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Effect of Different Doses of Mixed Fertilizer on Some Biogeochemical Cycling Bacterial Population in Carp Culture Pond

Effect of Different Doses of Mixed Fertilizer on Some Biogeochemical Cycling Bacterial Population in Carp Culture Pond

Balanced bacterial growth requires substrates with carbon, nitrogen and phosphorus in an atomic ratio of 106 : 12 : 1 (Goldman et al., 1987), although bacteria have some capacity to tolerate these requirements (Tezuka, 1990). According to Ghosh and Chattopadhyay (2005), the optimum C : N and N : P ratio were 28-29 : 1 and 3-7 : 1 for maximum abundance of mineralizing bacterial population, respectively. The role of C : N : P ratio as well as N/P ratio of ambient water in regulating the food chain through selective pressure on the certain organisms has been emphasized (Jana et al., 2001). Direct dose dependent gradual rise N/P ratio of ambient waters of all the treatments despite application of different doses of input fertilizer with constant N/P ratio implied that nitrogen tended to rise gradually with increase in absolute phosphate fertilizer dose indicates that phosphorus is more favourable over nitrogen and can be used at a much faster rate compared to nitrogen (Jana et al., 2001). While examining the Abstract

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Identification and potential application of bacterial population in biogranule for the treatment of textile wastewater

Identification and potential application of bacterial population in biogranule for the treatment of textile wastewater

Identification of bacterial population in a wastewater treatment system is an important task as this enable determination of the treatment performance. A microbial interaction with pollutants in the wastewater varies according to the types of bacteria in the consortium population that determine how they interact with each other and with their environment. Due to this fact, identification of bacteria population would be useful. However, conventional method for bacterial identification using culture method would be highly time consuming, costly and laborious. In addition, it contributes to high error and bias (Abdullah et al., 2011; Muda et al., 2010).

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Lethal Consequences of Overcoming Metabolic Restrictions Imposed on a Cooperative Bacterial Population

Lethal Consequences of Overcoming Metabolic Restrictions Imposed on a Cooperative Bacterial Population

We first showed that QsmR rewires metabolic networks at the branch point of the glyoxylate cycle and TCA cycle in B. glumae. This indicated that QsmR functions as a transcriptional activator and a repressor, which is not unusual because transcriptional regulators belonging to the IclR type are often bifunctional (21). Such metabolic rewiring by bifunctional QsmR raised questions as to what the underlying reasons are and whether it is related to bacterial cooperativity. We chose B. thailandensis E264 as a system comparable to B. glumae, because it also exhibited QmsR-dependent oxalate biosynthesis (11) as well as an 80.53% identity with B. glumae BGR1 at the genome level, as calculated by average nucleotide identity (ANI) based on BLAST ⫹ (ANIb) parameters (22). Concerns about the possibility that QsmR-mediated metabolic rewir- ing is a peculiar phenomenon in B. glumae were dismissed since expression of aceA, glcB, and icd genes in B. thailandensis exhibited the same gene regulation patterns as those observed in B. glumae. This phenomenon appears to be widely distributed among the members of the Burkholderia genus. Recent QS-dependent transcriptome analysis in B. thailandensis showed that expression of both the aceA and glcB genes is not controlled by QS (12). However, this may be due to different culture conditions. For QS-dependent transcriptome analysis, the strains of B. thailandensis were grown in LB supplemented with 50 mM MOPS (morpholinepropanesulfonic acid) (12) whereas expression of both the aceA and glcB gene was estimated in B. thailandensis cells grown in LB broth without any buffer in this study.

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RAPD Analysis of Leaf Litter Associated Bacterial Population From Canal, Kollemcode

RAPD Analysis of Leaf Litter Associated Bacterial Population From Canal, Kollemcode

The bacterial isolates were isolated from leaf litter by serial dilution agar plating method. After the incubation, serially diluted agar plated samples showed seven different types of bacterial isolates and indicated as B1, B2, B3, B4, B5, B6, B7. RAPD Analyses

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Isolation and identification of bacterial population from various  soil samples

Isolation and identification of bacterial population from various soil samples

Biochemical Identification of the bacterial isolates: This was done with VITEK 2 compact technology. The VITEK 2 is an automated microbial identification system that provides highly accurate and reproducible results as shown in multiple independent studies. With its colorimetric reagent cards, and associated hardware and software advances, the VITEK 2 offers a stateoftheart technology platform for phenotypic identification methods.

