Enteric Gram Research Articles

2250. Fluoroquinolone Stewardship at a Veterans Affairs Facility: A Six Year Review

Abstract Background Increased utilization of antibiotics leads to decreased antimicrobial susceptibility, a well-established phenomenon. Antimicrobial stewardship programs (ASP) promote appropriate prescribing of antibiotics by decreasing inappropriate use, aiming to improve patient outcomes and reducing antimicrobial resistance. Fluroquinolones (FQ) are among the most prescribed antibiotics. We describe out institutional FQ use since inception of our ASP and followed the trend for susceptibility of Enterobacteriaceae and Pseudomonas Methods Northport Veterans Affairs Medical Center (VAMC) provides care for over 30000 Veterans in Long Island, New York, with emergency room, acute care hospital, nursing homes and outpatient clinics A Retrospective review investigated FQ use by total refills per year and by days of therapy per 1000 patient days at Northport VAMC from 2012 to 2022, along with review of local annual antibiograms focusing on ciprofloxacin susceptibility to E. coli, K. pneumoniae, P. mirabilis and P. aeruginosa. An ASP in our facility was initiated in 2016. FQs are restricted antibiotics and require approval by the infectious diseases team (attendings, fellows, pharmacist) Results Figure 1 provides the outpatient total fills per year for Ciprofloxacin, Levofloxacin, Moxifloxacin. Inpatient FQ use during the ASP years was low: Figure 2 shows the FQ inpatient use (days of therapy/1000days) from 2019 to 2022. Comparing years 2012-2016 vs 2017-2022 there was a decrease in fills of ciprofloxacin (median 604 vs. 308 fills, P: 0.009), levofloxacin (276 vs. 116, P: 0.032), and moxifloxacin (116 vs. 14, P: 0.015). By same period comparison (see figure 3), Ciprofloxacin susceptibility for E. coli ranged median 66.5% to 61.5%, P: 0.126, K. pneumoniae 67% vs. 75.5% P: 0.086, P. mirabilis 45% vs. 47.5% P: 0.451, and P. aeruginosa 63% vs. 68.5% P: 0.308 Figure 2 inpatient FQ use 2019 to 2022 Figure 3 Ciprofloxacin susceptibility trend over time Conclusion There was a statistically significant decrease in the use of FQ in the outpatient setting after ASP was initiated in our facility. Although there was a trend in improvement in ciprofloxacin susceptibilities for Klebsiella, Proteus, and Pseudomonas, it was not statistically significant. Nevertheless, our results show that reducing FQ consumption can prevent worsening susceptibility trends for enteric gram negatives and Pseudomonas. Disclosures All Authors: No reported disclosures

Phytochemical Screening and Antibacterial Activity of the Crude Extract of Scent Leaf (Ocimum gratissimum) on Escherichia coli and Staphylococcus aureus

Scent (Ocimum gratissimum) leaves are known for their medicinal values for a long. The study was carried out on phytochemical screening and antibacterial activity of scent leaf extracts on E. coli and S. aureus. Antibacterial assay of the plant extracts was carried out on the test isolates, by inoculation on the surface of freshly gelled sterile nutrient agar plates by streaking using sterilized swab stick and the potent extracts was determined according to the macro broth dilution technique. Phytochemical screening of O. gratissimum leaves revealed the presence of steroids, saponins, flavonoids, alkaloids, cardiac glycosides and tannins in all the extracts. There was decreased in antibacterial activity with decreased in concentration of the extract as the concentration of the extract decreases from 200 – 25 mg/ml, the zones of inhibition also decreased from 20 to 11 mm (ethanol extract) and 17 – 10 mm (aqueous extract) for S. aureus; 19 – 10 mm (ethanol extract) and 15 – 8 mm (aqueous extract) for E. coli. The Minimum Inhibitory Concentration (MIC) of O. gratissimum extracts against the selected clinical isolates revealed no growth (clear) in all the test organisms at the concentration of 200 mg/ml. Also, the Minimum Bactericidal Concentration (MBC) showed no growth of bacterial colonies at the concentration of 200 mg/ml. It was observed from the study that ethanol and aqueous extracts exhibited high inhibitory activities on Escherichia coli a representative of enteric coliforms and Gram negative bacteria and Staphylococcus aureus a representative of Gram positive bacteria. Ethanolic extract had higher inhibition compared to the aqueous extract. This can be deduced to the ability of ethanol to extract more of the essential oils and secondary plant metabolites which are believed to exert antibacterial activity on the test organisms.

