anti-Pseudomonas Agents Research Articles

202. The effectiveness of combination therapy of anti-methicillin-resistant Staphylococcus aureus agents and β-lactam agents in patients complicated with febrile neutropenia after bone marrow transplantation

BackgroundFebrile neutropenia (FN) is one of the most frequent and serious complications of hematopoietic stem cell transplantation such as bone marrow transplantation (BMT). Anti-Pseudomonas agents should be initiated in all patients complicated with FN without delay, while anti–methicillin-resistant Staphylococcus aureus (MRSA) agents are exclusively recommended in the case of central venous (CV) line infection. Most BMT patients have the potential risk of catheter-related blood stream infection because of long-lasting catheterization including indwelling CV line. Therefore, the patients may also be received anti-MRSA agents empirically in addition to anti-Pseudomonas agents. So far, there are little reports that verify the effectiveness of the combination therapy under FN condition after BMT. The purpose of this study was to address the effectiveness.MethodsBMT was performed at Yokohama City University Medical Center between April 2012 and March 2018, and 44 patients who developed FN after BMT were enrolled. We analyzed patient information retrospectively. We used the duration of fever to evaluate the additive effect of anti-MRSA agents to β-lactam anti-Pseudomonas agents. We classified the patients during FN period into two groups whether anti-MRSA agents were administered (Ad group; 34 patients) or not (non-Ad group; 10 patients). Fever is defined as a single axillary temperature measurement of over 37.5 Celsius degrees. The study design and protocol were approved by the ethics committee at the Review Board of our hospital (ID：D1602011).ResultsBaseline characteristics were similar between the two groups. Blood cultures were performed onset of FN in all cases, in which five showed positive (11.4%). Bacteria requiring administration of anti-MRSA drugs were detected in the four cases. Nonetheless, duration of fever was not significantly shorten (6.8 ± 4.0 vs. 5.2 ± 2.5, P = 0.171) and there was no difference in the hospitalization period. The renal dysfunction was significantly higher in Ad group and the cost of anti-MRSA agents totaled about $ 36,000.ConclusionOur study indicates that no use of empirical combination therapy of anti-MRSA agents in addition to anti-Pseudomonas agents under FN condition after BMT, even if CV line is inserted. Disclosures All authors: No reported disclosures.

Expression of a Pseudomonas aeruginosa-targeted antimicrobial peptide T9W in Bacillus subtilis using a maltose-inducible vector

Abstract The T9W is a variant of pig myeloid antimicrobial peptide-36 (PMAP 36) that displays efficient and specific activity against Pseudomonas aeruginosa. It may represent a promising agent for anti-pseudomonas therapies, so a large quantity of T9W is needed for pharmacological study and clinical use. Recombinant T9W was successfully produced by Bacillus subtilis WB800 N using the maltose-inducible promoter Pglv. After 36 h of induction by 5% maltose, 6×His-SUMO-T9W was directly secreted into culture medium. Then, 6×His-SUMO-T9W was purified by Ni-NTA affinity chromatography, and then 32 mg/L of fusion peptide was obtained. Then, the purified 6×His-SUMO-T9W was digested by SUMO protease, thus releasing the recombinant T9W. Recombinant T9W showed high antimicrobial activity against Pseudomonas aeruginosa and extremely weak activity against other gram-negative (Escherichia coli, Salmonella typhimurium) and gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus). When the concentration of recombinant T9W reached the maximum (256 μM), no hemolytic activity was observed. Recombinant T9W has similar activity to synthetic T9W. These results suggested that this method provided an economical and environmentally friendly approach to producing anti-pseudomonas agent T9W in Bacillus subtilis.

