Significance and Roles of Proteus spp. Bacteria in Natural Environments

Evaluation of the Resistance Profile of Bacteria Obtained From Infected Sites of Dogs in a Veterinary Teaching Hospital in Brazil: A Retrospective Study

The aim of this study was to evaluate the prevalence and antimicrobial resistance profile of bacterial species isolated from infected sites of canines. All samples were collected from canine patients who received clinical or surgical care at the veterinary teaching hospital between March 2016 and November 2017. The samples were analyzed in a private pathology laboratory. A descriptive analysis of 295 antimicrobial susceptibility test reports was performed. Staphylococcus spp. (104/295 [35.25%]), Escherichia coli (100/295 [33.90%]), Proteus spp. (44/295 [14.92%]), Pseudomonas spp. (25/295 [8.47%]), and Klebsiella spp. (20/295 [6.78%]) were more frequently isolated, and a high incidence of multidrug resistance was observed (69,83% [206/295]). Methicillin-resistant Staphylococcus spp. accounted for 33% (33/100) of the Staphylococcus strains. Enterobacteriaceae cefotaxime resistance constituted 22.82 ± 4.49% and Enterobacteriaceae imipenem resistance constituted 5% (1/20) for Klebsiella spp., 5% (5/100) for E coli, and 6.82% (3/44) for Proteus spp. Pseudomonas spp. strains accounted for 8% (2/25) of imipenem resistance and 45.45% (10/22) of polymyxin B resistance. Our findings revealed a high rate of multidrug-resistant bacteria involvement in the infectious process of dogs. From the perspective of the One Health scenario, our results showed alarming data, given the high risk of resistant-strain dissemination between animals, owners, and healthcare professionals. There is an urgent need for strategies to control and prevent the evolution of new multidrug-resistant bacteria in veterinary hospitals. It is also crucial to understand and emphasize the role of veterinary professionals in this public health battle.

Antibacterial Use of Macroalgae Compounds against Foodborne Pathogens

The search for food resources is a constant in human history. Nowadays, the search for natural and safe food supplies is of foremost importance. Accordingly, there is a renewed interest in eco-friendly and natural products for substitution of synthetic additives. In addition, microbial contamination of food products during their obtaining and distribution processes is still a sanitary issue, and an important target for the food industry is to avoid food contamination and its related foodborne illnesses. These diseases are fundamentally caused by certain microorganisms listed in this review and classified according to their Gram negative or positive character. Algae have proven to possess high nutritional value and a wide variety of biological properties due to their content in active compounds. Among these capabilities, macroalgae are recognized for having antimicrobial properties. Thus, the present paper revises the actual knowledge of microbial contaminants in the food industry and proposes antimicrobial algal compounds against those pathogenic bacteria responsible for food contamination as valuable molecules for its growth inhibition. The capacity of algae extracts to inhibit some major food pathogen growth was assessed. Moreover, the main applications of these compounds in the food industry were discussed while considering their favorable effects in terms of food safety and quality control.

Clinical significance of Proteus mirabilis bacteriuria in dogs, risk factors and antimicrobial susceptibility

The objectives of this study were to describe the in vitro antimicrobial susceptibility and clinical significance of Proteus mirabilis in canine bacteriuria and to identify the risk factors associated with P. mirabilis urinary tract infections. This is a retrospective observational study of 48 P. mirabilis-positive canine urinary cultures. Only 22 of the 48 P. mirabilis isolates (45.8%) were non-susceptible to at least one tested antimicrobial. Most P. mirabilis isolates (98%) were susceptible to enrofloxacin, 93.7% to amoxicillin/clavulanic acid, and 85.4% to ampicillin, cephalothin, and trimethoprim-sulfamethoxazole. Five multidrug-resistant isolates were detected (10.4%). A significant increase in antimicrobial resistance was observed over the study period. Positive P. mirabilis cultures were associated with bacterial cystitis in 36 of 39 dogs (92.3%), pyelonephritis in 2 of 39 dogs (5.1%), and one dog had both bacterial cystitis and pyelonephritis (2.5%). There was no subclinical bacteriuria. Most urinary tract infections were complicated as risk factors were identified in 37 of 39 dogs (94.8%). The most commonly identified risk factors were the presence of a contaminated peri-vulvar area with urine/feces or a hypoplastic vulva. To conclude, P. mirabilis bacteriuria was associated with upper and lower urinary tract infections in this study and was found more frequently in complicated bacterial cystitis. Multidrug-resistant isolates and increased P. mirabilis antimicrobial resistance have been identified over the last 10 years, but most isolates remain susceptible to first-line antimicrobials such as amoxicillin and trimethoprim-sulfamethoxazole.