Characterization of Respiratory Pathogens in Contemporary Lung Transplant Recipients

This study assessed respiratory pathogens isolated in the first year post lung transplant in a recent multicenter cohort. Prior studies may not reflect current practices in antimicrobial prophylaxis and molecular diagnostics. We examined 499 consecutive bronchoalveolar lavage (BAL) samples for microbial isolates in 82 lung transplant recipients (LTR) enrolled in the prospective Genomic Research Alliance for Transplantation from July 2015 to 2017. Isolates were examined for species, timing: early (0-1 months post-transplant (MPT), intermediate (1-6 MPT), and late (6-12 MPT), and associated lung function decline. 389 microbes were isolated in 499 BAL samples, representing 348 unique episodes, over a median of 196 days. Bacterial isolates were more common in the early and intermediate periods, and fungal and viral pathogens more common in the late period. In non-Cystic Fibrosis (CF) populations, the frequencies of most common bacterial isolates S. aureus, P. aeruginosa, and enteric Gram Negative Bacteria were 15.6%, 12.6%, 23.0%, compared to 28.0%, 30.0%, and 18.0% respectively, in CF LTRs. The most common viral pathogens were rhinovirus (60.6%), and enterovirus (12.7%). Non-invasive molds (Penicillium etc) comprised 73.3% of fungal isolates, with potentially invasive molds (Aspergillus, Mucor sp.) isolated in 12.9% of cases. Notably, there were only two isolates of Aspergillus fumigatus (2.0%). 48/389 isolates (12.3%) were associated with > 10% reduction in FEV1 at 90 days post isolation of which rhinovirus was the most frequent isolate (11/48). In a contemporary cohort, bacterial pathogens predominate in the early post-transplant period, while fungal and viral pathogens are more common later. Pseudomonas and Aspergillus sp. comprised a smaller proportion of total than previously described, and do not appear to associate with early lung function decline. Further studies are underway to determine the conditions in which select infections impact early lung function.

Assessment of clinical and epidemiological characteristics of patients with and without sepsis in intensive care units of a tertiary hospital.

ABSTRACTObjective To describe the clinical and epidemiological features of patients with and without sepsis at critical care units of a public hospital.Methods A cross-sectional study was carried out from May 2012 to April 2013. Clinical and laboratory data of patients with and without sepsis in the intensive care units were reviewed of medical records.Results We evaluated 466 patients, 58% were men, median age was 40 years, and 146 (31%) of them were diagnosed with sepsis. The overall mortality was 20% being significantly higher for patients with sepsis (39%). The factors associated with intensive care unit mortality were the presence of sepsis (OR: 6.1, 95%CI: 3.7-10.5), age (OR: 3.6, 95%CI: 1.4-7.2), and length of hospital stay (OR: 0.96, 95%CI: 0.94-0.98). Pulmonary (49%) and intra-abdominal (20%) infections were most commonly identified sites, and coagulase-negative staphylococci and enteric Gram negative bacilli the most frequent (66%) pathogens isolated.Conclusion Although the impact of sepsis on mortality is related to patients’ clinical and epidemiological characteristics, a critical evaluation of these data is important since they will allow the direct implementation of local policies for managing this serious public health problem.

To Compare the Bacterial Reduction from the Infected Root Canals Using ProTaper Universal, WaveOne and NeoNiTi Instrumentation Systems

Anticipation of root canal bacteria contamination is the foundation of endodontic treatment. The most predominant type is Enterococcus Faecalis strain, along with which several Gram negative enteric rods or Gram positive facultative may also be present. The aim of the present study was to compare the bacterial reduction from the infected root canals taking samples of pre-chemomechanical and post-chemomechanical preparation by ProTaper Universal, WaveOne and NeoNiTi instrumentation systems. Seventy-five systematically healthy patients was selected with permanent mandibular premolar teeth with single root and single canal. They are divided in three: Group I (ProTaper Universal), Group II (WaveOne) and Group III (NeoNiTi), in which each individual pre and post instrumentation sample of microorganism was taken and then analyzed using Paired ‘t’ test, One Way ANOVA with Post HOC comparison using Tukey test for microbiological evaluation. When pre-chemomechanical samples were compared by applying One-Way ANOVA test, the difference in pre-chemomechanical values in all three groups was statistically insignificant (p>0.05). Statistical analysis by applying paired ‘t’ test, One-Way ANOVA and p value showed that there was highly statistically significant change from pre-chemomechanical values to post-chemomechanical values in each study group (p<0.001). There was highly statistically significant difference in CFU count percentage reduction between the pre-instrumentation and post-instrumentation values in all the groups (p<0.001). Group I (ProTaper Universal) showed the highest percentage reduction followed by Group III (NeoNiTi) and Group II (WaveOne). Statistical analysis by paired ‘t’ test and p value showed that the reduction in number of colony forming units from S1 (pre-instrumentation) to S2 (post-instrumentation) was statistically highly significant (p<0.001). It may be concluded that the most effective instrumentation technique in eliminating microorganisms from the root canal was ProTaper Universal system in comparison to WaveOne and NeoNiTi.

