Long-Term Succession Shows Interspecies Competition of Geobacter in Exoelectrogenic Biofilms.

Geobacter spp. are well-known exoelectrogenic microorganisms that often predominate acetate-fed biofilms in microbial fuel cells (MFCs) and other bioelectrochemical systems (BESs). By using an amplicon sequence variance analysis (at one nucleotide resolution), we observed a succession between two closely related species (98% similarity in 16S RNA), Geobacter sulfurreducens and Geobacter anodireducens, in the long-term studies (20 months) of MFC biofilms. Geobacter spp. predominated in the near-electrode portion of the biofilm, while the outer layer contained an abundance of aerobes, which may have helped to consume oxygen but reduced the relative abundance of Geobacter. Removal of the outer aerobes by norspermidine washing of biofilms revealed a transition from G. sulfurreducens to G. anodireducens. This succession was also found to occur rapidly in co-cultures in BES tests even in the absence of oxygen, suggesting that oxygen was not a critical factor. G. sulfurreducens likely dominated in early biofilms by its relatively larger cell size and production of extracellular polymeric substances (individual advantages), while G. anodireducens later predominated due to greater cell numbers (quantitative advantage). Our findings revealed the interspecies competition in the long-term evolution of Geobacter genus, providing microscopic insights into Geobacter's niche and competitiveness in complex electroactive microbial consortia.

Differential effects of inappropriate empirical antibiotic therapy in adults with community-onset gram-positive and gram-negative aerobe bacteremia.

Bacteremia is associated with high morbidity and mortality, which contribute substantially to health care costs. A beneficial influence of appropriate empirical antimicrobial therapy (EAT) on patient outcome is evidenced; However, the evidence highlighting a comparison of clinical manifestations and of the effects of inappropriate EAT between Gram-positive and Gram-negative bacteremia is insufficient. In a retrospective 6-year cohort study, the total 2053 adults (Gram-positive, 566; Gram-negative 1487) presenting with community-onset monomicrobial aerobes bacteremia were recruited. Inappropriate EAT was defined as the first dose of an appropriate antimicrobial agent not being administered within the first 24 h after blood cultures were drawn. Although the bacteremia severity (a Pitt bacteremia score) at onset, comorbidity severity (the McCabe-Johnson classification), and 28-day mortality rate were similar in the two groups. Furthermore, after adjustment of independent predictors of 28-day mortality respectively recognized by the multivariate regression model in Gram-negative and Gram-positive groups, the Kaplan-Meier curve and Cox regression analysis revealed a significant difference (adjust odds ratio [AOR], 2.68; P < 0.001) between appropriate and inappropriate EAT in the Gram-negative group, but not in the Gram-positive group (AOR, 1.54; P = 0.06). Conclusively, patients with Gram-positive and Gram-negative bacteremia exhibited the similar presentation in bacteremia severity, but a greater impact of inappropriate EAT on survival of patients with Gram-negative aerobe bacteremia was evidenced.

RubisCO Early Oxygenase Activity: A Kinetic and Evolutionary Perspective.

RubisCO (D-ribulose 1,5-bisphosphate carboxylase/oxygenase) is Earth's main enzyme responsible for CO2 fixation via carboxylation of ribulose-1,5-bisphosphate (RuBP) into organic matter. Besides the carboxylation reaction, RubisCO also catalyzes the oxygenation of RuBP by O2 , which is probably as old as its carboxylation properties. Based on molecular phylogeny, the occurrence of the reactive oxygen species (ROS)-removing system and kinetic properties of different RubisCO forms, we postulated that RubisCO oxygenase activity appeared in local microoxic areas, yet before the appearance of oxygenic photosynthesis. Here, in reviewing the literature, we present a novel hypothesis: the RubisCO early oxygenase activity hypothesis. This hypothesis may be compared with the exaptation hypothesis, according to which latent RubisCO oxygenase properties emerged later during the oxygenation of the Earth's atmosphere. The reconstruction of ancestral RubisCO forms using ancestral sequence reconstruction (ASR) techniques, as a promising way for testing of RubisCO early oxygenase activity hypothesis, is presented.

Bacterial diversity obtained by culturable approaches in the gut of Glossina pallidipes population from a non sleeping sickness focus in Tanzania: preliminary results.

