Aerobic Gram-negative Bacteria Research Articles

Bacterial contamination of hemodialysis water in three randomly selected centers in South Western Nigeria.

Hemodialysis (HD) is the most common method of renal replacement therapy for patients with either acute kidney injury in the failure stage or end stage kidney failure in Nigeria. The number of dialysis centers in Nigeria has risen exponentially from 10 centers two decades ago to more than 120 centers in 2015. The number of patients needing renal replacement therapy in the country in the form of HD has also risen close to a projected 2000/year. The outcome from HD in Nigeria is poor as a result of a myriad of interwoven factors such as complications of cardiovascular diseases and suboptimal dialysis dose primarily due to economic factors. These are often complicated by episodes of dialysis water related bacteremia, possibly as a result of the apparent lack of a standardized guideline or protocol for monitoring dialysis water treatment system which is the driving force of dialysis units. This is a multicenter laboratory-based study designed to determine the microbiological quality of samples of HD water and dialysate in randomly selected dialysis units in three major government teaching hospitals in Nigeria. Water samples were aseptically and serially collected from three HD units. The samples were taken from 6 points at each center coded A, B, and C over a 6-month period. The water system in the three dialysis centers were grossly contaminated with Gram-negative aerobic bacteria such as Pseudomonas species and Moraxella species at all the points in the three centers. Conventionally, water treatment is a major determinant of morbidity and mortality in HD units, and the microbial quality is a major factor involved. There is evidence of bacterial contamination in the dialysis units sampled in this study. There is thus the compelling need for periodic microbiological monitoring of water after each treatment step. A uniform national guideline as part of an effective quality assurance protocol in infection surveillance is also advocated for dialysis units in Nigeria.

Spontaneous Bacterial Peritonitis: Is It Still A Life-Threatening Issue in Cirrhosis?

Spontaneous bacterial peritonitis is the commonest and a deadly complication of cirrhosis that happens in 10% to 30% of patients admitted to hospital. The main mechanism that is being associated with its occurrence are bacterial overgrowth with translocation through the increased permeable small intestinal wall and impaired immune defense. The Gram-negative aerobic bacteria are the major pathogens responsible for SBP episodes although Gram-positive bacteria are being considered emergent agents. The ready diagnosis of SBP is a key factor for the decrease in mortality rates observed in recent years. The medical diagnosis is neither sensitive nor specific and the search for new useful and available tools to make it quicker is an important endpoint of current studies. The use of empirical antibiotics, mainly cefotaxime, improves significantly the short-term prognosis of patients with SBP. The recurrence rate is high and antibiotic prophylaxis has been recommended in high-risk scenarios. Unfortunately, the long-term prognosis remains poor.

Use of rifaximin in gastrointestinal and liver diseases.

Rifaximin is a broad spectrum oral antibiotic with antimicrobial activity against Gram-positive and Gram-negative aerobic and anaerobic bacteria. It is poorly absorbed and thus has a highly favorable safety profile. Rifaximin has been shown to be effective in the treatment of traveler's diarrhea, functional bloating and irritable bowel syndrome, small bowel bacterial overgrowth and in the prevention of recurrent overt hepatic encephalopathy. In addition, there is emerging evidence for a possible beneficial effect of rifaximin in the treatment of uncomplicated diverticular disease and in the prevention of recurrent diverticulitis. The use of rifaximin is associated with a low incidence of development, or persistence of spontaneous bacterial mutants. Moreover, the development of important drug resistance among extra-intestinal flora during rifaximin therapy is unlikely because of minimal systemic absorption and limited cross-resistance of rifaximin with other antimicrobials. This review addresses the current and emerging role of rifaximin in the treatment of gastrointestinal and liver disorders.

Preparation of Thermosensitive Gel for Controlled Release of Levofloxacin and Their Application in the Treatment of Multidrug-Resistant Bacteria.