Prevalence and Emergence of Extended-Spectrum Cephalosporin-, Carbapenem- and Colistin-Resistant Gram Negative Bacteria of Animal Origin in the Mediterranean Basin.

In recent years, extended ESBL and carbapenemase producing Gram negative bacteria have become widespread in hospitals, community settings and the environment. This has been triggered by the few therapeutic options left when infections with these multi-drug resistant organisms occur. The emergence of resistance to colistin, the last therapeutic option against carbapenem-resistant bacteria, worsened the situation. Recently, animals were regarded as potent antimicrobial reservoir and a possible source of infection to humans. Enteric Gram negative bacteria in animals can be easily transmitted to humans by direct contact or indirectly through the handling and consumption of undercooked/uncooked animal products. In the Mediterranean basin, little is known about the current overall epidemiology of multi-drug resistant bacteria in livestock, companion, and domestic animals. This review describes the current epidemiology of ESBL, carbapenemase producers and colistin resistant bacteria of animal origin in this region of the world. The CTX-M group 1 seems to prevail in animals in this area, followed by SHV-12 and CTX-M group 9. The dissemination of carbapenemase producers and colistin resistance remains low. Isolated multi-drug resistant bacteria were often co-resistant to non-beta-lactam antibiotics, frequently used in veterinary medicine as treatment, growth promoters, prophylaxis and in human medicine for therapeutic purposes. Antibiotics used in veterinary medicine in this area include mainly tetracycline, aminoglycosides, fluoroquinolones, and polymyxins. Indeed, it appears that the emergence of ESBL and carbapenemase producers in animals is not related to the use of beta-lactam antibiotics but is, rather, due to the co-selective pressure applied by the over usage of non-beta-lactams. The level of antibiotic consumption in animals should be, therefore, re-considered in the Mediterranean area especially in North Africa and western Asia where no accurate data are available about the level of antibiotic consumption in animals.

Assessment of Foods and Drinks for the Presence of Extended Spectrum Beta Lactamase (ESBL) Producing Bacteria in Gombe Metropolis, Nigeria

Objectives: To make preliminary screening study for the presence of ESBL producing bacteria, in food and drinks sold in Gombe metropolis. 30 samples of food and drinks were collected and analyzed. Method: Bacterial isolation was performed on nutrient agar and identification started from gram staining; the gram negative isolates obtained, among which ESBL producers were found and further subjected to standard biochemical tests and confirmed to be enterobacteriaceae. They were then screened for ESBLs in accordance with Clinical and Laboratory Standard Institute (CLSI) breakpoint, and the suspected ESBLs bacteria were confirmed using double disc synergy testing (DDST) with standard Augmentin (Amoxycillin/ Clavulanic Acid, 30μg; Oxoid England, CT0223B), Ceftriaxone (CRO 30μg; Oxoid England, CT0417B) and Ceftazidime (CAZ 30μg; Oxoid England, CT0412B). Findings: The fourteen 14(100%) Gram negative bacteria isolated were found to include Pseudomonasaeruginosa 2(14.29%) and members of the family Enterobacteriaceae (enteric gram negative rods): Citrobacterfreundii 2(14.29%), Enterobacterspp. 1(7.14%), Escherichiacoli 4(28.57%), Klebsiellapneumoniae 3(21.43%), Proteusvulgaris 1(7.14%) and Salmonellatyphi 1(7.14%). When screened for ESBL production based on CLSI breakpoint, only 6 (49.99%) were positive and included C.freundii 1(7.14%), E.coli 2(14.29%), K.pneumoniae 1(7.14%), S. typhi 1(7.14%) and 1(7.14%) for Ps. aeruginosa. On subjecting them to DDST, only 2(33.34%) out of them were found to be ESBLs positive by an increase in inhibition zone of 5mm toward the centre disc, Augmentin. They include E. coli 1(16.67%) and S. typhi 1(16.67%). Application: In a nutshell, foods and drinks sold therein could serve as reservoirs for ESBLs producing bacteria.