Extended spectrum beta lactamase producing bacteria among outpatients with ear infection at FelegeHiwot Referral Hospital, North West Ethiopia

BACKGROUND

Antibiotic resistant bacteria particularly extended-spectrum beta lactamase (ESBL) producing are of major concern for management of outpatients. They can spread rapidly and are associated with poor patient outcome. However, there is scarcity of information on ear infection with ESBL producing bacteria in Ethiopia. Therefore, this study investigates the prevalence of ear infection with ESBL producing bacteria among outpatients attending Felegehiwot Referral Hospital, Northwest Ethiopia.

METHODS

A hospital based cross-sectional study was conducted from May, 2018 to January, 2019. Demographic and clinical data were collected with face to face interview and were complemented with patient card review. Ear discharge specimens were collected from study participants using swab technique. All ear swab specimens were cultured using standard microbiological techniques. The ESBL producing bacteria were detected by double disc synergy test and interpreted based on Clinical and laboratory Standards Institute Guidelines. Chi-square and fisher's exact tests were calculated to check association between variables.

RESULTS

A total of 236 patients (male = 138 and female = 98) with ear infection took part in the study. The median age of the participants was 20years. Overall, 10 (4.23%, 95%CI; 2.3-7.6%) of patients had ear infection with ESBL producing bacteria. Other chronic illnesses (p = 0.003), history of hospital visit and treatment (p = 0.006) and history of antibiotic use without physician's prescription (p<0.001) had significant association with prevalence of ESBL producing bacteria in ear infection. The proportion of ear infection with ESBL producing P.mirabilis, P.aeruginosa and K.pneumoniae were 4 (1.7%), 3 (1.3%) and 2 (0.8%), respectively. All ESBL producing isolates were MDR (100%). Overall, 58 (43%) species were MDR. P.aeruginosa was the leading MDR isolate 29 (53.7%).For all bacterial isolates of ear infection, ampicillin(93.3%) and amoxicillin-clavulanic acid (58.5%) revealed high level of resistance whereas low resistance rates were observed for ciprofloxacin (5.2%), third generation cephalosporin (11.9-20%) and aztreonam (16.3%).

CONCLUSIONS

Ear infection due to ESBL producing bacteria coupled with high levels of MDR is becoming a growing concern for outpatients in the study area. Regular detection of these bacteria and wise use of antibiotics are needed to stop the spread of this form of resistance.

Combination of urease inhibitor and antiseptic inhibits urea decomposition-induced ammonia production by Proteus mirabilis

The decomposition of urea into ammonia by urease-producing bacterium shows an elevation in the pH level, which can lead to incontinence-associated dermatitis (IAD). This study aimed to examine the efficacy of a combination of antiseptic and urease inhibitor in inhibiting the decomposition of urea by the urease-producing bacterium Proteus mirabilis. We performed in vitro assays to compare the effects of a combination of antiseptic and urease inhibitor, antiseptic only, urease inhibitor only, and an untreated control with the effects of a urea-containing solution. Cultured P. mirabilis was mixed with urea-containing solution, followed by the addition of antiseptic and/or urease inhibitor. The main outcome used to assess the efficacy of the different treatments was ammonia concentration at 4-hours post-treatment initiation, and multiple comparison analysis was performed using Dunnett's test to compare the results between groups. Ammonia concentrations in samples treated with either antiseptic or urease inhibitor were lower than those in the untreated control, while the combination of antiseptic and urease inhibitor resulted in decreased ammonia concentrations compared with either treatment alone. Therefore, the application of both urease inhibitor and antiseptic is more effective for the inhibition of urea decomposition by urease-producing bacteria. Novel preventive strategies using these reagents may be effective for preventing IAD.