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Effect of Nickel on Bacterial Population in Soil

Effect of Nickel on Bacterial Population in Soil

Abstract: Soil is considered as the naturally existing physical covering of the earth’s surface and are home for innumerable microbes. These microbes help in keeping soil health in its proper manner. Any small variation in natural constituent of soil will alter these microbes, which affects the soils. Anthropogenic activities increased the accumulation of heavy metals in the soil. Nickel is one of the metal which present naturally in the serpentine soils. Micro flora and fauna of serpentine soils are tolerant to the presence of nickel. Nickel is a micronutrient for microbes and plant. High nickel concentration reduces the pH and decreases the bacterial count. Present study reveals that presence of both gram positive and gram negative bacteria in soils and at higher concentrations the number of both gram negative and positive cocci is reduced. Hence data demonstrate the relationship between Nickel and soil bacteria at various concentrations. Keywords: Heavy metal, Nickel, Serpentine soils, pH, Soil microbes

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Stochastic Gene Expression in Fluctuating Environments

Stochastic Gene Expression in Fluctuating Environments

Stochastic mechanisms can cause a group of isogenic bacteria, each subject to identical environmental conditions, to nevertheless exhibit diverse patterns of gene expression. The resulting phenotypic subpopula- tions will typically have distinct growth rates. This behavior has been observed in several contexts, including sugar metabolism and pili phase variation. Under fixed environmental conditions, the net growth rate of the population is maximized when all cells are of the fastest growing phenotype, so it is unclear what fitness advantage is conferred by population heterogeneity. However, unlike ideal laboratory conditions, natural environments tend to fluctuate, either periodically or randomly. Here we use a stochastic population model to show that, during growth in such fluctuating environments, a dynamically heterogenous bacterial population can sometimes achieve a higher net growth rate than a homogenous one. By using stochastic mechanisms to sample several distinct phenotypes, the bacteria are able to anticipate and take advantage of sudden changes in their environment. However, this heterogeneity is beneficial only if the bacterial response rate is sufficiently low. Our results could be useful in the design of artificial evolution experiments and in the optimization of fermentation processes.

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Bacteriophages Limit the Existence Conditions for Conjugative Plasmids

Bacteriophages Limit the Existence Conditions for Conjugative Plasmids

We investigated how the ecological and population genetic ef- fects of lytic bacteriophages on bacteria affect the persistence of conjugative plasmids by studying experimental evolution of the plant-associated soil bacterium Pseudomonas fluorescens SBW25 (20) and its naturally associated megaplasmid, pQBR103 (21), along with the lytic phage SBW25␸2 (18). pQBR103 carries a mercury resistance operon that allows the host bacterium to reduce mercuric ions to elemental mercury and thereby detoxify mercury-contaminated en- vironments (22). We then used a combination of simple analytical mathematical models and individual-based evolutionary simula- tions to explain the observed dynamics. Mathematical models have been previously used to predict the basic behavior of plasmid population biology via conjugation and loss through segregation (2, 3). Individual-based modeling of bacterial population biology has been well explored (23, 24), but there are relatively few com- putationally explicit models of plasmid dynamics (6). Use of a tandem modeling approach allowed the more complex individual-based simulations to be benchmarked against simpler, general mathematical models that can be solved exactly, which is rarely attempted in interdisciplinary modeling (25).