Levofloxacin is a synthetic broad-spectrum antibacterial agent for oral or intravenous administration. Chemically, levofloxacin is the levorotatory isomer (L-isomer) of racemate ofloxacin, a fluoroquinolone antibacterial agent. Quinolone derivatives rapidly and specifically inhibit the synthesis of bacterial DNA. Levofloxacin has in vitro activity against a broad range of aerobic and anaerobic Gram-positive and Gram-negative bacteria. However, formulation of combined poloxamers thermoregulated (as Pluronic® F127) and levofloxacin for use in multiresistant bacterial treatment were poorly described in the current literature. Thus, the aim of the present work is to characterize poloxamers for levofloxacin controlled release and their use in the treatment of multidrug bacterial resistance. Micelles were produced in colloidal dispersions, with a diameter between 5 and 100 nm, which form spontaneously from amphiphilic molecules under certain conditions as concentration and temperature. Encapsulation of levofloxacin into nanospheres showed efficiency and enhancement of antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae when compared with only levofloxacin. Furthermore, all formulations were not cytotoxic for NIH/3T3 cell lineage. In conclusion, poloxamers combined with levofloxacin have shown promising results, better than alone, decreasing the minimal inhibitory concentration of the studied bacterial multiresistance strains. In the future, this new formulation will be used after being tested in animal models in patients with resistant bacterial strains.

Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation.

Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gram-negative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination (SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients.

Direct Identification of Aerobic Bacteria by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry Is Accurate and Robust.

Bacterial identification in the clinical laboratory can be laborious and expensive. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid and cost-effective diagnostic tool for the identification of organisms routinely found in the microbiology laboratory. The objective of this study was to demonstrate that identification of aerobic Gram-positive and Gram-negative organisms could be performed accurately and efficiently by MALDI-TOF MS and the Bruker Biotyper system without the use of time-consuming extraction methodologies. Isolates previously recovered by routine culture and workup from clinical specimens were cultured to appropriate media, identified directly by MALDI-TOF MS, and compared to results from various biochemical identification methods. Using the direct-smear method, 99.5% and 98.0% of aerobic Gram-negative and Gram-positive bacteria, respectively, were identified to the genus level. At a score of ≥1.9, 97.6% Gram-negative organisms and 94.6% Gram-positive organisms were correctly identified to the species level by direct-smear method. Only 1.1% of isolates required further reflex to direct-plate extraction. The direct-smear method proved to be robust, as various growth temperatures, media, culture age, and different operators had no notable impact on the bacterial identification rate. The direct-smear method is an accurate and time-saving method for routine species-level bacterial identification.

Comparing different methods used to collect material for a microbiological evaluation of patients with chronic rhinosinusitis

There is still controversy on which is the best method to collect the secretion directly from the middle meatus or maxillary sinus in patients with chronic rhinosinusitis.Aim: To evaluate the prevalence of bacteria in patients with chronic rhinosinusitis and compare the suction trap collector to direct aspiration attached to a syringe for the microbiological analysis of these secretions.Materials and Methods: Prospective study involving 31 patients who underwent endoscopically guided maxillary secretion aspiration by two different methods (aspiration with the collector tube “suction trap” and aspiration with the use of a catheter connected to a syringe), to determine the microbiological diagnosis and to compare the two methods used.Results: microorganisms grew samples collected from 55% of the 31 patients. The most frequent bacteria were S. aureus, Pseudomonas aeruginosa and other aerobic Gram-negative bacteria. The results from cultures were similar between the two methods in 71% of patients.Conclusion: S. aureus, Pseudomonas aeruginosa and other aerobic Gram-negative bacteria make up the main flora in the maxillary sinus of the patients. There was good correlation between the microbiological results obtained by using a catheter attached to a syringe and the “suction trap” nasal collector.