BACKGROUND: Glossina pallidipes is a haematophagous insect that serves as a cyclic transmitter of trypanosomes causing African Trypanosomiasis (AT). To fully assess the role of G. pallidipes in the epidemiology of AT, especially the human form of the disease (HAT), it is essential to know the microbial diversity inhabiting the gut of natural fly populations. This study aimed to examine the diversity of G. pallidipes fly gut bacteria by culture-dependent approaches. RESULTS: 113 bacterial isolates were obtained from aerobic and anaerobic microorganisms originating from the gut of G. pallidipes. 16S rDNA of each isolate was PCR amplified and sequenced. The overall majority of identified bacteria belonged in descending order to the Firmicutes (86.6%), Actinobacteria (7.6%), Proteobacteria (5.5%)and Bacteroidetes (0.3%). Diversity of Firmicutes was found higher when enrichments and isolation were performed under anaerobic conditions than aerobic ones. Experiments conducted in the absence of oxygen (anaerobiosis) led to the isolation of bacteria pertaining to four phyla (83% Firmicutes, 15% Actinobacteria, 1% Proteobacteria and 0.5% Bacteroidetes, whereas those conducted in the presence of oxygen (aerobiosis) led to the isolation of bacteria affiliated to two phyla only (90% Firmicutes and 10% Proteobacteria). Phylogenetic analyses placed these isolates into 11 genera namely Bacillus, Acinetobacter, Mesorhizobium, Paracoccus, Microbacterium, Micrococcus, Arthrobacter, Corynobacterium, Curtobacterium, Vagococcus and Dietzia spp.which are known to be either facultative anaerobes, aerobes, or even microaerobes. CONCLUSION: This study shows that G. pallidipes fly gut is an environmental reservoir for a vast number of bacterial species, which are likely to be important for ecological microbial well being of the fly and possibly on differing vectorial competence and refractoriness against AT epidemiology.

Vaginal ecosystem modeling of growth patterns of anaerobic bacteria in microaerophilic conditions.

The human vagina constitutes a complex ecosystem created through relationships established between host mucosa and bacterial communities. In this ecosystem, classically defined bacterial aerobes and anaerobes thrive as communities in the microaerophilic environment. Levels of CO2 and O2 present in the vaginal lumen are impacted by both the ecosystem's physiology and the behavior and health of the human host. Study of such complex relationships requires controlled and reproducible causational approaches that are not possible in the human host that, until recently, was the only place these bacterial communities thrived. To address this need we have utilized our ex vivo human vaginal mucosa culture system to support controlled, reproducible colonization by vaginal bacterial communities (VBC) collected from healthy, asymptomatic donors. Parallel vaginal epithelial cells (VEC)-VBC co-cultures were exposed to two different atmospheric conditions to study the impact of CO2 concentrations upon the anaerobic bacteria associated with dysbiosis and inflammation. Our data suggest that in the context of transplanted VBC, increased CO2 favored specific lactobacilli species defined as microaerophiles when grown as monocultures. In preliminary studies, the observed community changes also led to shifts in host VEC phenotypes with significant changes in the host transcriptome, including altered expression of select molecular transporter genes. These findings support the need for additional study of the environmental changes associated with behavior and health upon the symbiotic and adversarial relationships that are formed in microbial communities present in the human vaginal ecosystem.

Aerobic Microbiological Spectrum and Antibiotic Resistance in Children Operated for Anorectal Abscesses.

(1) Background: Anorectal abscesses are a relatively rare pathology in childhood. Most often, male children under 1 year of age are affected. The importance of microbiological examination for the diagnosis and treatment of such patients remains debatable among surgeons, resulting in scarce data being available in the literature. We aimed to identify the aerobic microbiological spectrum and antibiotic resistance of isolates in children undergoing operation to treat anorectal abscesses. (2) Methods: We performed a case series of 102 children diagnosed and operated for anorectal abscesses over a period of 10 years (2010-2019). Purulent wound exudate was used for microbiological evaluation, which was subsequently cultured on 5% sheep-blood agar and eosin-methylene blue agar. For microbiological identification, conventional biochemical tests and semi-automated (API 20, bioMerieux, Marcy-l'Étoile, France) tests were used, as well as automated systems (Vitek-2 Compact, bioMerieux, France). Antimicrobial susceptibility testing was performed by the disk diffusion method of Bauer-Kirby and by determining the minimal inhibitory concentrations for glycopeptides. The results were interpreted according to the EUCAST standard for the corresponding year. (3) Results: Microbiological testing in children operated for anorectal abscesses mainly identified the gut commensals that normally reside in the rectal mucosa. Monocultures were found in just over half of the cases. Escherichia coli, Klebsiella pneumoniae complex, and Proteus mirabilis were the most frequently isolated. In addition, Staphylococcus aureus was found in 7% of patients. In Gram-negative bacteria, antibiotic resistance was most often observed in penicillins, cephalosporins, sulfonamides, and fluoroquinolones. (4) Conclusions: The increasing rates of antimicrobial resistance impose the need for the local monitoring of circulating commensal bacteria associated with anorectal abscesses in children to guide antibiotic therapy when indicated.