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Colonisation resistance in the sand fly gut: Leishmania protects Lutzomyia longipalpis from bacterial infection

Colonisation resistance in the sand fly gut: Leishmania protects Lutzomyia longipalpis from bacterial infection

Female sand flies were infected with L. mexicana 3 days after emergence as described above. Infected sand flies were transferred to a new cage and maintained with autoclaved 70% w/v sucrose solution on cotton wool for 4 days. Leishmania-infected sand flies were then orally challenged with Serratia, re-suspended to give a concen- tration of 5.7 × 10 7 cfu mL -1 in autoclaved 20% w/v su- crose solution and fed to Leishmania-infected sand flies daily via cotton wool. Cotton wool moistened with Ser- ratia solution was changed daily and sand fly survival was monitored for 6 days after bacterial challenge and compared with uninfected bloodfed sand flies that were also challenged with Serratia. Additional control groups consisted of Leishmania-infected and bloodfed sand flies fed with sterile 20% w/v sucrose solution via cotton wool. Sand fly Leishmania infections were estimated by dissecting infected sand fly guts at 72 h after starting Serratia feeding. Bacterial population size was also esti- mated in the gut by dissecting insects 72 h post-infection, four pools of 3 midguts were homogenised in 50 μl of PBS per pool and serial dilutions were inoculated onto LB agar plates and incubated at 26°C for 24 h.

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Article:  Effects of feeding Bacillus subtilis to heat stressed broiler chickens with or without an antibiotic growth promoter

Article: Effects of feeding Bacillus subtilis to heat stressed broiler chickens with or without an antibiotic growth promoter

In mid 1940s, the use of antibiotics became a common practice in broiler production. There is increasing public health concern, over the use of antibiotic for growth promotion in food animal production that relates to the contribution of this use to increasing rates of antibiotic resistance. The European Union, in 1999, banned the use of most antibiotics for growth promotion to preserve the effectiveness of important human drugs (Casewell et al., 2003).In Bangladesh, there is a growing concern not to use antibiotic growth promoter in poultry diets unnecessarily, rather to find out alternatives to commonly used antibiotic to act as performance enhancer as well as for the improvement of gut health. Currently, probiotics have been used as a feed supplement in diets of different classes of poultry to enhance productive performance and immune responses. Probiotics supplementation to broiler diets had positive effects on body weight gain, feed conversion ratio, and mortality rate in broiler chickens (Anjum et al., 2005). Probiotics can also benefit the host animal by enhancing the synthesis of certain vitamins, providing digestive enzymes and increasing the production of volatile fatty acids that are finally metabolized in favour of the host (Fritts et al., 2000). Since, stress mitigating products are always costly, so any additional usages to minimize heat stress must be justified over the cost of production. In this study, an attempt has been made to explore the beneficial effects of Bacillus subtilies strain containing probiotic on heat stressed commercial broiler chickens given diets with or without an antibiotic growth promoter. Bacillus subtilis is a number of the mucosa associated bacterial population in the caeca of the chicken (Gong et al., 2002). The specific objectives of this experiment were: 1) to investigate the effects of Bacillus subtilis containing PB on heat stressed commercial broilers when supplemented alone or in combination with AGP; 2) to determine the carcass characteristics of finished broilers receiving different treatments and 3) to determine the cost-effectiveness of the application of PB and AGP in broiler production.

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Polymerase Chain Reaction molecular diagnostic technology for monitoring chronic osteomyelitis

Polymerase Chain Reaction molecular diagnostic technology for monitoring chronic osteomyelitis

that these animals might not have had, or were not going to progress to, established chronic osteomyelitis, and potentially would have cleared the microorganisms immunologically, and that the PCR test was detecting nucleic acid from the original bacterial population in the inoculum, and not focal disease resulting from pathogenic proliferation in vivo. However, it is highly unlikely that any organisms from the inoculum would have remained intact in a healthy, immunoreactive animal for 4 weeks, without clearance by the immune system, to result in false positive PCR results. More plausible is that growth and expansion of the inoculum bacterial population did occur in these animals, and that even though classic osteomyelitis was not fully established based on standard radiographic evidence (Figure 1), underlying bacterial proliferation and colonization that would eventually manifest as chronic disease was indeed taking place, and was in fact detectable by the more sensitive molecular assay, but not by micro- biological or radiographic analysis. These findings demon- strate that the molecular test, if used appropriately in clinical situations where osteomyelitis is suspected, or where a definite probability of its development exists be- cause of the clinical history of the patient, could be a valu- able diagnostic assay for detecting low bacterial loads in the early stages of infection, prior to fully developed dis- ease, at a time when antimicrobial therapy would be the most effective.