English

Pseudomonas aeruginosa is a Gram negative aerobic rod shaped bacterium and is an opportunistic pathogen that usually causes nosocomial infection in immunocompromised patient with various infections and affects normal healthy human as well. P. aeruginosa is also an omnipresent pathogen that can be inhabited in soil, water, vegetable, human and animal. Metallo-β-lactamases (MBL) producing P. aeruginosa are known to be resistant to almost the entire anti-pseudomonas agent via mechanism of low outer membrane permeability, β-lactamases synthesis and the efflux systems. This study was conducted to detect the potential of metallo-β-lactamases producing P. aeruginosa presence in water samples from various parts of Malaysia. In this study, 52 water samples were collected from various parts of Malaysia. These P. aeruginosa isolates were processed to these phenotypic methods, Hodge test which is used to detect the carbapenemase production, Imipenem- EDTA combined disc test (CDT). Imipenem-EDTA double disc synergy test (DDST) was used to determine metallo-beta-lactamases producing P. aeruginosa. Among 52 various sources of water samples, 13 water samples had positive P. aeruginosa isolates. 6 out of 13 positive isolates have shown positive results in Hodge test, CDT and DDST. All metallo-β-lactamases producing isolates are multi-drug resistant. Among water samples from various parts of Malaysia, MBL producing P. aeruginosa are highly found in Selangor followed by KL, and this P. aeruginosa are detected from drain followed by river. Although some advantages and disadvantages exist among these phenotyping methods, still CDT and DDST are optimal to detect MBL. Key words: Metallo-β-lactamases, multi-drug resistance, phenotyping method, Pseudomonas aeruginosa.

Antibiotic resistant Pseudomonas spp. in the aquatic environment: A prevalence study under tropical and temperate climate conditions

Microbial populations which are resistant to antibiotics are an emerging environmental concern with potentially serious implications for public health. Thus, there is a growing concern in exploring the occurrence of antibiotic resistance in the environment with no limitations to the factors that contribute to their emergence. The aquatic environment is considered to be a hot-spot for the acquisition and spread of antibiotic resistance due to pollution with emerging contaminants derived from anthropogenic activities. In this study, we report on the isolation and characterization of 141 Pseudomonas spp. from aquatic sediments receiving partially (un)treated hospital and communal effluents from three distinct geographical locations: Democratic Republic of the Congo (DRC), India (IN), and Switzerland (CH). P. putida (42%) and P. aeruginosa (39%) were the dominant Pseudomonas species. The highest frequency of antibiotic resistance against eight anti-pseudomonas agents was found among IN isolates (35–60%), followed by DRC (18–50%) and CH (12–54%). CTX-M was the most frequent β-lactamase found in CH (47% of isolates), while VIM-1 was dominant in isolates from DRC (61%) and IN (29%). NDM-1 was found in 29% of the total IN isolates and surprisingly also in 6% of CH isolates. Chromosomally-encoded efflux mechanisms were overexpressed in P. aeruginosa isolates from all three geographic locations. In vitro conjugative transfers of antibiotic resistance plasmids occurred more frequently under tropical temperatures (30 and 37 °C) than under temperate conditions (10 °C). The presence of Extended Spectrum β-lactamases (ESBLs) and Metallo β-lactamases (MBLs) in the isolates from environmental samples has important implications for humans who depend on public water supply and sanitation facilities. To our knowledge, this is the first study to demonstrate a comparison between treated/untreated effluents from urban and hospital settings as a source of microbial resistance by evaluating the aquatic ecosystems sediments from tropical and temperate climate conditions. Taken together, our findings demonstrate a widespread occurrence of antibiotic resistance in aquatic ecosystems sediments receiving untreated/treated wastewater and how these contemporary sources of contamination, contribute to the spread of microbial resistance in the aquatic environment. This research presents also useful tools to evaluate sediment quality in the receiving river/reservoir systems which can be applied to similar environments.