The radical impact of oxygen on prokaryotic evolution-enzyme inhibition first, uninhibited essential biosyntheses second, aerobic respiration third.

Molecular oxygen is a stable diradical. All O2-dependent enzymes employ a radical mechanism. Generated by cyanobacteria, O2 started accumulating on Earth 2.4 billion years ago. Its evolutionary impact is traditionally sought in respiration and energy yield. We mapped 365 O2-dependent enzymatic reactions of prokaryotes to phylogenies for the corresponding 792 protein families. The main physiological adaptations imparted by O2-dependent enzymes were not energy conservation, but novel organic substrate oxidations and O2-dependent, hence O2-tolerant, alternative pathways for O2-inhibited reactions. Oxygen-dependent enzymes evolved in ancestrally anaerobic pathways for essential cofactor biosynthesis including NAD+, pyridoxal, thiamine, ubiquinone, cobalamin, heme, and chlorophyll. These innovations allowed prokaryotes to synthesize essential cofactors in O2-containing environments, a prerequisite for the later emergence of aerobic respiratory chains.

Remedial trial of sequential anoxic/oxic chemico-biological treatment for decontamination of extreme hexachlorocyclohexane concentrations in polluted soil.

During production of γ-hexachlorocyclohexane (γ-HCH), thousands of tons of other isomers were synthesized as byproducts, and after dumping represent sources of contamination for the environment. Several microbes have the potential for aerobic and anaerobic degradation of HCHs, and zero-valent iron is an effective remediation agent for abiotic dechlorination of HCHs, whereas the combination of the processes has not yet been explored. In this study, a sequence of anoxic/oxic chemico-biological treatments for the degradation of HCHs in a real extremely contaminated soil (10-30 g/kg) was applied. Approximately 1500 kg of the soil was employed, and various combinations of reducing and oxygen-releasing chemicals were used for setting up the aerobic and anaerobic phases. The best results were obtained with mZVI/nZVI, grass cuttings, and oxygen-releasing compounds. In this case, 80 % removal of HCHs was achieved in 129 days, and 98 % degradation was achieved after 1106 days. The analysis of HCHs and their transformation products proved active degradation when slight accumulation of the transformation product during the anaerobic phase was followed by aerobic degradation. The results document that switching between aerobic and anaerobic phases, together with the addition of grass, also created suitable conditions for the biodegradation of HCHs and monochlorobenzene/benzene by microbes.

Keep oxygen in check: An improved in-situ zymography approach for mapping anoxic hydrolytic enzyme activities in a paddy soil.

Paddy soils regularly experience redox oscillations during the wetting and draining stages, yet the effects of short-term presence of oxygen (O2) on in-situ microbial hotspots and enzyme activities in anoxic ecosystems remain unclear. To fill this knowledge gap, we applied soil zymography to localize hotspots and activities of phosphomonoesterase (PME), ß-glucosidase (BG), and leucine aminopeptidase (LAP) in three compartments of rice-planted rhizoboxes (top bulk, rooted, and bottom bulk paddy soil) under oxic (+O2) and anoxic (O2) conditions. Short-term (35 min) aeration decreased PME activity by 13-49 %, BG by 4-52 %, and LAP by 12-61 % as compared with O2 in three soil compartments. The percentage of hotspot area was higher by 3-110 % for PME, by 10-60 % for BG, and by 12-158 % for LAP under +O2 vs. O2 conditions depending on a rice growth stage. Irrespective of the aeration conditions, the rhizosphere extent of rice plants for three enzymes was generally greater under higher moisture conditions and at earlier growth stage. Higher O2 sensitivity for the tested enzymes at bottom bulk soil versus other compartments suggested that short-term aeration during conventional zymography may lead to underestimation of nutrient mobilization in subsoil compared to top bulk soil. The intolerance of anaerobic microorganisms against the toxicity of O2 in the cells and the shift of microbial metabolic pathways may explain such a short-term suppression by O2. Our findings, therefore, show that anoxic conditions and soil moisture should be kept during zymography and probably other in-situ soil imaging methods when studying anoxic systems.

In vitro activity of sulbactam-durlobactam against carbapenem-resistant Acinetobacter baumannii and mechanisms of resistance.