Engineered microparticles based on drug–polymer coprecipitates for ocular-controlled delivery of Ciprofloxacin: influence of technological parameters

Ciprofloxacin is a drug active against a broad spectrum of aerobic Gram-positive and Gram-negative bacteria, for the therapy of ocular infections. It requires frequent administrations owing to rapid ocular clearance and it is a good candidate for ocular controlled release formulations. The preparation of such drug release systems is still a challenge. Ionic interactions between ciprofloxacin and the polyelectrolytes chondroitin sulfate or lambda carrageenan result in coprecipitates that can act as microparticulate controlled release systems from which the drug is released after being displaced by the medium’s ions. In some formulations, Carbopol was added to improve the mucoadhesive properties. The aim of this research was the study of the influence of the technological parameters of the preparation method of coprecipitates on their particle size, with the goal of achieving particles engineered with a size suitable for the ocular administration. Technological parameters taken into account were: concentration of drug and polymer solutions utilized for the preparation of interaction products, possible use of surfactants (kind and concentration), temperature of the solutions and stirring during the process of preparation of the coprecipitates. Preliminary stability study tests were carried out to further characterize the leader formulation. Particle size in suspensions for ocular drug delivery is a critical parameter influencing the quality of the formulation. The results obtained from this study show that chondroitin sulfate coprecipitates present the best characteristics in terms of particle size suitable for ocular administration. A further improvement of the particle size characteristics has been obtained with the addition of surfactants.

Burn Injury Alters the Intestinal Microbiome and Increases Gut Permeability and Bacterial Translocation.

Sepsis remains one of the leading causes of death in burn patients who survive the initial insult of injury. Disruption of the intestinal epithelial barrier has been shown after burn injury; this can lead to the translocation of bacteria or their products (e.g., endotoxin) from the intestinal lumen to the circulation, thereby increasing the risk for sepsis in immunocompromised individuals. Since the maintenance of the epithelial barrier is largely dependent on the intestinal microbiota, we examined the diversity of the intestinal microbiome of severely burned patients and a controlled mouse model of burn injury. We show that burn injury induces a dramatic dysbiosis of the intestinal microbiome of both humans and mice and allows for similar overgrowths of Gram-negative aerobic bacteria. Furthermore, we show that the bacteria increasing in abundance have the potential to translocate to extra-intestinal sites. This study provides an insight into how the diversity of the intestinal microbiome changes after burn injury and some of the consequences these gut bacteria can have in the host.

Methylopila turkiensis sp. nov., a new aerobic facultatively methylotrophic phytosymbiont

A new facultative methylotroph, strain Side1T, was isolated from the phyllosphere of Bougainvillea sp. L. The isolate is represented by rod-shaped, aerobic gram-negative asporogenous bacteria which divide by binary fission. Methanol and mono- and trimethylamine were utilized, as well as a limited spectrum of polycarbon substrates, while methane and dichloromethane were not used. Growth occurred at pH 6.0–9.0 with the optimum at pH 7.0 within the temperature range from 20 to 40°C (optimum at 28–30°C) and 0–2.5% NaCl in the medium. The predominant fatty acids were cis-11-octadecenoic (C18:1ω7c), 11-methyl-octadecenoic (C18:ω7c11Me), and stearic (C18:0) acids. Phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, and diphosphatidylglycerol were the dominant phospholipids. Q10 was the dominant ubiquinone. The isolate oxidized methanol and methylamine by the appropriate dehydrogenases. The isocitrate lyase-negative variant of the serine pathway was used. Ammonium assimilation involved glutamate dehydrogenase and the glutamate cycle (glutamate synthase and glutamine synthetase). The strain synthesized indole and siderophores; it solubilized insoluble phosphates. The DNA G+C content (Tm) was 65.4 mol %. While the nucleotide sequence of the 16S rRNA gene of strain Side1 exhibited high similarity to those of Methylopila species (M. musalis MUSAT and M. capsulata IM1T), DNA-DNA homology with these cultures was 32–37%. The results obtained supported classification of strain Side1T as a new species Methylopila turkiensis sp. nov. (VKM B-2748T= DSM 27566T).

Draft Genome Sequence of Cellulophaga sp. E6, a Marine Algal Epibiont That Produces a Quorum-Sensing Inhibitory Compound Active against Pseudomonas aeruginosa.