Exposure to Reactive Oxygen Species and Piperacillin Leads to Multidrug Resistance in Pseudomonas aeruginosa PAO1

Pseudomonas aeruginosa is one of the most common causes of nosocomial infections. Hospital associated infection by multidrug resistant (MDR) strains constitute a serious problem worldwide. The aim of the present study was to evaluate whether exposure to sub-MIC levels of anti-pseudomonas antibiotics and reactive oxygen species (ROS), such as hydroxyl radicals, could lead to MDR of P. aeruginosa. P. aeruginosa standard strain PAO1 was used in this study. All five anti-pseudomonas agents, that is, piperacillin, levofloxacin, meropenem, ceftazidime and amikacin, were investigated for induction of resistance and cross-resistance in vitro. The reference strain was incubated 24 h and transferred 5 times after being exposed to 1 mM H2O2 in addition to a sub-MIC of each antibiotic by the agar dilution method. When cross-resistance to another antibiotic was confirmed, ampC, mexAB, and oprD expression and mutation of QRDR were investigated. Sub-MIC of piperacillin induced resistance to piperacillin and levofloxacin under stimulation with ROS. The mechanism of multi-resistance to β-lactams and levofloxacin was confirmed by RT-PCR. It was a decrease of oprD expression (p<0.05). The increase of MIC was inhibited by the ROS scavenger sodium zinc histidine dihydrolipoyl histidinate (DHL-His-Zn). In conclusion, for P. aeruginosa PAO1 to acquire multidrug resistance, stimulation with ROS was as important as exposure to sub-MIC of piperacillin.

Computer-aided discovery in antimicrobial research: In silico model for virtual screening of potent and safe anti-pseudomonas agents.

Resistance of bacteria to current antibiotics is an alarming health problem. In this sense, Pseudomonas represents a genus of Gram-negative pathogens, which has emerged as one of the most dangerous species causing nosocomial infections. Despite the effort of the scientific community, drug resistant strains of bacteria belonging to Pseudomonas spp. prevail. The high costs associated to drug discovery and the urgent need for more efficient antimicrobial chemotherapies envisage the fact that computeraided methods can rationalize several stages involved in the development of a new drug. In this work, we introduce a chemoinformatic methodology devoted to the construction of a multitasking model for quantitative-structure biological effect relationships (mtk-QSBER). The purpose of this model was to perform simultaneous predictions of anti-Pseudomonas activities and ADMET (absorption, distribution, metabolism, elimination, and toxicity) properties of organic compounds. The mtk-QSBER model was created from a large and heterogeneous dataset (more than 54000 cases) and displayed accuracies higher than 90% in both training and prediction sets. In order to demonstrate the applicability of our mtk-QSBER model, we used the investigational antibacterial drug delafloxacin as a case of study, for which experimental results were recently reported. The predictions performed for many biological effects of this drug exhibited a remarkable convergence with the experimental assays, confirming that our model can serve as useful tool for virtual screening of potent and safer anti-Pseudomonas agents.

Sodium houttuyfonate inhibits virulence related motility of Pseudomonas aeruginosa

Sodium houttuyfonate (SH) is a derivative of effective component of a Chinese material medica, Houttuynia cordata, which is applied in anti-infection of microorganism. But, the antimicrobial mechanisms of SH still remain unclear. Here, we firstly discovered that SH effectively inhibits the three types of virulence related motility of.Pseudomonas aeruginosa, i.e., swimming, twitching and swarming. The plate assay results showed that the inhibitory action of SH against swimming and twitching in 24 h and swarming in 48 h is dose-dependent; and bacteria nearly lost all of the motile activities under the concentration of 1 x minimum inhibitory concentration (MIC) (512 mg x L(-1) same as azithromycin positive group (1 x MIC, 16 mg x L(-1)). Furthermore, we found that the expression of structural gene flgB and pilG is down-regulated by SH, which implies that inhibitory mechanism of SH against motility of P. aeruginosa may be due to the inhibition of flagella and pili bioformation of P. aeruginosa by SR Therefore, our presented results firstly demonstrate that SH effectively inhibits the motility activities of P. aeruginosa, and suggest that SH could be a promising antipseudomonas agents in clinic.

Efflux-mediated fluoroquinolone resistance in the multidrug-resistant Pseudomonas aeruginosa clinical isolate PA7: identification of a novel MexS variant involved in upregulation of the mexEF-oprN multidrug efflux operon.