OBJECTIVES: Multidrug-resistant Acinetobacter baumannii (MDR-Ab), particularly strains producing oxacillinase (OXA)-type carbapenemases, have rapidly emerged in health care settings as a frequent cause of serious infections with limited treatment options. This study evaluated the in vitro activity of sulbactam (SUL) combined with durlobactam (DUR) against a collection of carbapenemase-producing A. baumannii, and investigated the mechanisms of resistance. METHODS: Susceptibility testing was performed on 100 isolates by either broth microdilution or by the Epsilometer test. Isolates were screened for the insertion sequence ISAba1 upstream of the intrinsic chromosomal blaADC by polymerase chain reaction (PCR). Whole genome sequencing was performed on 25 SUL-DUR resistant isolates, and analyses were performed using the Center for Genomic Epidemiology platform. Target gene sequences were compared to A. baumannii American Type Culture Collection (ATCC) 17978. RESULTS: SUL-DUR exhibited excellent activity against A. baumannii isolates with susceptibility levels as follows: amikacin, 18%; colistin, 91%; cefepime, 5%; imipenem, 0%; minocycline, 46%; SUL, 3%; sulbactam-cefoperazone, 8%; SUL-DUR, 71% (based on a breakpoint at 4 mg/L). Twenty-five non-New Delhi metallo-ß-lactamase (NDM)-producing isolates had SUL-DUR MIC values >4 mg/L, amongst which 14 isolates showed substitutions in penicillin-binding protein (PBP)3, previously shown to be associated with SUL-DUR resistance. Substitutions that have not previously been described were detected in SUL-DUR targets, namely PBP1a, PBP1b, PBP2, and PBP3. By contrast, there was no evidence of the involvement of permeability or efflux. CONCLUSIONS: SUL-DUR exhibited excellent in vitro antibacterial activity against carbapenemase-producing A. baumannii isolates. Amongst the 25 resistant isolates, we identified a number of mechanisms which may be contributing factors, in particular PBP substitutions and the production of specific beta-lactamases.

Pediatric brain abscess - etiology, management challenges and outcome in Lagos Nigeria.

BACKGROUND: Brain abscess in children is a neurosurgical emergency with potentially catastrophic outcome despite the advances made in neuroimaging techniques and antibiotic therapy. Symptoms are nonspecific and may vary with the child's age, location, size, numbers and stage of abscess, and the primary source of infection. Treatment is usually with broad-spectrum antibiotics in combination and surgical evacuation in most cases or antibiotics alone in selected cases with clear-cut indications. This study was to document clinical characteristics, etiological factors, and spectrum of bacteriologic agents responsible for pediatric brain abscess in an African city, the challenges and management outcome over the study period. METHODS: This was a retrospective study over an 11-year period involving 89 children who presented with brain abscess. Information of interest was extracted from the medical records of each participant. The results from data analysis were presented in charts and tables. RESULTS: Eighty-nine children aged 0.85-15.7 years (median age of 6.4 years) met the inclusion criteria. The male-to-female ratio was 1.8:1. Headache (80%), fever (78%), and hemiparesis (78%) were the most common symptoms. Brain imaging deployed was CT scan in 56 (63%), MRI in 9 (10%), and transfontanel ultrasound scan in 24 (27%) children. Seventy-one (80%) children had antibiotics with surgical evacuation while 18 (20%) children received only antibiotics. In 19 (27%) children, the culture of the abscess was negative. In 53 (75%) children, Gram-positive aerobic organisms were isolated. A total of 75 patients (84%) had a favorable outcome. CONCLUSION: Pediatric brain abscess still poses significant public health challenge, especially in resource-limited regions. Successful management of brain abscess requires high index of suspicion for early diagnosis, referral, and intervention.

Metabolic Model of the Nitrogen-Fixing Obligate Aerobe Azotobacter vinelandii Predicts Its Adaptation to Oxygen Concentration and Metal Availability.

There is considerable interest in promoting biological nitrogen fixation (BNF) as a mechanism to reduce the inputs of nitrogenous fertilizers in agriculture, but considerable fundamental knowledge gaps still need to be addressed. BNF is catalyzed by nitrogenase, which requires a large input of energy in the form of ATP and low potential electrons. Diazotrophs that respire aerobically have an advantage in meeting the ATP demands of BNF but face challenges in protecting nitrogenase from inactivation by oxygen. Here, we constructed a genome-scale metabolic model of the nitrogen-fixing bacterium Azotobacter vinelandii, which uses a complex respiratory protection mechanism to consume oxygen at a high rate to keep intracellular conditions microaerobic. Our model accurately predicts growth rate under high oxygen and substrate concentrations, consistent with a large electron flux directed to the respiratory protection mechanism. While a partially decoupled electron transport chain compensates for some of the energy imbalance under high-oxygen conditions, it does not account for all substrate intake, leading to increased maintenance rates. Interestingly, the respiratory protection mechanism is required for accurate predictions even when ammonia is supplemented during growth, suggesting that the respiratory protection mechanism might be a core principle of metabolism and not just used for nitrogenase protection. We have also shown that rearrangement of flux through the electron transport system allows A. vinelandii to adapt to different oxygen concentrations, metal availability, and genetic disruption, which cause an ammonia excretion phenotype. Accurately determining the energy balance in an aerobic nitrogen-fixing metabolic model is required for future engineering approaches. IMPORTANCE The world's dependence on industrially produced nitrogenous fertilizers has created a dichotomy of issues. First, parts of the globe lack access to fertilizers, leading to poor crop yields that significantly limit nutrition while contributing to disease and starvation. In contrast, abundant nitrogenous fertilizers and associated overuse in large agricultural systems result in compromised soil quality and downstream environmental issues. Thus, there is considerable interest in expanding the impacts of BNF to promote improved crop yields in places struggling with access to industrial fertilizers while reducing fertilizer input in areas where overuse results in the degradation of soil health. A more robust and fundamental understanding of BNF biochemistry and microbial physiology will enable strategies to promote new and more robust associations between nitrogen-fixing microorganisms and crop plants.