The genus Cellulophaga is composed of obligate aerobic Gram-negative bacteria commonly found in association with marine algae. We report the approximately 4.42-Mbp draft genome sequence of Cellulophaga sp. E6, which inhibits N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL)–mediated quorum sensing (QS), lasB transcription, and biofilm formation by Pseudomonas aeruginosa.

Prevalence and Antibiotic Susceptibility of Gram-negative Aerobic Bacteria Cultured from the Intestine and Hepatopancreas of Blue Land Crab (Cardisoma guanhumi) in Grenada, West Indies

Aim: To evaluate the prevalence of aerobic bacteria associated with the intestine and hepatopancreas of blue land crab and the susceptibility of the bacteria to a panel of antimicrobials that included some drugs used for the treatment of bacterial infections in the human and veterinary clinics in Grenada. Study Design: The tested crabs were collected during a three month period from November 2011 to February 2012 from six parishes of Grenada and analyzed in the bacteriology lab in the

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Nanotechnology has offered enormous improvement in field of therapeutics by means of designing of nano-carriers that can cross biological barriers and are able to target cellular reservoirs. The aim of the present investigation was to formulate and evaluate Niosomes, a synthetic microscopic non-ionic surfactant vesicles formed on the admixture of a non-ionic surfactant, cholesterol and phosphate with subsequent hydration in aqueous media. The delivery of drugs by “vesicular drug delivery system” such as niosomes provides several important advantages over conventional drug therapy. Ofloxacin was selected as a suitable drug for the present study because it is a potent secondgeneration fluoroquinolone active against a broad range of gram positive and gram-negative aerobic and anaerobic bacteria. In the present investigation three formulations of Niosomal drug delivery system of ofloxacin with non ionic surfactant, span 60, in various proportions were prepared and evaluated for Morphological characterization, Encapsulation efficiency, In-vitro drug release study. The Ofloxacin niosomes were prepared by lipid film hydration method. The prepared ofloxacin niosomes showed a vesicle size of 100-300 nm, the entrapment efficiency was 78.4%. The partition coefficient value of ofloxacin was found to be 0.5.

Antimicrobial susceptibility of clinically isolated anaerobic bacteria in a University Hospital Centre Split, Croatia in 2013

Anaerobic bacteria play a significant role in many endogenous polymicrobial infections. Since antimicrobial resistance among anaerobes has increased worldwide, it is useful to provide local susceptibility data to guide empirical therapy. The present study reports recent data on the susceptibility of clinically relevant anaerobes in a University Hospital Centre (UHC) Split, Croatia.A total of 63 Gram-negative and 59 Gram-positive anaerobic clinical isolates from various body sites were consecutively collected from January to December 2013. Antimicrobial susceptibility testing was performed using standardized methods and interpreted using EUCAST criteria. Patient's clinical and demographic data were recorded by clinical microbiologist.Among 35 isolates of Bacteroides spp., 97.1% were resistant to penicillin (PCN), 5.7% to amoxicillin/clavulanic acid (AMC), 8.6% to piperacillin/tazobactam (TZP), 29.0% to clindamycin (CLI) and 2.9% to metronidazole (MZ). Percentages of susceptible strains to imipenem (IPM), meropenem (MEM) and ertapenem (ETP) were 94.3. Resistance of other Gram-negative bacilli was 76.0% to PCN, 8.0% to AMC, 12.0% to TZP, 28.0% to CLI and 8% to MZ. All other Gram-negative strains were fully susceptible to MEM and ETP, while 96.0% were susceptible to IPM. Clostridium spp. isolates were 100% susceptible to all tested antibiotics except to CLI (two of four tested isolates were resistant). Propionibacterium spp. showed resistance to CLI in 4.3%, while 100% were resistant to MZ. Among other Gram-positive bacilli, 18.2% were resistant to PCN, 9.1% to CLI and 54.5% to MZ, while 81.8% of isolates were susceptible to carbapenems. Gram-positive cocci were 100% susceptible to all tested antimicrobials except to MZ, where 28.6% of resistant strains were recorded.Abdomen was the most common source of isolates (82.5%). The most prevalent types of infection were abscess (22.1%), sepsis (14.8%), appendicitis (13.9%) and peritonitis (6.6%).Twenty four patients (19.7%) received empiric antimicrobial therapy. One hundred and one patients (82.8%) had polymicrobial aerobic/anaerobic isolates cultivated from the same specimens. Almost all aerobic bacteria were of endogenous origin and showed fully susceptible antimicrobial profile; only 8.7% (9/104) were multiresistant and considered as hospital acquired.Based on our findings, β-lactam/β-lactamase inhibitor combinations and metronidazole remain useful antimicrobials for empiric treatment of anaerobic infections, while carbapenems should be reserved for situations were multidrug resistant, aerobic or facultative Gram-negative bacteria are expected. However, a certain percentage of resistant isolates were observed for each of these agents. Therefore, periodic resistance surveillance in anaerobes is highly recommended in order to guide empirical therapy.

