Spectrum of bacterial keratitis in North India: A retrospective analysis of six years at a tertiary care eye center

Purpose: To analyze the pattern of bacterial pathogens causing infective keratitis and their resistance to the recommended antibiotics over six years. Methods: It was a retrospective study of 9,357 cases of bacterial keratitis from January 2015 to December 2020, at a tertiary care ophthalmic center. A total of 9,547 corneal specimens were obtained from the study subjects. Demographic details of the patients, pathogenic bacteria isolated, and their antimicrobial susceptibility were noted and analyzed. Results: Bacterial pathogens were identified in 23.52% of the specimens. The most common isolates were coagulase?negative Staphylococci (60.75%), followed by Pseudomonas aeruginosa (14.23%), Staphylococcus aureus (13.92%), gram negative bacilli of the family Enterobacterales (8.64%), Streptococcus spp. (1.72%), Acinetobacter spp. (0.13%), and other non?fermenting gram?negative bacilli (0.57%). In Staphylococci, 55–80% of isolates were resistant to erythromycin, and 40–70% to fluoroquinolones, while no resistance was observed against vancomycin. 40–60% of isolates of P. aeruginosa were resistant to cephalosporins, 40–55% to fluoroquinolones, and 30–60% to aminoglycosides. Also, 40–80% of isolates of Enterobacterales were resistant to cephalosporins, and 50–60% to fluoroquinolones. Most gram?negative isolates were susceptible to carbapenems and polymyxin B. Conclusion: To the best of our knowledge, our study is the largest compilation of microbiological profile of bacterial keratitis from North India. It highlights the current trend of the bacterial pathogens that cause infectious keratitis. Staphylococci and Pseudomonas were found to be the most common pathogens. Increased resistance was seen against some of the commonly prescribed empirical antibiotics. Such evidence is useful for restructuring the empirical prescription practices from time to time.

Bacterial culture of bile from patients with obstructive jaundice and antibiotic sensitivity / 中国内镜杂志

Objective To investigate the characteristics of microbial isolates and the positive rate from bile cultures taken from obstructive jaundice patients, then compare the antimicrobial sensitivities to guide the rational choice and use of antibiotics. Methods Bile cultures from 322 patients from January 2012 to April 2016 were reviewed. Specimens were obtained from patients that were diagnosed obstructive jaundice. The bile specimens were examined for pathogenic respectively. At the same time, the empirical antibiotics of the 322 cases prior to operation were also analyzed. Results Bile culture was positive in 246 among322 cases, the positive culture rate was 76.40%. A total of 267 pathogens were isolated in bile culture: 208 Gram-negative bacteria, 48 Gram-positive bacteria and 11 fungus. The most common pathogens in all were Escherichia coli (208 strains, 53.18%), Enterococcus faecium (28 strains, 10.49%), Klebsiella pneumoniae (27 strains, 10.11%). The most sensitive antibiotics against Gram-negative bacteria were imipenem and meropenem (with susceptibility rate for 98.08%, respectively). The more sensitive antibiotics against Gram-negative bacteria were efoperazone/sulbactam, amikacin, piperacillin/tazobactam (susceptibility 92.31%, 88.46% and 85.58%). The lowest susceptibility rate of Gram-negative to twelve kings of antimicrobial agents were levofloxacin, andaztreonam (susceptibility 29.81%, 28.37%). The most sensitive antibiotics against Gram-positive bacteria were linezolid, teicoplanin and vancomycin(with susceptibility rate for 100.00%, respectively). The more sensitive antibiotics against Gram-positive bacteria was chloromycrtin (susceptibility 88.89%). The lower susceptibility rate of Gram-positive were levofloxacin (susceptibility 25.00%). 281 cases of patients before surgery empirical use of antimicrobial drugs. Monotherapy was used in 219 cases. The main drug was levofloxacin (86/219), the second was cefoperazone/sulbactam (70/219). The dual therapy was used in 62 cases, the mainly was cefoperazone/sulbactam plus ornidazole or metrornidazole(27/62), the second was levofloxacin plus ornidazole or metrornidazole (12/62). Conclusions Gram negative bacteria were the predominant bile pathogens found in patients with obstructive jaundice. And the most prominent Gram-negative pathogens were Escherichia coli. The sensitive rates of cefoperazone/sulbactam, amikacin and piperacillin/tazobactam were higher, which could be used as the preferred antimicrobial agents. Imipenem and meropenem should remain the last alternative when all other therapies fail or serious infection; The empirical antibiotics's pertinence was not very suitable, levofloxacin's resistance rates in obstructive jaundice was higher. It should be avoided to choose during empirical antimicrobial therapy.