The emergence of multidrug-resistant Pseudomonas aeruginosa has become a serious problem in medical settings. P. aeruginosa clinical isolate PA7 is resistant to fluoroquinolones, aminoglycosides, and most β-lactams but not imipenem. In this study, enhanced efflux-mediated fluoroquinolone resistance of PA7 was shown to reflect increased expression of two resistance nodulation cell division (RND) -type multidrug efflux operons, mexEF-oprN and mexXY-oprA. Such a clinical isolate has rarely been reported because MexEF-OprN-overproducing mutants often increase susceptibility to aminoglycosides apparently owing to impairment of the MexXY system. A mutant of PA7 lacking three RND-type multidrug efflux operons (mexAB-oprM, mexEF-oprN, and mexXY-oprA) was susceptible to all anti-pseudomonas agents we tested, supporting an idea that these RND-type multidrug efflux transporters are molecular targets to overcome multidrug resistance in P. aeruginosa. mexEF-oprN-upregulation in P. aeruginosa PA7 was shown due to a MexS variant harboring the Valine-155 amino acid residue. This is the first genetic evidence shown that a MexS variant causes mexEF-oprN-upregulation in P. aeruginosa clinical isolates.

Expansion of Antibacterial Spectrum of Muraymycins toward Pseudomonas aeruginosa.

It is urgent to develop novel anti-Pseudomonas agents that should also be active against multidrug resistant P. aeruginosa. Expanding the antibacterial spectrum of muraymycins toward P. aeruginosa was investigated by the systematic structure-activity relationship study. It was revealed that two functional groups, a lipophilic side chain and a guanidino group, at the accessory moiety of muraymycins were important for the anti-Pseudomonas activity, and analogue 29 exhibited antibacterial activity against a range of P. aeruginosa strains with the minimum inhibitory concentration values of 4-8 μg/mL.

Antimicrobial Resistance Patterns and Prevalence of blaPER-1 and blaVEB-1 Genes Among ESBL-producing Pseudomonas aeruginosa Isolates in West of Iran.

Background:Pseudomonas aeruginosa is a leading cause of nosocomial infections worldwide. Resistance of P. aeruginosa strains to the broad-spectrum cephalosporins may be caused by extended-spectrum β-lactamases (ESBLs).Objectives:The aim of this study was to determine the antimicrobial resistance patterns and prevalence of PER-1 and VEB-1 type genes among ESBL producing strains of P. aeruginosa.Material and Methods:A total of 106 P. aeruginosa isolates were collected from two university hospitals in Hamadan, Iran, during a7-month study (2009). The antimicrobial susceptibility of isolates was determined by disc diffusion method and interpreted according to the clinical and laboratory standards institute (CLSI) recommendations. Production of ESBL was determined by combined disk test and presence of PER-1 and VEB-1 type ESBL genes was identified by PCR.Results:The resistance against broad-spectrum cephalosporins and monobactames were: cefepime (97%), cefotaxime (92.5%) ceftazidime (51%), and aztreonam (27%). Ciprofloxacin (91.5%), imipenem (84.9%) and meropenem (82.1%) were the most effective anti-pseudomonas agents in this study. The results revealed that 88.7% of the isolates were multidrug resistant, 58.25% of those were ESBL positive. Sixteen (26.6%), 9 (15%) and 3 (5%) strains among ESBL-producing strains contained blaPER-1, blaVEB and blaPER-1-blaVEB, respectively.Conclusions:This study highlighted the need to establish antimicrobial resistance surveillance networks for P. aeruginosa to determine the appropriate empirical treatment regimens. The high prevalence of multidrug resistance and production of ESBLs in P. aeruginosa isolates confirms the necessity of protocols considering these issues in the hospitals.