Antibiotic Resistance Pattern and Stewardship Programme in Critical Care Settings

Sensitivity pattern of isolates from patients’ specimens associated with infection, admitted to the critical care centers with empiric or prophylactic antibiotic use were assessed. Till identification of the organism and resultant sensitivity awaited; and compared with sensitive antibiotic to the isolates which could be used for management. This analytical cross sectional study carried out during the period of April 2016 to July 2016 in the Critical Care Centre (CCC) of Combined Military Hospital, Dhaka Cantonment. Urine and other specimens including wound swab, pus, sputum, tracheal aspirate, catheter tip, nasal swab, high vaginal swab, broncheoalveolar lavage, blood, urethral discharge were collected from the patients following aseptic precautions. Isolate identification was done using standard procedures at the Armed Forces Institute of Pathology (AFIP). Sensitivity was tested using antibiotic disc diffusion technique. A total of one thousand six hundred and seventy patients were dealt with in the study, and positive yield obtained in 190 (11.38%) cases. Of those, 116 were urine specimens which constituted 69 (57.76%) female and 47(42.24%) male patients. A total of 1088 discs of antibiotics were used on an average 9 discs per isolate. Six hundred and forty nine (59.65%) showed resistance to the antibiotic used against them, while four hundred and thirty nine (40.35%) showed sensitive response. The study population was of 2-80 years age group. Other specimens included 74 isolates, fifty (67.57%) were males and twenty four (32.43%) were females. A total of eight hundred and twenty seven (11.18 discs per isolate) antibiotic doses were used 479 (57.92%), showed resistant and 348 (42.08%) sensitive result. Enteric gram negative bacilli (GNB) were the majority of isolates in both types of specimens. The study indicated that, newer antimicrobials have a substantial impact in decreasing human morbidity and mortality rates. It encourages to expand surveillance of antibiotic resistance determinants and to exercise caution in dispensing antibiotics to maximize their continued efficacy. Excess or injudicious use is causing increase in cost as well as inducing drug resistance among the common bacterial isolates. A work on the clinical presentation with trends of antimicrobials used in the CCC setup right now in tertiary care hospital would be of supplemental value for the study.

English

Extended spectrum beta-lactamases (ESBLs) are enzymes that are now becoming major sources of resistance to &beta;-lactamase antibiotics more especially in enteric bacteria such as Klebsiella pneumoniae, P. aeruginosa and Escherichia coli. Increase in the frequency of the &beta;-lactam resistance in bacteria has become a serious threat for treating bacterial infections caused by enterobacteriaceae. This study aims to determine the prevalence of ESBLs producers among enteric Gram negative bacteria isolated from patients in OAUTHC, Ile-Ife, Osun State. The subject used in this study involved patients presenting with evidence of hospital infections. The collected sputum specimens were processed for the isolation and identification of Gram negative bacilli. Resistance of the isolates to different antibiotics tested was determined using the standard disc diffusion method of Kirby-Bauer. Phenotypic and confirmatory test of the isolates were done for ESBL production using double disc synergy test (DDST) on Mueller Hinton agar according to CLSI 2013 guidelines. Results reveal that the highest occurrence of bacteria was recovered in Klebsiella species (35%), followed by Enterobacter sp. (13%), P. aeruginosa (10%), Escherichia coli and Salmonella sp. (7%) while the least occurs in Proteus sp. All the isolates were 100% resistance to class piperacillin, 76.6% to beta-lactamase inhibitor and 52% resistance to cephalosporins while they were susceptible to carbapenems, nitrofurans, and fluoroquinolones. The prevalence of ESBLs producing isolates was 51.1% while non-ESBL producing strains were 48.8%. Therefore, it can be concluded that extended spectrum beta lactamases are gradually increasing in Nigeria with co-resistance to some other classes of antibiotics which is very alarming. There is a limited number of drugs sensitivity for these bacteria and the drug of choice is imipenem, ciprofloxacin and ofloxacin. Key words: Multidrug resistance, extended spectrum beta-lactamases (ESBLs), Gram negative bacteria

EFFECT OF MICROBIAL CONTAMINATION WITH FUNGI, AFLATOXIN M1 AND ENTERIC GRAM NEGATIVE BACTERIA ON MILK AND SOME DAIRY PRODUCTS