Establishment and Application of a Dual TaqMan Real-Time PCR Method for Proteus Mirabilis and Proteus Vulgaris

Proteus species are common opportunistic bacteria and foodborne pathogens. The proper detection of Proteus can effectively reduce the occurrence of food-borne public health events. Proteus mirabilis and Proteus vulgaris are the two most important pathogens in the Proteus genus. In this study, a dual TaqMan Real-Time PCR method was established to simultaneously detect and distinguish P. mirabilis and P. vulgaris in samples. The method exhibited good specificity, stability, and sensitivity. Specifically, the minimum detection concentrations of P. mirabilis and P. vulgaris in pure bacterial cultures were 6.08 × 10² colony forming units (CFU)/ml and 4.46 × 10² CFU/ml, respectively. Additionally, the minimum detectable number of P. mirabilis and P. vulgaris in meat and milk was 10³ CFU/g. In addition, the method can be used to distinguish between strains of P. mirabilis and P. vulgaris within two hours. Overall, it is a sensitive, easy-to-use, and practical test for the identification and classification of Proteus in food.

Proteus mirabilis Biofilm: Development and Therapeutic Strategies

Proteus mirabilis is a Gram negative bacterium that is a frequent cause of catheter-associated urinary tract infections (CAUTIs). Its ability to cause such infections is mostly related to the formation of biofilms on catheter surfaces. In order to form biofilms, P. mirabilis expresses a number of virulence factors. Such factors may include adhesion proteins, quorum sensing molecules, lipopolysaccharides, efflux pumps, and urease enzyme. A unique feature of P. mirabilis biofilms that build up on catheter surfaces is their crystalline nature owing to their ureolytic biomineralization. This leads to catheter encrustation and blockage and, in most cases, is accompanied by urine retention and ascending UTIs. Bacteria embedded in crystalline biofilms become highly resistant to conventional antimicrobials as well as the immune system. Being refractory to antimicrobial treatment, alternative approaches for eradicating P. mirabilis biofilms have been sought by many studies. The current review focuses on the mechanism by which P. mirabilis biofilms are formed, and a state of the art update on preventing biofilm formation and reduction of mature biofilms. These treatment approaches include natural, and synthetic compounds targeting virulence factors and quorum sensing, beside other strategies that include carrier-mediated diffusion of antimicrobials into biofilm matrix. Bacteriophage therapy has also shown successful results in vitro for combating P. mirabilis biofilms either merely through their lytic effect or by acting as facilitators for antimicrobials diffusion.

Unveiling the Multipath Biosynthesis Mechanism of 2-Phenylethanol in Proteus mirabilis

Proteus mirabilis could convert l-phenylalanine into 2-phenylethanol (2-PE) via the Ehrlich pathway, the amino acid deaminase pathway, and the aromatic amino acid decarboxylase pathway. The aromatic amino acid decarboxylase pathway was proved for the first time in P. mirabilis. In this pathway, l-aromatic amino acid transferase demonstrated a unique catalytic property, transforming 2-penylethylamine into phenylacetaldehyde. Eleven enzymes were supposed to involve in 2-phenylethanol synthesis. The mRNA expression levels of 11 genes were assessed over time by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in vivo. As a result, the expression of 11 genes was significantly increased, suggesting that P. mirabilis could transform l-phenylalanine into 2-phenylethanol via three pathways under aerobic conditions; nine genes were significantly overexpressed, suggesting that P. mirabilis could synthesize 2-phenylethanol via the Ehrlich pathway under anaerobic conditions. This study reveals the multipath synthetic metabolism for 2-phenylethanol in P. mirabilis and will enrich the new ideas for natural (2-PE) synthesis.

The unique structure of bacterial polysaccharides - Immunochemical studies on the O-antigen of Proteus penneri 4034-85 clinical strain classified into a new O83 Proteus serogroup

The serological classification scheme of the opportunistic Proteus bacilli includes a number of Proteus penneri strains. The tested P. penneri 4034-85 strain turned out to be serologically distinguished in ELISA and Western blotting. The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of this strain and studied by sugar and methylation analyses and dephosphorylation along with ¹H and ¹³C NMR spectroscopy, including 2D ¹H,¹H COSY, TOCSY, ROESY, ¹H,¹³C HSQC, HMBC, and HSQC-TOCSY experiments, The O-polysaccharide was found to have a linear repeating unit containing glycerol 1-phosphate and two residues each of Gal and GlcNAc. The following O-polysaccharide structure was established, which, to our knowledge, is unique among known bacterial polysaccharide structures.