Anti-&lt;i&gt;Pseudomonas aeruginosa&lt;/i&gt; Compound, 1,2,3,4-Tetrahydro-1,3,5-triazine Derivative, Exerts Its Action by Primarily Targeting MreB

In order to find new anti-Pseudomonas agents, we carried out whole-cell based P. aeruginosa growth assay, and identified 1,2,3,4-tetrahydro-1,3,5-triazine (Compound A). This compound showed anti-Pseudomonas activity against wild as well as pumpless strain equally at a same concentration. Also, this compound was structurally very similar to A22, which is known to inhibit the bacterial actin-like protein MreB. By the analysis of resistant strains, the primary target of this compound in P. aeruginosa was definitely confirmed to be MreB. In addition, these compounds showed a bacteriostatic effect, and induced the morphology changes in P. aeruginosa from rod shape to sphere shape, which leads to be clinically favorable in terms of susceptibility to phagocytosis and release of endotoxin. These results display that Compound A is a very attractive compound which shows anti-P. aeruginosa activity based on inhibition of MreB without being affected by efflux pumps, and could provide a new step toward development of new promising anti-Pseudomonas agents, MreB inhibitors.

Profile of microorganisms and antimicrobial resistance at a tertiary care referral burn centre in Iran: Emergence of Citrobacter freundii as a common microorganism

Infection and antimicrobial resistance are important issues in severe burn. The aims of this prospective study were to investigate the profile of microorganisms and resistance to antimicrobial agents in a tertiary referral burn centre; 113 people aged >10 years, with partial- or full-thickness burns, were included in the study. A total of 733 samples including 275 swabs, 164 tissue biopsies, 258 urine samples, 26 blood samples and 10 sputum samples were collected, from which 124 microorganisms were isolated. Pseudomonas aeruginosa and Citrobacter spp were the most prevalent isolates (57.3% and 35.5%, respectively); 95.5% of Citrobacter. isolates were Citrobacter freundii. Antibiogram results obtained from 15 antimicrobial agents demonstrated that imipenem was the most effective agent against P. aeruginosa, followed by ciprofloxacin and piperacillin/tazobactam (67.9%, 43% and 37.5% sensitive, respectively). At least 60% of all Citrobacter isolates were sensitive to various antimicrobial agents, the highest sensitivity being obtained by ceftazidime and cefepime (81.6% and 78.4%, respectively). Sensitivity of P. aeruginosa isolates to the agents of each antimicrobial class was significantly different ( p < 0.001). The incidence of C. freundii and the resistance of P. aeruginosa to anti-pseudomonas agents were exceptionally high.

Comparison of antimicrobial cycling and mixing strategies in two medical intensive care units*

To compare a mixing vs. a cycling strategy of use of anti-Pseudomonas antibiotics on the acquisition of resistant Gram-negative bacilli in the critical care setting. Prospective, open, comparative study of two strategies of antibiotic use. Two medical intensive care units of a university hospital. A total of 346 patients admitted for >or=48 hrs to two separate medical intensive care units during an 8-month period. Patients, who according to the attending physician's judgment required an anti-Pseudomonas regimen, were assigned to receive cefepime/ceftazidime, ciprofloxacin, a carbapemen, or piperacillin-tazobactam in this order. "Cycling" was accomplished by prescribing one of these antibiotics during 1 month each. "Mixing" was accomplished by using the same order of antibiotic administration on consecutive patients. Interventions were carried out during two successive 4-month periods, starting with mixing in one unit and cycling in the other. Swabbing of nares, pharynx, and rectum and culture of respiratory secretions were obtained thrice weekly. The main outcome variable was the proportion of patients acquiring enteric or nonfermentative Gram-negative bacilli resistant to the antibiotics under intervention. The scheduled cycling of antibiotics was only partially successful. Although the expected antibiotic was the most prevalent anti-Pseudomonas agent used within the corresponding period, it never accounted for >45% of all anti-Pseudomonas antimicrobials administered. During mixing, a significantly higher proportion of patients acquired a strain of Pseudomonas aeruginosa resistant to cefepime (9% vs. 3%, p = .01), and there was a trend toward a more frequent acquisition of resistance to ceftazidime (p = .06), imipenem (p = .06), and meropenem (p = .07). No differences in the rate of acquisition of potentially resistant Gram-negative bacilli or incidence of intensive care unit-acquired infections and infections due to particular organisms were observed. In critically ill medical patients, a strategy of monthly rotation of anti-Pseudomonas beta-lactams and ciprofloxacin may perform better than a strategy of mixing in the acquisition of P. aeruginosa resistant to selected beta-lactams.