milk and milk products are excellent high quality foods, providing nutritional values through important elements in the healthy human diet. In this study, 75 samples of dried milk, raw milk, butter, cream and cooked (processed) cheese (15 of each) were collected randomly from various dairy shops and supermarkets in Giza Governorate, and tested microbiologically for fungal and enteric gram negative bacterial contamination; detection of AFM1 residues using ELISA technique as well as detection of lipolytic and proteolytic activities of the most isolated fungi and bacteria. Six genera of moulds were recovered from the examined samples and three genera of yeasts. The most isolated moulds were species of genera Penicillium followed by Aspergillus, Cladosporium, Geotrichum, Mucor and Scopulariopsis, while the most isolated yeasts were species of genera Candida followed by Rhodotorula and Saccharomyces. AFM1 levels were detected in all analyzed samples of raw milk and milk products. AFM1 levels exceed EU legal limits (50 ppt) (0.05 μg/L/kg) while the detected limits were below the international legal limits of USA (FDA) (500 ppt) (0.50 μg/L/kg) in raw milk and dairy products for human consumption. The highest lipolytic and proteolytic activities were detected in A. niger and Mucor spp. (100%) while Cladosporium spp. possessed the lowest activities (50%), Candida albicans had activities (80%) and Rhodotorula had activities (62.5% and 75%). Pseudomonas spp. isolates were examined for proteolytic and lipolytic activities; three isolates had lipolytic activity (27.27%), also three isolates had proteolytic activity (27.27%). On the other hand,the most isolated enteric gram negative bacteria from the examined samples were identified as E. coli followed by species of Psudomonas, Klebsiella, Shigella and Salmonella. Moreover, no any bacteria were isolated from butter and dry milk samples. The economic importance and public health significance to the present results as well as apply the proposed sanitary measures to reduce microbial contamination and food safety for human health were discussed.

Escherichia coli Resistance to Ciprofloxacin in Acute Uncomplicated Pyelonephritis

Background: Severe acute uncomplicated pyelonephritis is an infection of the kidneys that usually have an ascending route and occur in presumably healthy urinary tract. The most common pathogen involved is E. coli. The Infectious Diseases Society of America (IDSA) has issued an updated guideline in 2010 suggesting IV quinolones to be considered in the initial empiric antimicrobial therapy giving known resistance of less than 10%. However, E. coli resistance to quinolones has been increasing, the recent data of E. coli, causing pyelonephritis, resistance is not known in the Midwest. Local hospital antibiogram for two years showed up to 22% resistance to ciprofloxacin among E. coli isolates. Methods: We conduct a retrospective non-concurrent cohort study in one teaching hospital in the Midwest, females who were admitted with severe acute uncomplicated pyelonephritis in a three years period were included. Patients with urinary tract obstruction, pregnancy, immuno-suppression, males, and indwelling Foley’s catheters were excluded. Data collected include causative pathogens and resistance to antibiotics were collected. Percentages, frequencies, and measures of central tendency and dispersion were calculated to describe the study sample Results: 73 patients were included in the final analysis. E. coli was the most common isolated pathogen (81%), followed by other enteric gram negative. E. coli resistance to ciprofloxacin was 13.5%, 37% to trimethoprim-sulfamethoxazole, and 5% to ceftriaxone. Conclusion: Ciprofloxacin should be avoided initially in treating severe acute uncomplicated pyelonephritis until culture results and sensitivity is available.

Assessment of Foods and Drinks for the Presence of Extended Spectrum Beta Lactamase (ESBL) Producing Bacteria in Gombe Metropolis, Nigeria

Objectives: To make preliminary screening study for the presence of ESBL producing bacteria, in food and drinks sold in Gombe metropolis. 30 samples of food and drinks were collected and analyzed. Method: Bacterial isolation was performed on nutrient agar and identification started from gram staining; the gram negative isolates obtained, among which ESBL producers were found and further subjected to standard biochemical tests and confirmed to be enterobacteriaceae. They were then screened for ESBLs in accordance with Clinical and Laboratory Standard Institute (CLSI) breakpoint, and the suspected ESBLs bacteria were confirmed using double disc synergy testing (DDST) with standard Augmentin (Amoxycillin/ Clavulanic Acid, 30μg; Oxoid England, CT0223B), Ceftriaxone (CRO 30μg; Oxoid England, CT0417B) and Ceftazidime (CAZ 30μg; Oxoid England, CT0412B). Findings: The fourteen 14(100%) Gram negative bacteria isolated were found to include Pseudomonasaeruginosa 2(14.29%) and members of the family Enterobacteriaceae (enteric gram negative rods): Citrobacterfreundii 2(14.29%), Enterobacterspp. 1(7.14%), Escherichiacoli 4(28.57%), Klebsiellapneumoniae 3(21.43%), Proteusvulgaris 1(7.14%) and Salmonellatyphi 1(7.14%). When screened for ESBL production based on CLSI breakpoint, only 6 (49.99%) were positive and included C.freundii 1(7.14%), E.coli 2(14.29%), K.pneumoniae 1(7.14%), S. typhi 1(7.14%) and 1(7.14%) for Ps. aeruginosa. On subjecting them to DDST, only 2(33.34%) out of them were found to be ESBLs positive by an increase in inhibition zone of 5mm toward the centre disc, Augmentin. They include E. coli 1(16.67%) and S. typhi 1(16.67%). Application: In a nutshell, foods and drinks sold therein could serve as reservoirs for ESBLs producing bacteria.