Bacteriological profile of ocular surface flora in meibomian gland dysfunction.

PURPOSE: To compare the bacteriological profile of meibomian gland secretion and conjunctival cul-de-sac in subjects with and without meibomian gland dysfunction (MGD). METHODS: This hospital-based study enrolled 201 eyes from 201 MGD patients and 84 eyes from 84 age- and gender-matched controls. Samples from the conjunctivae and meibomian gland secretion were obtained. Both aerobic and anaerobic cultures were performed. Differences in the culture-positivity and bacterial strains between two groups were compared. RESULTS: 36.9% and 10.7% of the control meibomian gland secretion recovered aerobes and anaerobes, respectively. A higher rate of aerobic (44.0%) and similar rate of anaerobic (10.7%) bacteria were isolated from the conjunctival cul-de-sac in these controls. Patients with MGD showed significantly higher positive culture rates from both the meibomian gland secretion (75.6% for aerobes and 34.3% for anaerobes) and conjunctival cul-de-sac (64.7% for aerobes and 30.8% for anaerobes). All p values were ≤ 0.001. In both groups and at either location, the predominant species isolated were Staphylococcus epidermidis (aerobes) and Propionibacterium acnes (anaerobes). Of note, the MGD patients harbor a much more complex bacterial profile than the controls. CONCLUSION: Both aerobic and anaerobic bacteria can be isolated from the ocular surface of healthy subjects. Patients with MGD demonstrate significantly higher culture positivity and more complex bacterial profiles than the controls. Bacterial related cytotoxicity and/or inflammation may contribute to the pathological process of MGD.

[Microbial flora and antibiotic susceptibility of purulent tooth diseases in rabbits]. / Keimspektrum und Antibiotikasensitivitäten bei eitrigen Zahnerkrankungen von Kaninchen.

OBJECTIVE: Bacteria involved in purulent tooth disease and the most effective antibiotics were investigated. MATERIAL AND METHODS: Swab samples were taken from 126 rabbits with facial abscesses or purulent periapical inflammation during surgical treatment. Bacteriological examination and susceptibility testing were performed. RESULTS: A wide range of aerobic and anaerobic bacteria were detected. The most commonly isolated anaerobes were gram-negative rods (Prevotella sp., Fusobacterium sp., Bacteroides sp.) and gram-positive non-sporulating cocci (mostly Peptostreptococcus sp.). Of the aerobes, 66.7% were gram-negative (mostly Pasteurella sp., Escherichia coli, Pseudomonas sp.) while 33.3% were gram-positive (mostly Streptococcus sp., Staphylococcus sp.). Depending on the individual patients, fluoroquinolones in combination with amoxicillin-clavulanate, chloramphenicol, amoxicillin-clavulanate, tetracyclines, pradofloxacin, and fluoroquinolone-metronidazole-combinations were most effective. CONCLUSION AND CLINICAL RELEVANCE: Because of the variability of the detected bacteria, considerable differences in antibiotic susceptibility were observed. Therefore, bacterial examination and susceptibility testing are recommended for effective postsurgical treatment of odontogenic abscesses in rabbits.