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Horizontally transferred genes cluster spatially and metabolically

Horizontally transferred genes cluster spatially and metabolically

A) A larger bacterial population will likely experience more neutral and nearly neutral transfers into members of the population. If the number of genes acquired by mem- bers of the population is proportional to population size, then similar to the rate for neutral substitutions being in- dependent of population size, one should expect that the fixation of neutral acquired genes due to drift is independ- ent of populations size. The impact of population size is on what is seen by selection as advantageous or detrimen- tal, i.e. a large population will have fewer nearly neutral ac- quired genes. Many recently acquired genes in individual bacterial genomes appear to not increase the fitness of the recipient, and many of these genes are likely to be lost from the population on the long run [4, 7].

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Bacteriophages limit the existence conditions for conjugative plasmids

Bacteriophages limit the existence conditions for conjugative plasmids

We investigated how the ecological and population genetic ef- fects of lytic bacteriophages on bacteria affect the persistence of conjugative plasmids by studying experimental evolution of the plant-associated soil bacterium Pseudomonas fluorescens SBW25 (20) and its naturally associated megaplasmid, pQBR103 (21), along with the lytic phage SBW25 ␸ 2 (18). pQBR103 carries a mercury resistance operon that allows the host bacterium to reduce mercuric ions to elemental mercury and thereby detoxify mercury-contaminated en- vironments (22). We then used a combination of simple analytical mathematical models and individual-based evolutionary simula- tions to explain the observed dynamics. Mathematical models have been previously used to predict the basic behavior of plasmid population biology via conjugation and loss through segregation (2, 3). Individual-based modeling of bacterial population biology has been well explored (23, 24), but there are relatively few com- putationally explicit models of plasmid dynamics (6). Use of a tandem modeling approach allowed the more complex individual-based simulations to be benchmarked against simpler, general mathematical models that can be solved exactly, which is rarely attempted in interdisciplinary modeling (25).

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“Sensibility of Methicillin Resistant Staphylococcus aureus to Essential oil of Thymus ciliatus” by Heni Sonia, Abdesselam Amira, Kermiche Fella, Bennadja Salima, Djahoudi Abdelghani, Algeria.

“Sensibility of Methicillin Resistant Staphylococcus aureus to Essential oil of Thymus ciliatus” by Heni Sonia, Abdesselam Amira, Kermiche Fella, Bennadja Salima, Djahoudi Abdelghani, Algeria.

The essential oil extracted from the aerial parts of Thymus ciliatus, harvested in the region of Tawra (North-East Algeria), gave an excellent yield of 2.5%. Its analysis by GC/MS allowed identification of twenty-four elements, mainly phenols and terpens. The main components are: thymol (67.78%), p-cymen (12.25%), pseudo-limonen (5.10%), and γ -terpinen (4.42%). The main aim of this study is to evaluate the antibacterial activity of this essential oil on a bacterial population consisted of forty-four strains of Staphylococcus aureus resistant to methicillin (MRSA), isolated from different food products. For that, we used the agar diffusion method as recommended by the European Committee on Antimicrobial Susceptibility Testing [CASFM- EUCAST; 2014- V2]. The calculation of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined by the medium agar incorporation method as recommended by [CASFM- EUCAST; 2014- V2]. MRSA strains tested, showed a high sensitivity in respect of the essential oil with inhibition diameters ranging from 20mm to 50mm and relatively low MICs values ranging from 180µg/ml and 720µg/ml, and CMBs values ranging from 180µg/ml and 2160µg /ml. The essential oil of T. ciliatus showed a bactericidal effect on all isolated MRSA with a very important report CMB / CMI = 1. The bactericidal power of this oil suggests its use in foods as a substitute for conventional chemical preservatives.