The microbiology of chronic rhinosinusitis with and without nasal polyps

Conclusion: Staphylococcus aureus, Streptococcus, Haemophilus, Enterobacter, and Corynebacterium appear to be more frequently associated with patients with chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) than with patients with CRS without nasal polyps (CRSsNP) or control subjects. Furthermore, the isolation rate of Staphylococcus aureus appears to be much lower in Chinese CRSwNP patients compared with their caucasian counterparts. Objectives: To compare the predominant bacteriologic profiles in middle meatus of patients with CRSwNP, those with CRSsNP, and control subjects. Methods: A total of 165 CRSwNP patients, 76 CRSsNP patients, and 44 control subjects were recruited into the study. Swab samples were obtained from the middle meatus during endoscopic sinus surgery and processed for the presence of aerobic and non-aerobic bacteria and fungi. Results: Mostly aerobic and facultative anaerobic bacteria were detected in the samples from all three study groups, of which the most common aerobic bacteria were coagulase-negative staphylococci, Corynebacterium species, Staphylococcus aureus, and Haemophilus influenzae. In contrast, comparatively few anaerobic bacteria and fungi were isolated from the three study groups. In CRSwNP patients, significantly more Gram-negative aerobic and facultative anaerobic bacteria were isolated from the subgroup with normal eosinophil numbers than from the subgroup with increased blood eosinophils (p = 0.005). Correspondence analysis showed coagulase-negative staphylococci to be closely associated with all three patient groups, whereas Staphylococcus aureus, Streptococcus, Haemophilus, Enterobacter, and Corynebacterium species were associated with CRSwNP patients.

Microbial pathogens in moderate to severe diabetic foot infections

Foot infections are the most common complications in diabetic patients and common cause of morbidity and mortality. They require prompt diagnosis and involvement of a multidisciplinary team in their treatment. Prospective study to define the etiology of the deep diabetic foot infections and its specific characteristics concerning the adequate empiric antimicrobial therapy was done. The study included 50 patients, who underwent minor amputations due to moderate to severe infection of the foot. All specimens for microbiology testing were taken by biopsy or aspiration during surgery. Specimens cultivation, identification of the isolated microorganisms and their susceptibility towards antimicrobial agents were performed by conventional methods and automated systems. Diabetic foot infections were predominantly polymicrobial; 42 (84%) of the cases, caused by associations between two, three and four different pathogens. Mixed infections caused by aerobic and anaerobic bacteria were found in 17 patients (34%). Gram-positive bacteria were the prominent microbial pathogens in both monobacterial and polymicrobial infection; mostly Streptococcus agalactiae and Staphylococcus aureus. Gram-negative aerobic bacteria presented 33.3% of all isolated bacteria, predominantly members of Enterobacteriaceae family. Obligate anaerobes represents 16.66% of all isolated bacteria and were causative organisms in 17 (34%) of the patients, more than the other Bacteroides fragilis group and anaerobic streptococci. The strains isolated were susceptible to the recommended antibacterial agents for treatment of moderate and severe diabetic foot infections (DFIs). The optimal approach to DFIs requires immediate surgical intervention, revascularization in the setting of a multisegment vascular lesions, microbiological examination of suitable clinical materials and appropriate antibacterial therapy for empiric treatment of aerobic and anaerobic pathogens Key words: Diabetic foot, infection, microbial pathogens.