Antibiotics Susceptability of Streptococcus pneumoniae Isolated from Pharynx in Healthy Korean Children and Choice of Proper Empirical Oral Antibiotics Using Pharmacokinetics/Pharmacodynamics Model / 소아감염

PURPOSE: Pneumococcus is one of the most important causes of invasive infection through the childhood period. In January 2008, the Clinical and Laboratory Standards Institute (CLSI) published revised penicillin breakpoints for Streptococcus pneumoniae and penicillin susceptibility rates of S. pneumoniae increased in Korea. This study was performed to determine the probability of oral amoxicillin for the empirical treatment achieving bactericidal exposure against pneumococcus using pharmacodynamics model. METHODS: Twenty-three isolates of pneumococci were subjected to determine minimum inhibitory concentration (MIC) for beta-lactams and macrolide. For the beta-lactams, exposure of fT >MIC (time that free drug concentrations remain above the MIC) for 50% of the administration interval have determined the probability of target attainment (PTA), and regimens that had a PTA >90% were considered optimal. An analysis was performed by applying MIC of 23 isolates to a 5000-patient Monte Carlo simulation model. RESULTS: Among 23 isolates from healthy children, 7 (30.4%) isolates were MIC 90% at MIC < or =1.0 microg/mL but PTA decreased to 52% at MIC 2 microg/mL, whereas amoxicillin 90 mg/kg/day can predict 97% of PTA at MIC 2 microg/mL. Overall, oral amoxicillin 90 mg/kg/day for the empirical treatment against pneumococcus can expect more successful response in Korean children. CONCLUSION: Considering the resistantce pattern of pneumococci in Korean children, we estimate that oral amoxicillin 90 mg/kg/day will provide a pharmacodynamic advantage for the empirical treatment against pneumococcus. And low dose amoxicillin or macrolide are expected to have higher chance of treatment failure than high dose oral amoxicillin.

Listeria Sepsis and Pneumonia in a Premature Neonate

Listeria monocytogenes (L. monocytogenes) is a foodborne anaerobic gram-positive rod and the third most common pathogen for neonatal meningitis. Although the mortality and morbidity of L. monocytogenes infections are high, thus causing serious problems in Western populations, neonatal listeriosis is relatively rare in Eastern countries, including Korea. Possible routes for intrauterine infection or vertical transmission of L. monocytogenes include infected placentas and the reproductive tract. Intrauterine infections may cause chorioamnionitis, preterm labor, spontaneous abortion, stillbirth, or neonatal infection. A high index of suspicion and early empirical antibiotic treatment are critical to achieve a favorable prognosis for neonatal listeriosis. We managed a case of L. monocytogenes sepsis and pneumonia in a premature neonate born at 26 weeks of gestational age from an asymptomatic mother with culture-proven placental infection. The neonate was successively treated with ampicillin and gentamicin.

Microbiology and Antibiotic Selection for Diabetic Foot Infections / 대한족부족관절학회지

PURPOSE: To help the empirical antibiotics selection in diabetic foot infection patients, we investigated prevalence of microorganisms and their antibiotics sensitivity results. MATERIALS AND METHODS: Patients who came to our clinics to treat diabetic foot infections with deep ulceration and were followed up more than 6 months until complete recovery were adopted. From March 2006 to June 2009, there were 140 patients who corresponded with such a inclusion criteria. Wound cultures were done by deep tissue or bone debris at first visit to our clinics. Microorganisms which was documented by wound culture and most susceptible antibiotics by minimum inhibitory concentrations were surveyed retrospectively. RESULTS: Microorganisms were confirmed in 113 cases (80.7%). In the other 27 cases (19.3%), there were no cultured microorganisms. In bacterial growth group, there were 72 cases (63.7%) of gram-positive bacteria and 41 cases (36.3%) of gramnegative bacteria. All of them were aerobic microorganisms and there were no anaerobic microorganisms. Methicillin-sensitive staphylococcus aureus was the most common pathogen and accounted for 35 cases (31.0%). As other common pathogens, there were Enterobacter cloacae (11 cases, 9.7%), pseudomonas aeruginosa (10 cases, 8.8%), Methicillin-resistant staphylococcus aureus (10 cases, 8.8%) and enterococcus faecalis (6 cases, 5.3%), and so on. Common susceptible antibiotics in gram positive microorganism were vancomycin (60 cases, 83.3%), teicoplanin (60 cases, 83.3%), nitrofurantoin (60 cases, 83.3%) and ciprofloxacin (53 cases, 73.6%). In gram negative ones, common susceptible antibiotics were imipenem (35 cases, 85.3%), piperacillin/tazobactam (33 cases, 80.5%) and gentamicin (31 cases, 75.6%). CONCLUSION: Methicillin-sensitive Staphylococcus aureus in gram positive and enterobacter cloacae in gram negative was the most common pathogen in each group. Ciprofloxacin and gentamicin might be adaptable as a first-line empirical antibiotics in infected diabetic foot patients.