Severe ciprofloxacin-associated pseudomembranous colitis in an eight-year-old child

Clostridium difficile is the principal cause of antibiotic-associated diarrhea and pseudomembranous enterocolitis in children. A case of severe pseudomembranous colitis developing in an 8-year-old child who had received oral ciprofloxacin therapy as part of an investigational protocol is presented. The safety and efficacy of fluoroquinolones in children has not yet been established. Use of these antibiotics in children outside investigational protocols (“off-label” use) as oral antipseudomonas agents is discouraged.

Small-colony variants of Pseudomonas aeruginosa in cystic fibrosis.

In the context of chronic lung infection due to Pseudomonas aeruginosa in cystic fibrosis (CF), attention has been focused on the presence of the most common mucoid phenotype. In this study, the presence of small-colony variants (SCVs) of P. aeruginosa in respiratory tract specimens from patients with CF was investigated, and the clinical conditions predisposing to SCVs were analyzed. P. aeruginosa SCVs were isolated from 33 of 86 P. aeruginosa-positive CF patients over a 2-year period. Fast-growing revertants with larger surface colonies could be isolated from SCV populations. Electron microscopy revealed no significant difference in cell size or morphology. MICs of a broad range of antipseudomonas agents for SCVs were two- to eightfold higher than values for revertants. Recovery of SCVs was correlated with parameters revealing poor lung function and was significantly associated with daily inhalation of tobramycin or colistin.

Evaluation of reference dilution test methods for antimicrobial susceptibility testing of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis.

The development of multidrug-resistant Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is most likely a consequence of increasing life expectancy and more prolonged exposure to antibiotics. The optimal method for antibiotic susceptibility testing of CF strains, particularly mucoid P. aeruginosa strains, is unknown. Antimicrobial susceptibilities of 48 CF strains (25 mucoid) and 50 non-CF strains to 12 anti-Pseudomonas agents were tested by both agar dilution and commercially custom-prepared broth microdilution plates (PML Microbiologicals, Portland, Oreg.) in three laboratories simultaneously to determine if broth microdilution could substitute for agar dilution as the reference method in subsequent studies. Comparison of MICs generated by agar dilution and broth microdilution demonstrated correlation coefficients (r) exceeding 0.85 for all agents tested; correlation was excellent for aminoglycosides (r >/= 0.92) and very good for beta-lactam agents including agents paired with a beta-lactamase inhibitor (r >/= 0.87) and for ciprofloxacin (r = 0.86). Correlation was not improved by 48-h readings, but correlation between 24- and 48-h readings ranged between 0.91 and 0.98 for both methods. Interlaboratory variations were minimal, as the percentage of acceptable variations was 94% for both methods, and serious discords were infrequent (<2% of comparisons). However, CF strains were more likely to have serious discords than were non-CF strains (P < 0. 0001), although mucoid strains were not more likely to have serious discords than were nonmucoid strains. In this study, MICs determined by custom-prepared broth microdilution compared favorably with MICs determined by agar dilution. Thus, this broth microdilution assay can serve as a reference method and facilitate future studies to determine the optimal method for antibiotic susceptibility testing of CF strains.

Antibiotic susceptibility of multiply resistant Pseudomonas aeruginosa isolated from patients with cystic fibrosis, including candidates for transplantation.