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Studying the Symbiotic Bacterium Xenorhabdus nematophila in Individual, Living Steinernema carpocapsae Nematodes Using Microfluidic Systems

Studying the Symbiotic Bacterium Xenorhabdus nematophila in Individual, Living Steinernema carpocapsae Nematodes Using Microfluidic Systems

Error contributes to our measurements of bacterial population size. For instance, while imaging, some nematodes move in response to light, which can interfere with fluorescence measurements. Traps with smaller dimensions than those used here can constrain nematode movement and reduce this source of error. Epifluorescence mi- croscopy collects light from focal planes above and below the sample that can introduce uncertainty into fluorescence quantification. This effect can be transcended by confocal microscopy; however, analyzing confocal data is often nontrivial, as bac- terial cells are aligned in all directions and cell outlines are not always easily distin- guishable, which can introduce bias and uncertainty when counting cells, in addition to the analysis being less easily automated. The wide availability of epifluorescence microscopy in part led us to select this method for this first study. Another potential source of error may arise from normalizing integrated intensity to single-cell intensity, as fluorescence will vary from cell to cell (45). Nematode-to-nematode differences in initial bacterial load coupled with the current inability to synchronize the nematodes through the reproductive cycle will also increase the heterogeneity in measurements. Several microfluidic devices that isolate individual nematodes have been published; however, the majority of these systems require microfluidics expertise for their oper- ation (29, 30). Our goal was to provide the field with a tool to enable microbiology and nematology laboratories to perform long-timescale, single-nematode studies. Conse- quently, the design minimized the number of accouterments required to operate the systems: disposable syringes, needles, and tubing. We provide a link to download a vector graphics file of the device blueprint in the supplemental material; using this file, laboratories can purchase a device “master” and fabricate their own microfluidic devices (see the supplemental material for device design downloads). The device is easy to operate, and we anticipate that experts in biology areas outside engineering will find the devices valuable in their studies of single organisms interacting with symbionts.

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Bacteriophages limit the existence conditions for conjugative plasmids

Bacteriophages limit the existence conditions for conjugative plasmids

We investigated how the ecological and population genetic ef- fects of lytic bacteriophages on bacteria affect the persistence of conjugative plasmids by studying experimental evolution of the plant-associated soil bacterium Pseudomonas fluorescens SBW25 (20) and its naturally associated megaplasmid, pQBR103 (21), along with the lytic phage SBW25␸2 (18). pQBR103 carries a mercury resistance operon that allows the host bacterium to reduce mercuric ions to elemental mercury and thereby detoxify mercury-contaminated en- vironments (22). We then used a combination of simple analytical mathematical models and individual-based evolutionary simula- tions to explain the observed dynamics. Mathematical models have been previously used to predict the basic behavior of plasmid population biology via conjugation and loss through segregation (2, 3). Individual-based modeling of bacterial population biology has been well explored (23, 24), but there are relatively few com- putationally explicit models of plasmid dynamics (6). Use of a tandem modeling approach allowed the more complex individual-based simulations to be benchmarked against simpler, general mathematical models that can be solved exactly, which is rarely attempted in interdisciplinary modeling (25).

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Short Term International Study For Teachers As A Form of Experiential Learning: A Case Study of American Educators in Turkey

Short Term International Study For Teachers As A Form of Experiential Learning: A Case Study of American Educators in Turkey

(OsteoPerio Study), an ancillary study of the Women’s Health Initiative (WHI) Observational Study (OS) seeking to “examine the association between osteoporosis, oral bone loss, and periodontal disease in a well-characterized cohort of postmenopausal women” (Sahli et al., 2015). The OsteoPerio study has previously been reviewed and approved by the Health Sciences Institutional Review Board at the University at Buffalo, and all participants provided signed informed consent. Participants were offered an incentive of a free bone density scan and an oral examination (Brennan et al., 2007). Procedures for study recruitment, retention, and data collection have been previously described (Wactawski-Wende et al., 2005; Brennan et al., 2007; Sahli et al., 2015). My study population is comprised of 1,206 female participants; the population was reduced from 1,256, as participants with missing values for all exposures and outcomes of interest were excluded.