Identificación de microbiota bucal en caninos en estado de abandono / Identification of Bucal Microbiota in Canines in State of Abandonment

Resumen Objetivo. Describir la microbiota que se encuentra en la cavidad bucal de caninos en condición de abandono de la Fundación Razas Únicas en el municipio de Chía -Cundinamarca. Métodos. Para el estudio se tomaron 29 muestras orales con escobillón a 23 caninos de la Fundación Razas Únicas del municipio de Chía - Cundinamarca. 23 muestras se recolectaron para identificación de bacterias aerobias y anaerobias facultativas, las cuales se transportaron en medio líquido tripticasa soya y 6 muestras para recuperación de bacterias anaerobias estrictas transportadas en medio VMGA-III. El aislamiento de los microorganismos se realizó en medios selectivos y la identificación con el sistema BD BBL™ Crystal™. Resultados. De las 29 muestras analizadas se aislaron 59 bacterias, entre ellas 15 géneros y 15 especies diferentes como; Escherichia coli, Proteus mirabilis, Citrobacter freundii, Enterobacter sakazakii, Enterobacter cloacae, Enterococcus durans, Enterococcus faecalis, Eikenella corrodens, Porphyromonas endodontalis, Fusobacterium spp y Capnocytophaga spp. De acuerdo con la revisión de la literatura, las bacterias anaerobias encontradas están principalmente relacionadas con enfermedad periodontal y las enterobacterias con contaminación oro-fecal.

Abstract Objective. To describe the microbiota found in the oral cavity of canines in condition of abandonment of the Razas Únicas Foundation in the municipality of Chía - Cundinamarca. Methods. For the study, 29 oral samples were taken with a brush from 23 canines from the Razas Únicas Foundation of the municipality of Chía - Cundinamarca. 23 samples were collected for identification of facultative aerobic and anaerobic bacteria, which were transported in soybean tripticase liquid medium and 6 samples for recovery of strict anaerobic bacteria transported in VMGA-III medium. The isolation of the microorganisms was carried out in selective media and identification with the BD BBL™ Crystal™ system. Results. From the 29 samples analyzed, 59 bacteria were isolated, including 15 genera and 15 different species such as Escherichia coli, Proteus mirabilis, Citrobacter freundii, Enterobacter sakazakii, Enterobacter cloacae, Enterococcus durans, Enterococcus faecalis, Eikenella corrodens, Porphyromonas endodontalis, Fusobacterium spp and Capnocytophaga spp. According to the review of the literature, the anaerobic bacteria found are mainly related to periodontal disease and the enterobacteria with oral-fecal contamination.

The investigation of bacteriology of chronic suppurative otitis media in patients attending a tertiary care hospital with special emphasis on seasonal variation.

BACKGROUND: Chronic suppurative otitis media takes a lot of time in the hospital outdoors and a considerable amount of O.T. timings. Chronic suppurative otitis media may be either active chronic otitis media or a sequel of previous otitis media. OBJECTIVE: (a) To understand the bacteriology of Chronic suppurative otitis media (b) Their susceptibility patterns to commonly used antibiotics in this age of emerging resistance (c) the seasonal variation in the bacteriological pattern (d) For better empirical treatment of C.S.O.M where culture facilities are not available so that both intracranial and extra cranial complications can be avoided. MATERIALS AND METHODS: The secretions of 160 samples belonging to various age groups and of both sexes of clinically proven chronic suppurative otitis media with definitive exclusion and inclusion criteria were collected and cultured by aerobic and anaerobic methods. Drug sensitivity was done according to standard laboratory protocols. A month wise visit of the patients has been recorded to note any seasonal variations in the isolates. RESULTS: The most common aerobic organism is Pseudomonas Spp and most common anaerobes isolated being Bacteriodes species. Their susceptibility patterns and seasonal variations have been discussed. CONCLUSIONS: It is observed that chronic suppurative otitis media affects mainly younger group of population, mostly (86.8%) below 40 years of age. Majority of them (31.9%) belonged to, 10-19 years of age. The most common isolate being Pseudomonas Spp. (64.4%) followed by Staphylococcus aureus (33.8%). In the anaerobic group (1.8%) the Bacteriodes species is most prevalent. The most effective antibiotic in the aerobic isolates is Amikacin followed by Gentamicin and Cefotaxime where as for anaerobic isolates Cefoperazone sodium has better sensitivity. The isolation rates of both aerobic and anaerobic groups of organisms are more in the month of July to September, which is the monsoon season in this place. Isolation of Pseudomonas Spp. in Monsoon and post monsoon season may have been due to filling up of water bodies with rain water and infection with an omnipresent saprophytic organism like Pseudomonas Spp.

Incidence of Vibrio cholerae in Fresh Fish and Ceviche in Guadalajara, Mexico.