Biliary endoprosthesis: a prospective analysis of bacterial colonization and risk factors for sludge formation.

Bacterial colonization of biliary stents is one of the driving forces behind sludge formation which may result in stent occlusion. Major focus of the study was to analyze the spectrum and number of microorganisms in relation to the indwelling time of stents and the risk factors for sludge formation. 343 stents were sonicated to optimize the bacterial release from the biofilm and identified by matrix-associated laser desorption/ionization-time of flight mass spectrometer (MALDI-TOF). 2283 bacteria were analyzed in total. The most prevalent microorganisms were Enterococcus species (spp.) (504;22%), followed by Klebsiella spp. (218;10%) and Candida spp. (188;8%). Colonization of the stents mainly began with aerobic gram-positive bacteria (43/49;88%) and Candida spp. (25/49;51%), whereas stents with an indwelling time>60 days(d) showed an almost equal colonization rate by aerobic gram-negative (176/184;96%) and aerobic gram-positive bacteria (183/184;99%) and a high proportion of anaerobes (127/184;69%). Compared to stents without sludge, more Clostridium spp. [(P = 0.02; Odds Ratio (OR): 2.4; 95% confidence interval (95%CI): (1.1–4.9)]) and Staphylococcus spp. [(P = 0.03; OR (95%CI): 4.3 (1.1–16.5)] were cultured from stents with sludge. Multivariate analysis revealed a significant relationship between the number of microorganisms [P<0.01; OR (95%CI): 1.3(1.1–1.5)], the indwelling time [P<0.01; 1–15 d vs. 20–59 d: OR (95%CI): 5.6(1.4–22), 1–15 d vs. 60–3087 d: OR (95% CI): 9.5(2.5–35.7)], the presence of sideholes [P<0.01; OR (95%CI): 3.5(1.6–7.9)] and the occurrence of sludge. Stent occlusion was found in 70/343(20%) stents. In 35% of cases, stent occlusion resulted in a cholangitis or cholestasis. In conclusion, microbial colonization of the stents changed with the indwelling time. Sludge was associated with an altered spectrum and an increasing number of microorganisms, a long indwelling time and the presence of sideholes. Interestingly, stent occlusion did not necessarily lead to a symptomatic biliary obstruction.

Dissipation of phenanthrene and pyrene at the aerobic-anaerobic soil interface: differentiation induced by the rhizosphere of PAH-tolerant and PAH-sensitive rice (Oryza sativa L.) cultivars.

A pot experiment was conducted to reveal the removal of two polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, PHE, and pyrene, PYR) during rice cultivation in a paddy field. The rhizosphere effect on facilitating dissipation of PAHs varied simultaneously as a function of soil properties, PAH types, cultivation time, and genotypes within rice cultivars, with differences performed for PYR but not PHE. Changes in soil PLFA profiles evidenced that the growth of rice roots modified the dominant species within rhizosphere microbial communities and induced a selective enrichment of Gram-negative aerobic bacteria capable of degrading, thereby resulting in the differentiated dissipation of PYR. While the insignificant differences in PHE dissipation might be attributed to its higher solubility and availability under flooded condition that concealed the differences in improvement of bioavailability for microorganisms between rhizosphere and non-rhizosphere, and between both soils and both rice cultivars. Our findings illustrate that the removal of PAHs in paddy soils was more complex relative to those in dryland soils. This was possibly due to the specialty of rice roots for oxygen secretion that provides development of redox heterogeneous microbial habitats at root-soil interface under flooded condition.