A case of Listeriosis in early third trimester pregnant woman / 대한산부인과학회지

Although listeria monocytogenes is widely distributed in nature, it rarely causes clinical infection in previously healthy people. However, this microorganism may cause severe infectious disease in pregnant women and newborns due to impaired cell-mediated immunity. Various clinical symptoms have been described such as sepsis, central nervous system infections, endocarditis, gastroenteritis and localized infections. A clinical presentation of listeriosis in an early third trimester pregnant woman and in a preterm infant is emphasized in addition to taking a careful patient history, early empirical administration of antibiotics, aggressive ventilation therapy and also pharmacological support.

The Effects of Initial Empirical Antibiotics Regimens on the Outcomes of Staphylococcus aureus Bacteremia / 감염

BACKGROUND: Because of the concern for the emergence of resistance, the prudent use of vancomycin is essential. However, it is uncertain whether the initial delay in the effective treatment of Staphylococcus aureus bacteremia adversely affects the outcome. We performed this study to determine the outcome of an initial delay in the use of antistaphylococcal antibiotics for Staphylococcus aureus bacteremia (SAB). METHODS: We conducted a retrospective cohort study of 238 with SAB at a tertiary care hospital. Empirical antibiotics treatment was considered ineffective if the isolated strain was not susceptible, in vitro, to antibiotics given during the first 48 hours. The outcome was measured as SAB-related mortality within 8 weeks from the SAB. RESULTS: The mortality for the patients with ineffective empirical regimen (50/117, 42.7%) showed a trend toward being higher than that with effective empirical regimen (38/121, 31.4%), but it did not reach the statistical significance (OR 1.63 95% CI 0.96~2.77, P=0.07). However, in the subgroups of end-stage renal disease ineffective empirical antibiotics adversely affected the outcomes (OR 5.42, 95% CI 1.25~23.49, P=0.02) On multivariate logistic regression analysis, adjusted OR of ineffective empirical regimen for SAB-related mortality was 2.03 (95% CI 1.08~3.82, P=0.03). CONCLUSION: Our findings suggest that an initial delay in the use of antistaphylococcal antibiotics for the first 2 days might adversely affect the outcome when treating SAB, especially in the patients with end-stage renal disease.

Efficacy of the Antibiotics Chosen by ATS Guideline in the Treatment of Korean Patients with Community-acquired Pneumonia Admitted to a Tertiary Hospital / 결핵

BACKGROUND: In 1993, American Thoracic Society (ATS) recommended a guideline for the initial management of adults with community-acquired pneumonia(CAP). However, etiologic organisms and medical system in Korea seem to be different from those in Western countries. Retrospective analysis was done to evaluate the efficacy of antibiotics chosen by ATS guideline in the treatment of Korean patients with CAP admitted to a tertiary university medical center. METHODS: Hospitalized patients with CAP at Samsung Medical Center from April 1997 through March 1998 were retrospectively reviewed. Patients who fulfilled all of the following criteria were included in this study : (1) fever >or=38degrees C (2) purulent sputum (3) pulmonary infiltrates on chest X-ray. Patients were classified as : 1) ATS group ; patients whose initial antibiotics were chosen by ATS guideline 2) Non-ATS overuse group ; additional antibiotics administered more than those of ATS guideline, and 3) Non-ATS underuse group ; initial antibiotics were insufficient to ATS guideline. Response of empirical antibiotics and etiologic organisms of 3 groups were identified. RESULTS: Sixty-four patients were enrolled. Thirty-six patients were classified into ATS group, 10 patients Non-ATS overuse group, and 18 patients Non-ATS underuse group. Thirty-three patients of 36 ATS group, 9 patients of 10 Non-ATS overuse group, and 14 patients of 18 Non-ATS underuse group showed improvement by initial empirical antibiotics. There was no statistical difference in antibiotic response between 3 groups (p>0.05). S. pneumoniae (12.5%), K. pneumoniae(9.4%), and P. aeruginosa(4.7%), Mycoplasma(3.1%) were the most commonly isolated organisms. In 18 patients with severe CAP, P. aeruginosa was isolated only in 1 patient and Legionella organism not isolated. CONCLUSION: Initial empirical antibiotics chosen by ATS guideline were effective in the management of Korean patients with CAP admitted to a tertiary hospital. However well-designed large-scale prospective study is needed to identify etiologic organisms and choose an adequate initial empirical antibiotics in Korean adults patient with severe CAP.