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Atypical bacterial pneumonia in the HIV-infected population

Atypical bacterial pneumonia in the HIV-infected population

Currently, the diagnosis of pneumonia is based on clinical features and X-ray. The etiological diagnosis, however, is based on empirical data, culture, serology, nucleic acid amplification techniques (NAAT), and bronchoscopy [5, 14]. When choosing any of these diagnostics, a number of points must be considered. Although very informative, empirical data (i.e. patient history, recent travel, intravenous [IV] drug exposure, prior infections, or antibiotic exposure) can only aid in narrowing the scope of infection and is not definitive [5]. In contrast, culture allows bacterial identification and is considered the preferred method in diagnostics. However, incubation periods can be lengthy (depending on the growth rate of the microorganism), not all microbes are cultivable, and the sensitivity of the assay decreases if the patient has had any pre-treatment with antibiotics [15]. Serological tests rely on the patient’s ability to mount an effective antibody response; however, in the case of HIV, this response is greatly reduced.

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Microbial Analysis and Proximate Composition of Boiled and Fried Local Cheese (WARA)

Microbial Analysis and Proximate Composition of Boiled and Fried Local Cheese (WARA)

Abstract- Fried cheese locally called Wara gets spoiled when attacked by pathogenic bacteria, as a result of poor hygiene practice by the producer and handlers. Wara samples were bought in Ilesha at Atakumosa market square Osun-state. This research was designed to isolate and enumerate microorganisms using standard microbial methods, proximate composition and the nutritional composition of boiled local and fried cheese (wara). Proximate analysis was carried out to determine nutritional composition. Klebsiella species and Esherichia coli Staphylococcus epidermidis, Bacillus species, Escherichia coli, Salmonella species, Streptococcus species, Clostridium species and Lactobacillus species were isolated using standard technique. The highest bacteria count for the fried cheese was 2.1×10 5 cfu/ml the lowest bacterial count was 1.5×10 5 cfu/ml unit highest bacterial count of the boiled local cheese was 4.4×10 5 (cfu/ml), lowest bacterial count was 1.8×10 5 (cfu/ml) while the range of the values was 2.6×10 5 . Fungi isolated were Penicillium and Gymnoase. Fat content for the boiled cheese has the highest mean value of 44.78 ±0.028cfu/ml and Ash had lowest mean value of 2.46±0.014cfu/ml. The moisture content of fried cheese had the highest mean value 55.32±0.014 while the carbohydrate had the lowest mean value 0.63±0.02 for fried chesse. Fibre content was not detected in both samples. The microbial contamination might generally occur based on lack of standardization, fecal contamination and poor personal hygiene in the production, handling and storage. Therefore, all cheese producers and consumers should take care during processing and storage of the cheese to prevent contamination.

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Identification of Population Bottlenecks and Colonization Factors during Assembly of Bacterial Communities within the Zebrafish Intestine

Identification of Population Bottlenecks and Colonization Factors during Assembly of Bacterial Communities within the Zebrafish Intestine

The identification of genes that were important for coloniza- tion by both species in both monoassociation and concurrent di- association situations, such as those involved in GlcNAc metabo- lism and resistance to antimicrobial peptides, suggests that these genes are likely to encode components of mechanisms of general, rather than species-specific, importance during initial coloniza- tion of the zebrafish intestine. Further studies of multiple genes involved in these processes involving clean deletions followed by complementation are needed to verify the importance of these pathways during colonization of the zebrafish intestines. For ex- ample, multiple GlcNAc metabolism-related genes were identified in both species as being important for colonization, and GlcNAc derived from fish intestinal mucus might potentially be an impor- tant nutrient source for colonizing bacteria. However, as GlcNAc metabolism and modifications are important for many physiolog- ical processes in bacteria, it remains to be directly shown whether this specific sugar’s catabolism from host-derived sources is im- portant for colonization or whether dysregulation of other bacte- rial pathways is the cause of the colonization defects. Notably, we also identified many hypothetical proteins and genes of general functional prediction only, showing that even in these relatively well-characterized gammaproteobacteria, a significant portion of the genome is yet to be functionally characterized with regard to colonization. The process of colonization of the fish intestine by bacteria is itself a multifaceted process involving processes exter- nal to the animal as well, such as bacterial competition and pro- liferation within the water, positioning within the water column, and potentially, movement toward the fish. Similarly, some mam- malian intestinal pathogens must survive in an aqueous environ- ment to be effectively transmitted and colonize a new host. A recent transposon insertional mutagenesis

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