The incidence of Vibrio cholerae O1 and non-Ol was determined in fresh fish and ceviche, a marinated raw fish dish ready for consumption. Fresh red snapper ( Lutjanus purpureous ) and mackerel ( Scomberomorus sierra ) were obtained from distribution centers, and ceviche from street vendors and small open restaurants in Guadalajara, Mexico. In addition to V. cholerae , the fish samples were tested for aerobic plate count (APC), total volatile nitrogen (TVN), trimethylamine (TMA), and the ceviche for APC, coliforms, and pH. V. cholerae O1 and non-O1 was isolated from 10% and 26% ofthe fish respectively. The mean data for the fish samples were in the region of: APC, 106 CFU/g of fish; more than 25 mg of TVN per 100 g of fish, but less than 5 mg of nitrogen as TMA per 100 g. Eleven percent of the ceviche obtained from street vendors and 6% obtained from restaurants were positive for V. cholerae O1. The mean APC and coliform counts were 6.6 and 4.8 log CFU/g of fish respectively, and the pH of the ceviche ranged from 3.0 to 4.5. All the strains of V. cholerae O1 isolated during this study were identified as biotype El Tor, serotypes Inaba and Ogawa. For both fresh fish and ceviche, the frequency of isolation of V. cholerae was highest during the summer months.

Análise e monitoramento de pontos críticos no abate de frangos utilizando indicadores microbiológicos / Analysis and monitoring of critical points in the poultry slaughter using microbiological indicators

A presença de microrganismos indicadores de contaminação na linha de abate de frangos foi determinada visando identificar os possíveis pontos de controle e oferecer uma opção para o monitoramento ou a verificação pelo sistema "Análise de Perigos e Pontos Críticos de Controle" (APPCC). A contaminação superficial das carcaças foi determinada pela enumeração de microrganismos aeróbios mesófilos, coliformes totais, coliformes termotolerantes e de Escherichia coli nas seguintes fases de abate: A - antes do primeiro chuveiro de higienização, B - após o primeiro chuveiro, C - após a evisceração manual, D - após o chuveiro de lavagem final e E - na saída do pré-resfriamento. Não houve diferença significativa (P<0,05) entre as médias de mesófilos, coliformes totais e termotolerantes, entre as fases A, B, C e D. Entretanto, as médias obtidas para esses microrganismos indicadores na fase E (pré-resfriamento) foram significativamente menores. Não houve diferença significativa entre as médias de Escherichia coli nas cinco fases. As chances de contaminação (Razão de Chances) por mesófilos foram maiores na fase A e por coliformes na fase C. Entre os parâmetros analisados, os níveis de contaminação por mesófilos, coliformes totais e termotolerantes foram os mais indicados para monitoramento e verificação de um plano APPCC no abate de aves. Os resultados obtidos indicaram que a fase de pré-resfriamento pode ser considerada um importante ponto crítico de controle, uma vez que foi capaz de reduzir a contaminação microbiológica de forma significativa.

Hygiene indicator microorganisms in a poultry slaughter was evaluated during the processing in order to identify potential critical control points and allow options for monitoring or verification by Hazard Analysis Critical Control Point (HACCP) system. Microbiological superficial contamination of chicken carcasses was establish by the enumeration of mesophilic aerobes, total coliforms, thermotolerant coliforms and Escherichia coli in the following steps of processing: A - before the first hygienic shower, B - after the first hygienic shower, C - after manual evisceration, D - after final washing shower, and E - after the chiller tank. The mean counts of mesophilic aerobes, total and thermotolerant coliforms was not significantly different (P<0.05) in the steps A, B, C and D. However, the mean values of these microorganisms in step E (after chilling) was significantly lower when compared to the one obtained in the other steps. The mean counts of Escherichia coli were not significantly different, independently of the processing step analyzed. The chances of contamination were estimated by Odds Ration, and it was observed that chances were higher in the step A for mesophilic aerobes, and in the step C for coliforms. Considering the analyzed parameters, the levels of contamination by mesophilic aerobes, total and thermotolerant coliforms were the most suitable for monitoring and verification of a HACCP system in a poultry processing plant. The obtained results indicate that the chilling can be considered as an important critical control point, once this procedure was able to reduce significantly the microbiological contamination.

Pesquisa de Salmonella spp. e microrganismos indicadores em carcaças de frango e água de tanques de pré-resfriamento em abatedouro de aves / Research of Salmonella spp. and indicators microorganisms in poultrycarcasses and chilling tanks water in poultry slaughterhouse

