidin (PVL) genes among these strain groups was also checked.

RESULTS

A dendrogram deduced from FAFLP showed that all the strains clustered into 10 groups (A-J) with a relative genetic divergence of less than 8%. Sixty-seven percent of the isolates from bovine sources clustered together in two clades (A and H), while another major cluster with 13 isolates (59%) (Cluster G) had all strains from a human host. The remaining strains from both the hosts clustered independently into smaller clusters with the exception of two strains of human origin, which clustered along with a bovine cluster. Thirteen strains belonging to cluster G were highly clonal. About 77% of strains obtained from human infections were methicillin-resistant S. aureus (MRSA), whereas only 29% of strains from bovine origin were MRSA. Only three strains from human origin showed PVL positive, while no strain from cattle had PVL genes. The complete absence of PVL genes in all the bovine strains in the study appears to be significant.

CONCLUSIONS

FAFLP can be successfully applied to assess the genetic relationship of S. aureus isolates from different hosts. The study also provided the valuable epidemiological data on S. aureus from bovine sources in India, which is lacking.

Pseudomonas aeruginosa outbreak linked to mineral water bottles in a neonatal intensive care unit: fast typing by use of high-resolution melting analysis of a variable-number tandem-repeat locus

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial infections in intensive care units. Determining a system of typing that is discriminatory is essential for epidemiological surveillance of P. aeruginosa. We developed a method for the typing of Pseudomonas aeruginosa, namely, multiple-locus variable-number tandem-repeat (VNTR) typing with high-resolution melting analysis (HRMA). The technology was used to genotype a collection of 43 environmental and clinical strains isolated during an outbreak in a neonatal intensive care unit (NICU) that we report. Nineteen strains isolated in other departments or outside the hospital were also tested. The genetic diversity of this collection was determined using VNTR-HRMA, with amplified fragment length polymorphism (AFLP) analysis as a reference. Twenty-five and 28 genotypes were identified, respectively, and both techniques produced congruent data. VNTR-HRMA established clonal relationships between the strains of P. aeruginosa isolated during the outbreak in the NICU and proved, for the first time, the role of mineral water as the inoculum source. VNTR typing with one primer pair in association with HRMA is highly reproducible and discriminative, easily portable among laboratories, fast, and inexpensive, and it demonstrated excellent typeability in this study. VNTR-HRMA represents a promising tool for the molecular surveillance of P. aeruginosa and perhaps for molecular epidemiologic analysis of other hospital infections.

Correlations between genotyping and antibiograms of clinical isolates of Pseudomonas aeruginosa from three different south Indian hospitals

PURPOSE

To compare the molecular relationships and antibiograms of nosocomial isolates of Pseudomonas aeruginosa obtained from three different genres of hospitals located in Southern India, two located at Hyderabad (one private hospital and an ophthalmic hospital) and one in Puducherry (tertiary care teaching hospital). Each of these hospitals, which follow different infection control strategies and various problems associated with it, were investigated.

MATERIALS AND METHODS

Antibiograms generated by disk diffusion susceptibility testing for clinically relevant antibiotics and genotyping through fluorescent amplified fragment length polymorphism analysis (fAFLP) were the tools used in the study.

RESULTS

Molecular genotyping revealed a heterogeneous group of unrelated molecular clusters of P. aeruginosa strains having higher resistance that are apparently being endemic throughout the tertiary care teaching hospital. In eye care hospital, only a few distinct strains of P. aeruginosa predominating the study period were shown to be responsible for outbreaks. The third private hospital witnessed a group of resistant and persistent strains that might have clonally originated from a diverse collection of strains.

CONCLUSIONS

The divergent kind of strains in our study suggests that there may be a direct link between the infection control practices followed in each hospital and kind of strains isolated in that particular setup. The study also emphasizes the need for maintaining infection control practices in hospitals with superior standards, failure of which might result in thriving of persistent P. aeruginosa clones in the hospitals.

Pathogenic phenotype and genotype of Pseudomonas aeruginosa isolates from spontaneous canine ocular infections

PURPOSE

This study was designed to determine whether the ability to adversely affect corneal epithelial cell health is a factor common to Pseudomonas aeruginosa keratitis strains and to assess the prevalence of each pathogenic phenotype and genotype in a canine model of naturally-acquired P. aeruginosa ocular infection.

METHODS

P. aeruginosa ocular isolates were collected by sampling 100 dogs without disease (six isolates collected) and by sampling dogs with conjunctivitis (two isolates), endophthalmitis (one isolate), active keratitis (12 isolates), and resolved P. aeruginosa keratitis (four isolates). Phenotype was determined in vitro by quantifying corneal epithelial cell invasion by gentamicin survival assays, and cytotoxic activity by Trypan blue exclusion assays. Genotyping was performed for genes encoding the type III secreted effectors.

RESULTS

The ratio of invasive to cytotoxic strains with 95% confidence intervals (CI) was 0.83 (CI, 0.42-0.99) for conjunctival microflora isolates, 0.80 (CI, 0.54-0.94) for ocular infection isolates, and 1.0 (CI, 0.45-1.0) for strains isolated post-resolution of keratitis. Among ocular infection isolates, invasive and cytotoxic strains were significantly (P

CONCLUSIONS

Invasive strains predominated in the dogs of this study. Only keratitis strains had visible adverse effects on epithelial cells without overt cytotoxicity, suggesting virulence strategies affecting live corneal epithelial cell health are selected for among keratitis strains.

Collapse

Key Words Collapse

MESH Headings

• Animals
• Anti-Bacterial Agents/pharmacology
• Conjunctivitis, Bacterial/drug therapy
• Conjunctivitis, Bacterial/microbiology
• Conjunctivitis, Bacterial/veterinary
• Corneal Ulcer/drug therapy
• Corneal Ulcer/microbiology
• Corneal Ulcer/veterinary
• Dog Diseases/drug therapy
• Dog Diseases/microbiology
• Dogs
• Endophthalmitis/drug therapy
• Endophthalmitis/microbiology
• Endophthalmitis/veterinary
• Eye Infections, Bacterial/drug therapy
• Eye Infections, Bacterial/microbiology
• Eye Infections, Bacterial/veterinary
• Genotype
• Microbial Sensitivity Tests/veterinary
• Phenotype
• Pseudomonas Infections/drug therapy
• Pseudomonas Infections/microbiology
• Pseudomonas Infections/veterinary
• Pseudomonas aeruginosa/drug effects
• Pseudomonas aeruginosa/genetics

Collapse

Grants

• R01 EY011221 NEI NIH HHS
• R01-EY011221 NEI NIH HHS

Collapse

Affiliation(s)

Eric C Ledbetter College of Veterinary Medicine, Department of Clinical Sciences, Cornell University, Ithaca, New York 14853-6414, USA.
James J Mun
David Kowbel
Suzanne M J Fleiszig

Collapse

Collaborators Collapse