Efficacy and safety of nadifloxacin for bacterial skin infections: results from clinical and post-marketing studies.

IntroductionSkin and soft tissue infections involve microbial invasion of the skin and underlying soft tissues and are estimated to affect 7–10% of hospitalized patients worldwide. Nadifloxacin, a topical fluoroquinolone, has been shown to be effective against aerobic Gram-negative, Gram-positive (including MRSA and coagulase-negative staphylococci), and anaerobic bacteria. However, there is paucity of data comparing efficacy and safety of 1% nadifloxacin with other anti-bacterials for skin infections in Indian patients.MethodsThis article presents the results of one post-marketing surveillance (PMS) and three randomized, open, non-blinded, multi-centric clinical studies that compared nadifloxacin with mupirocin and framycetin, and nadifloxacin with fusidic acid. Patients in India, aged from 1 to 65 years old, suffering from mild to moderate bacterial skin infections including impetigo, secondarily infected wounds, folliculitis, infected atopic dermatitis, and furunculosis were randomly allocated to three treatment groups within the studies. Efficacy was assessed by the evaluation of symptoms of erythema, exudation, swelling, pruritus, crusting, pain and tenderness in all the studies.ResultsA total of 272 subjects were enrolled in the study and subjects were randomly assigned to one of the three treatment groups; 92 in the nadifloxacin group, 90 in the mupirocin group, and 90 in the framycetin group. A significant reduction in the mean scores for bacterial infection symptoms in the nadifloxacin groups was observed when compared to mupirocin, framycetin and fusidic acid groups. Both physician and patients rated nadifloxacin as excellent (complete remission of symptoms) on a 4-point scale in the studies. No adverse events (AEs) were reported in the clinical studies. In the PMS, only two patients (of 329, 0.6%) reported AEs including burning and itching, one in each patient that had resolved at the time of reporting.ConclusionNadifloxacin, a fluoroquinolone, is a new alternative topical agent in the treatment of bacterial skin infection with minimal AEs.Electronic supplementary materialThe online version of this article (doi:10.1007/s13555-014-0062-1) contains supplementary material, which is available to authorized users.

Antimicrobial susceptibility and extended-spectrum beta-lactamase rates in aerobic gram-negative bacteria causing intra-abdominal infections in Vietnam: report from the Study for Monitoring Antimicrobial Resistance Trends (SMART 2009–2011)

Treatment options for multidrug-resistant pathogens remain problematic in many regions and individual countries, warranting ongoing surveillance and analysis. Limited antimicrobial susceptibility information is available for pathogens from Vietnam. This study determined the bacterial susceptibility of aerobic gram-negative pathogens of intra-abdominal infections among patients in Vietnam during 2009–2011. A total of 905 isolates were collected from 4 medical centers in this investigation as part of the Study for Monitoring Antimicrobial Resistance Trends. Antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL) rates among the appropriate species were determined by a central laboratory using Clinical and Laboratory Standards Institute methods. Among the species collected, Escherichia coli (48.1% ESBL-positive) and Klebsiella pneumoniae (39.5% ESBL-positive) represented the majority (46.4%) of the isolates submitted for this study. Ertapenem MIC90 values were lowest for these 2 species at 0.12 and 0.25μg/mL and remained unchanged for ESBL-positive isolates. Imipenem MIC90 values were also the same for all isolates and ESBL-positive strains at 0.25 and 0.5μg/mL, respectively. Ertapenem MIC90 values for additional species with sufficient numbers for analysis, including Enterobacter cloacae, Proteus mirabilis, Acinetobacter baumannii, and Pseudomonas aeruginosa, were 1, 0.06, >4, and >4μg/mL, respectively. Analysis of beta-lactamases in a subset of 132 phenotypically ESBL-positive Enterobacteriaceae demonstrated that CTX-M variants, particularly CTX-M-27 and CTX-M-15, were the predominant enzymes. High resistance rates in Vietnam hospitals dictate continuous monitoring as antimicrobial inactivating enzymes continue to spread throughout Asia and globally.