O objetivo desse trabalho foi pesquisar Salmonella spp. e microrganismos indicadores (coliformestotais-CT, coliformes termotolerantes-CTT, aeróbios mesófilos-AM e microrganismos psicrotróficos-MP) em carcaças de frango e água dos tanques de pré-resfriamento em um frigorífico do norte do Paraná.Foram analisadas 120 carcaças de frango (60 antes do pré-chiller e 60 após a saída do chiller) e 120amostras de água (60 pré-chiller e 60 do chiller), totalizando 20 coletas. Para as análises utilizaram-se ametodologia recomendada pela legislação brasileira e sistema PetrfilmTMAC. Salmonella spp. foi isoladaem uma carcaça antes do pré-chiller e outra após a saída do chiller, ambas identificadas como SalmonellaO8, 20: z4, z23. Nas amostras de água foram isolados e identificados seis sorovares no pré-chiller, cincoSalmonella O8,20;z4,z23 e um S. Tennessee. As médias de CT nas carcaças antes do pré-chiller e após asaída do chiller e na água destes tanques foram 3,74 NMP/g, 3,10 NMP/g e 4,00 NMP/100mL / 2,81 NMP/100mL respectivamente; CTT 3,65 NMP/g / 3,00 NMP/g e 3,81 NMP/100mL / 2,73 NMP/100mL; AM 6,40UFC/g / 5,60 UFC/g e 4,40 UFC/mL / 4,13 UFC/mL; MP 4,21 UFC/g e de 3,66 UFC/g. Nas carcaças defrango antes do pré-chiller e após o chiller e na água do pré-chiller e chiller não foi observadadiferença significativa (p>0,05) nos índices de contaminação com relação aos microrganismos indicadoresestudados. Pelos resultados obtidos pode-se concluir que no frigorífico estudado não houve reduçãoda contaminação bacteriana das carcaças durante a passagem pelos tanques.

The purpose of this work was to research the Salmonella spp. and indicators microorganisms (total coliforms-CT, thermotolerant coliforms-CTT, mesophlic aerobes-AM and psychotrophic microorganisms) in poultry carcasses and chilling tanks water in a poultry slaughterhouse in north of Paraná state. Had been analyzed 120 poultry carcasses (60 before the entrance in the chilling tank and 60 after the exit of the chilling tank) and 120 water samples (60 from pre-chiller tank and 60 from chiller tank), totalizing 20 collections. For the analyses was used the brazilian legislation and PetrifilmTMAC. Salmonella spp. was isolated in one poultry carcass before the entrance in the chilling tank and other after the exit of the chilling tank, both identified as Salmonella O8,20;z4,z23. In the water samples was recognized six serovars in pre-chiller tank, five as Salmonella O8,20;z4,z23 and one S. Tennessee. The means of TC on carcasses before the entrance and after the exit of the tanks and in the water samples from pre-chiller tank and in chiller were 3,74 MPN/g / 3,10 MPN/g and 4,00 MPN/100mL / 2,81 MPN/100mL respectively; the mean of TCC was 3,65 MPN/g / 3,00 MPN/g and 3,81 MPN/100mL / 2,73 MPN/100mL; the mean of MA was 6,40 CFU/g / 5,60 CFU/g and 4,40 CFU/mL e 4,13 CFU/mL; the mean of MP was 4,21 CFU/g /3,66 CFU/g and . It was not observed any significant difference (p>0,05) in contamination index neither in poultry carcasses nor in tank water samples. It is possible to conclude that chilling tanks were not able to remove the microorganisms from the carcasses and could contribute to cross-contamination due to elevate water contamination.

Eficácia dos tanques de pré-resfriamento na redução de contaminação bacteriana em carcaças de frango / Chilling tanks effectiveness on the reduction of bacterial contamination of poultry carcasses

O objetivo desta pesquisa foi avaliar a eficácia dos tanques de pré-resfriamento na redução da contaminação microbiana de carcaças de frango. As amostras foram coletadas de um abatedouro no período de março a setembro de 2005, totalizando 20 coletas. Foram coletadas amostras de carcaças em três horários representando o início, meio e final do turno matutino de abate sendo 60 amostras (20 em cada horário) antes da entrada no pré-chiller e 60 amostras (20 em cada horário) após a saída do chiller. As amostras de frango foram submetidas à pesquisa de coliformes totais (CT), coliformes termotolerantes (CTT), aeróbios mesófilos (AM) e psicrotróficos (MP). A enumeração de CT e CCT foi realizada através da técnica dos tubos múltiplos, a de AM através do sistema Petrifilm tmC e a contagem de MP em Agar Padrão para Contagem. As médias mais elevadas do número mais provável de CT e CTT (3,83 log NMP/g e 3,78 log NMP/g, respectivamente) e das contagens de AM e MP (6,61 log UFC/g e 4,58 log UFC/g, respectivamente) nas carcaças ocorreram no primeiro horário de coleta, antes da entrada no pré-chiller. Observou-se uma diminuição significativa (p<0,05) do NMP de CT e CTT e contagem de AM nas carcaças, após a saída dos tanques de resfriamento, no primeiro horário de coleta, indicando que os tanques de pré-resfriamento, no frigorífico estudado, foram eficazes na remoção de microrganismos das carcaças apenas no início dos trabalhos de abate. Não foi detectada a presença de CT e CTT nas amostras de águas de abastecimento.