Chronic lung disease caused by antibiotic-resistant Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is difficult to treat, especially in those who are lung transplantation candidates. Analysis of antibiotic susceptibility and synergy studies of 1,296 isolates revealed that 172 (13.3%) were multiply resistant (i.e., resistant to two or more classes of anti-Pseudomonas agents). beta-Lactam agents (including imipenem and aztreonam) or aminoglycosides inhibited only 11% of the multiply resistant strains, while ciprofloxacin inhibited 34%. High concentrations of tobramycin and gentamicin (200 micrograms/mL), achievable by aerosol administration, inhibited 95% of isolates and overwhelmed permeability-resistance mechanisms. Antimicrobial pairs tested in checkerboard dilutions of clinically achievable drug concentrations inhibited 75% of the multiply resistant strains. On average, three additive and 2.4 synergistic pairs of antimicrobial agents had activity per strain. Transplantation candidates were older than nontransplantation candidates (P = .034), and isolates from transplantation candidates were less likely to be inhibited by antibiotic combinations (P < .001). Administration of aerosolized aminoglycosides and synergy testing of antimicrobial combinations may represent viable therapeutic options for patients with CF.

Malignant external otitis in a diabetic adolescent

Malignant external otitis (MEO) is an unusual medical problem. The case reported is that of a diabetic adolescent who presented with severe ear pain unresponsive to oral antibiotics and analgesics. The diagnosis of MEO was made, and he was successfully treated with a combination of intravenous anti-Pseudomonas agents. A review of the pediatric cases, guidelines for diagnosis, length of treatment, and prognosis are presented.

In-vitro activity of carbenicillin and results of treatment of infections due to Pseudomonas with carbenicillin singly and in combination with gentamicin.

ginosa is highly resistant to most antimicrobial agents [2]. Although most strains are sensitive to the polymyxin group of antibiotics in vitro, clinical effectiveness of these drugs in infections of tissue has been disappointing, probably because the polymyxins diffuse poorly into infected tissues [3]. Most clinical isolates of P. aeruginosa are also sensitive to gentamicin, and this antibiotic is now probably the most effective drug for the treatment of infections due to Pseudomonas [4]. However, the clinical dosage and effectiveness of gentamicin is limited by potential toxicity to the kidney and eighth nerve [5], and there still remains a need for an anti-Pseudomonas chemotherapeutic agent of greater effectiveness and lower toxicity. In 1966, Brumfitt, et al. [6] reported that a new penicillin, carbenicillin, was moderately effective in vitro against clinical isolates of P. aeruginosa. Reports from this country have confirmed the moderate in-vitro susceptibility of strains of

Microbial Isolates from Patients and their Antibiogram at the Tertiary Care Burn Unit in Bangladesh

Infection and antibacterial resistance are important issue in severe burn. This prospective study was carried out in 112 patients who were enrolled from July 2007 to June 2008 in DMCH burn unit (only dedicated burn facility in Bangladesh with a mean annual admission of 869). The aim of this study were to investigate the profile of microorganism and resistance to antimicrobial agents; individuals who were admitted more than 5 days, with partial or full thickness burn developed clinical signs and symptoms of wound infection or pneumonia or septicaemia were included in this study. Nearly 50% of participants were aged 11-30 yrs, the most common type of burn was flame burn and females were the common victims. Bacterial isolates were found in 104 (92.85%) samples and eight (08) swabs were sterile (7.14%). Pseudomonas species was the commonest pathogens (46.42%) followed by Proteus species (21.41%) and Klebsiella species (19.6%). Multiple organisms were found in 38 samples(33.92%). Antibiogram results obtained from ten antimicrobial agents demonstrated that Imipenem was the most efective agent, followed by amikacin and ceftazidime (92.3%, 52.8% and 38.46% sensitive respectively). Hundred percent (100%) of Proteus species were sensitive to imipenem, then amikacin 58.33%; they were highly resistant to cephalosporins (nearly 100%) and ciprofloxacin (83.33%). The resistance of Pseudomonas aeruginosa to anti-pseudomonas agents were exceptionally high. Newer drugs were found to be effective. DOI: http://dx.doi.org/10.3329/jbcps.v29i2.7949 (J Bangladesh Coll Phys Surg 2011; 29: 62-66)