Antimicrobial Activity of Ephedra pachyclada Methanol Extract on Some Enteric Gram Negative Bacteria Which Causes Nosocomial Infections by Agar Dilution Method

Background: Past history indicates that plants were served as an important source of medicine. Otherwise, in developing countries people use medicinal plants against infectious disease because they cannot afford expensive drugs. Due to increasing rate of drug-resistant diseases, there is an urgent need to detect novel antimicrobial compounds from medicinal plants. Objectives: The aim of the present study was to determine Antimicrobial activity of Ephedra pachyclada methanol extract on some enteric Gram-negative bacteria which causes nosocomial infections by agar dilution method. Methods: In this cross-sectional study, in order to examine the antimicrobial effects of Ephedra pachyclada extract on intestinal Gram-negative bacteria, we exposed them to 0/128, 0/25, 0/5, 1, 2, 4 and 8 mg/mL of the extract. Ephedra pachyclada was collected from Jiroft Heights and methanolic extract was prepared with maceration method, during which, 50 gr powder of Ephedra pachyclada was dissolved in 300 mL of 80% methanol. Results: In this study, the antibacterial effects of Ephedra pachyclada extract on Gram-negative bacteria such as Pseudomonas aeruginosa, Escherichia coli (PTCC-O157), Escherichia coli (ATCC-25922), Klebsiella pnemoniae, Serratia marcescens was investigated, defining the minimum inhibitory concentration (MIC) by agar dilution method. It has been demonstrated that methanolic extract of Ephedra pachyclada affect intestinal Gram-negative bacteria. Conclusions: The result showed that, Ephedra pachyclada extract has effective antimicrobial ingredients which are cheap and readily available. It can be used for medicinal purposes in the production of antimicrobial drug.

Prevalence and Antimicrobial Susceptibility Patterns of Enteric Gram Negative Bacteria in the Intensive Care Units of Kenyatta National Hospital

To investigate the prevalence of Enteric Gram negative bacteria and their antimicrobial susceptibility patterns in Intensive Care Units of Kenyatta National Hospital. No documented study has been done in Kenyatta National Hospital to determine the trends of antimicrobial susceptibility patterns in Intensive Care Units. The study was a laboratory-based study. All the clinical specimens received in the laboratory for culture and sensitivity from Intensive Care Units were subjected to the study. Isolation of Enteric gram-negative bacteria from clinical specimens and identification to the species level was performed by standard methods. Microbiology Laboratory, Kenyatta National Hospital, Kenya. The most prevalent microorganisms were found to be <em>Klebsiella pneumoniae</em> (10.5%), <em>Citrobacterfreundii</em> (8.6%), <em>Enterobacter</em> spp (5.2%), <em>Escherichia coli</em> (5.1%), <em>P. aeruginosa</em> (4.6%), <em>Proteus mirabilis</em> (3.2%) and S.typhimurium (0.14%). A percentage resistance of 10% or less was considered low and a percentage resistance of 50% and above was taken to be high. Moderate resistance was taken to be varying from 11 to 49%. <em>Citrobacterfreundii</em>, <em>Proteus mirabilis</em>, <em>E. coli</em> and <em>Enterobacter spp</em> showed high resistance to at least six antibiotics tested. <em>Klebsiella</em> and <em>Pseudomonas spp</em> showed high resistance to five and four antibiotics respectively. Moderate resistance was exhibited by all the six micro-organisms to an average of five antibiotics tested. Gram negative bacteria, specifically <em>Klebsiellapneumoniae</em>., <em>Enterobacter spp</em>., <em>Citrobacterfreundii., E.coli</em>, <em>P. aeruginosa</em> and <em>Proteus mirabilis</em>. are prevalent in the Intensive Care Units of Kenyatta National Hospital.Isolated micro-organisms exhibited antimicrobial resistance to five commonly used antimicrobials.

Antimicrobial Susceptibility of Enteric Gram Negative Facultative Anaerobe Bacilli in Aerobic versus Anaerobic Conditions.

Antimicrobial treatments result in the host’s enteric bacteria being exposed to the antimicrobials. Pharmacodynamic models can describe how this exposure affects the enteric bacteria and their antimicrobial resistance. The models utilize measurements of bacterial antimicrobial susceptibility traditionally obtained in vitro in aerobic conditions. However, in vivo enteric bacteria are exposed to antimicrobials in anaerobic conditions of the lower intestine. Some of enteric bacteria of food animals are potential foodborne pathogens, e.g., Gram-negative bacilli Escherichia coli and Salmonella enterica. These are facultative anaerobes; their physiology and growth rates change in anaerobic conditions. We hypothesized that their antimicrobial susceptibility also changes, and evaluated differences in the susceptibility in aerobic vs. anaerobic conditions of generic E. coli and Salmonella enterica of diverse serovars isolated from cattle feces. Susceptibility of an isolate was evaluated as its minimum inhibitory concentration (MIC) measured by E-Test® following 24 hours of adaptation to the conditions on Mueller-Hinton agar, and on a more complex tryptic soy agar with 5% sheep blood (BAP) media. We considered all major antimicrobial drug classes used in the U.S. to treat cattle: β-lactams (specifically, ampicillin and ceftriaxone E-Test®), aminoglycosides (gentamicin and kanamycin), fluoroquinolones (enrofloxacin), classical macrolides (erythromycin), azalides (azithromycin), sulfanomides (sulfamethoxazole/trimethoprim), and tetracyclines (tetracycline). Statistical analyses were conducted for the isolates (n≥30) interpreted as susceptible to the antimicrobials based on the clinical breakpoint interpretation for human infection. Bacterial susceptibility to every antimicrobial tested was statistically significantly different in anaerobic vs. aerobic conditions on both media, except for no difference in susceptibility to ceftriaxone on BAP agar. A satellite experiment suggested that during first days in anaerobic conditions the susceptibility changes with time. The results demonstrate that assessing effects of antimicrobial treatments on resistance in the host’s enteric bacteria that are Gram negative facultative Anaerobe Bacilli requires data on the bacterial antimicrobial susceptibility in the conditions resembling those in the intestine.

Distribution and Antimicrobial Susceptibility Pattern of Blood Stream Pathogens in a Tertiary Care Hospital from Suburban, Mumbai

In the era of multidrug resistance it is essential to know the exact organisms causing blood stream infections (BSI) with its antimicrobial susceptibility pattern for effective management of BSI. Blood cultures from clinically diagnosed BSI cases were processed by BacT/ALERT microbial detection system. Pure isolates were identified by mini API system and antimicrobial susceptibility test was done by ATB Reader. Out of 552 blood culture samples, 81(14.67%) were culture positive. Predominant isolates were gram positive cocci (GPC) 43 (53.09%) followed by enteric gram negative bacilli (GNB) 28 (34.57%). Coagulase negative Staphylococci (CONS) 29 (35.80%) was the most significant pathogen. All the CONS were sensitive to Vancomycin and Linezolid and resistant to commonly used drugs like Penicillin 4 (13.79%), Vancomycin and Linezolid sensitivity was 100% in GPC. Among GNB 100% sensitivity was seen to Imipenem followed by Pipercillin-Tazobactam 34 (97.14%). Both GPC and GNB were multidrug resistant.

Risk factors for acquisition of extended spectrum beta lactamase producing Escherichia coli and Klebsiella pneumoniae in North-Indian hospitals

Multidrug resistance and production of extended spectrum β-lactamases (ESBLs) by enteric gram negative rods in hospitals and community continue to be a matter of scientific concern. This retrospective study was executed to assess the prevalence of ESBL-producing Escherichia coli and Klebsiella pneumoniae at two North Indian hospitals and to determine the risk factors associated with the acquisition of these organisms. A total of 346 bacterial isolates were obtained. Of these, 48.27% (n=167) were confirmed to be ESBL producers while 51.73% (n=179) were non ESBL-producers. Among the ESBL producers, 55.69% (n=93) were E. coli and 44.31% (n=74) were K. pneumoniae. ESBL producing isolates showed co-resistance to multitude of antibiotics tested. Length of hospital stay (>3days) and previous exposure to antibiotics were found as significant risk factors (p=0.01 and 0.02) associated with the acquisition of ESBL-producing E. coli and K. pneumoniae isolates. Imipenem and meropenem can be suggested as drugs of choice in our study.

777

Introduction: ECMO cannulation typically occurs in the operating room (OR), however emergent situations may warrant cannulation outside of the OR, where sterility and aseptic technique may be compromised. Although no consensus guideline recommendations exist for antibiotic prophylaxis, patients typically receive cefazolin and vancomycin for peri-operative prophylaxis for 48 hours at our institution. This study aims to compare the incidence of infection between emergent (EC) and non-emergent cannulation (NEC). Secondary aims included examining predominant microorganisms and time to infection. Methods: This retrospective, single-center, cohort study included patients > 18 years of age who received initial ECMO between January 1, 2009 and June 30, 2012. Patients were excluded if initial cannulation was at an outside hospital or if ECMO duration was < 24 hours. EC was defined as taking place outside the OR and NEC was defined as taking place inside the OR. Infections were defined according to the CDC/NHSN health-care associated infection definitions and were evaluated during two timeframes: pre-ECMO (72 hours pre-cannulation up until time of cannulation) and post-ECMO (time of cannulation to 72 hours post-decannulation). Results: Seventy-three patients were included in the study; 39 received EC and 34 received NEC. There were no differences between groups in terms of demographics or ECMO characteristics. The prevalence of infection at the time of cannulation was similar between groups, EC 8/39 (21%) vs. NEC 5/34 (15%), p=0.58. The incidence of infection after cannulation was similar between groups, EC 8/39 (21%) vs. NEC 7/34 (21%), p=0.99. Eleven (73%) infections occurred within the first 7 days on ECMO. Gram (-) bacteria were the most common pathogens, accounting for 67% (n=10) of the infections. Importantly, most gram (-) isolates observed would not have been covered by our standard antibiotic prophylaxis. Specific isolates include: Enterobacter spp. (n=3), Pseudomonas spp. (n=2), Acinetobacter spp. (n=2), and other enteric gram (-) (n=3). Conclusions: The urgency of cannulation did not affect infection risk. Infections occurred early and were predominantly gram negative. These data may have important implications for the design of antibiotic prophylaxis regimens in the future.

Prevalence and Antimicrobial Susceptibility Pattern of Uropathogenic Escherichia coliamong Adult Diabetic Patients Attending Federal Medical Centre Gombe, Gombe State Nigeria

Two hundred urine samples were collected from patients attending diabetic clinic at the Federal Medical Centre Gombe (FMCG). The samples were cultured on nutrient agar and the isolates obtained were Gram-stained, subjected to biochemical tests to confirm their identities. All the 200 samples were found to contain Gram negative organisms. Of the 200 gram negative isolates obtained, 111(55.5%) were found to be positive for E. coli while the remaining, 89(44.5%) were found to be negative for E. coli but positive for other enteric gram negative rods(Enterobacteriaceae). Female diabetic patients recorded higher incidence of 85(77%) than their male counterparts of 26(23%). Antimicrobial susceptibility testing was carried out against the isolated E. coli using Kirby-Bauer (1966) method and shows the activity of only members of Aminoglycosides, streptomycin and Gentamycin as moderately sensitive and highly sensitive respectively. Other antibiotics proved inactive, to which the E. coli became resistant, and these include Septrin, chloramphenicol, quinolones (Sparfloxacin, ciprofloxacin, Peploxacin and Tarivid) and augmentin (Maxi high profile Gram negative antibiotics).

Colangitis bacteriémica en adultos en un hospital general en Chile

Some aspects of bacteremic cholangitis are unknown in Chile. To gather more information on clinical, microbiological aspects as well as risk factors for ICU admission, recurrence and antimicrobial resistance. A retrospective research was performed using medical records of adult patients in a general hospital. Between 2006-2012, 22 patients with 29 bacteremic events were identified. Previous cholangitis events were reported by 27.3%, 45.5% had recent admissions and, 50% had used antimicrobial compounds. Coledocholithiasis was the most common cause of obstruction (45.5%) followed by cancer (36.4%). One third developed shock (31%), the only factor associated with ICU admission (OR 30, p < 0.05). In 24 of the 29 bacteremic events, the biliary tract was intervened (82.8%) and in 80.8% during the first 72 hours. Gram negative bacilli were predominant (> 80%) and some infrequent agents such as Staphylococcus warneri, Shewanella spp. and, Aeromonas spp. were observed. Among enteric gram negative bacilli, 29.2% presented fluoroquinolone resistance and, 26.1% resistance to third generation cephalosporins, both associated with previous endoscopic retrograde cholangiography (OR 35 and 16.5, respectively p < 0.05). A favorable response was observed in 93.1% of bacte-remic events but in 31.8% of patients cholangitis recurred with or without bacteremia. Recurrence was associated to recent admission (OR 16.5, p = 0.01) and in all cases occurred before 81 days. In-hospital mortality was 9.1% (n = 2), but in only one case associated to sepsis. Average length of stay (LOS) was 17.8 days. Early intervention of the biliary tract allows a favorable response in patients affected by bacteremic cholangitis, but this condition use intensive care resources, had a prolonged LOS, a recurrent pattern, and is associated with several bacterial species, some of them resistant.