Isolation, nucleotide sequencing and genomic comparison of a Novel SXT/R391 ICE mobile genetic element isolated from a municipal wastewater environment

Integrative Conjugative Elements (ICE’s) of the SXT/R391 family have largely been detected in clinical or environmental isolates of Gammaproteobacteria, particularly Vibrio and Proteus species. As wastewater treatment plants accumulate a large and diverse number of such species, we examined raw water samples taken from a municipal wastewater treatment plant initially using SXT/R391 family integrase gene-specific PCR probes to detect the presence of such elements in a directed approach. A positive amplification occurred over a full year period and a subsequent Restriction Fragment Length Polymorphism (RFLP) analysis revealed a very limited diversity in the treatment plant examined. Samples demonstrating positive amplification were cultured using Vibrio and Proteus selective media and PCR amplification tracking was utilized to monitor SXT/R391-ICE family containing strains. This screening procedure resulted in the isolation and identification of a Proteus mirabilis strain harbouring an ICE. Whole-genome sequencing of this ICE containing strain using Illumina sequencing technology revealed a novel 81 kb element that contained 75 open reading frames on annotation but contained no antibiotic or metal resistance determinants. Comparative genomics revealed the element contained a conserved ICE core with one of the insertions containing a novel bacteriophage defence mechanism. This directed isolation suggests that ICE elements are present in the environment without apparent selective pressure but may contain adaptive functions allowing survival in particular environments such as municipal wastewater which are reservoirs for large bacterial phage populations.

Effects of Cefazolin and Meropenem in Eradication Biofilms of Clinical and Environmental Isolates of Proteus mirabilis

Proteus mirabilis is an opportunistic Gram-negative bacterium belonging to the family Enterobacteriaceae and is known for its ability to cause urinary tract infections. The aim of this study was to determine the value of the minimum concentration of cefazolin and meropenem on biofilm eradication, as well as the resistance profiles and genetic diversity of clinical and environmental isolates of P. mirabilis. We compared the isolates collected from a hospital environment and from an urban stream impacted in Recife-Pernambuco, Brazil. Biochemical tests were performed to determine the profiles of susceptibility, hydrophobicity, biofilm formation and eradication. The genetic diversity was verified using the ERIC-PCR method. The results revealed that two clinical isolates (ICP4 and ICP5) were multi-drug resistant, whereas the environmental isolates showed resistance only to tetracycline, except for CP₅25S, which was resistant also to ampicillin. Of the isolates investigated, three were moderately hydrophobic, while the remaining were hydrophilic. Genetic diversity analysis verified the presence of clones indicating that the stream is harboring and disseminating bacteria of hospital origin. All isolates formed a biofilm, however, high concentrations of cefazolin and meropenem were required to eradicate the already formed biofilm. Our study analyzed the survival strategies of these bacteria in the environments investigated and corresponds to first report the use of these antibiotics to eliminate P. mirabilis biofilms.

Culture Methods for Proteus mirabilis

Proteus mirabilis is generally easy to culture, but its tendency to swarm on a wide variety of media can interfere with isolation of single colonies or identification of other species in a sample. Therefore, specialized media may be needed to control swarming or to study the bacteria under chemically defined conditions. Here, methods are described for routine culture of P. mirabilis, isolation of P. mirabilis from mixed cultures, and culture of P. mirabilis on physiologically relevant media.

Significance and roles of synonymous codon usage in the evolutionary process of Proteus

Proteus spp. bacteria frequently serve as opportunistic pathogens that can infect many animals and show positive survival and existence in various natural environments. The evolutionary pattern of Proteus spp. is an unknown topic, which benefits understanding the different evolutionary dynamics for excellent bacterial adaptation to various environments. Here, the eight whole genomes of different Proteus species were analyzed for the interplay between nucleotide usage and synonymous codon usage. Although the orthologous average nucleotide identity and average nucleotide identity display the genetic diversity of these Proteus species at the genome level, the principal component analysis further shows that these species sustain the specific genetic niche at the aspect of synonymous codon usage patterns. Interestingly, although these Proteus species have A/T rich genes with underrepresented G (guanine) or C (cytosine) at the third codon positions and overrepresented A or T at these positions, some synonymous codons with A or T end are obviously suppressed in usage. The overall codon usage pattern reflected by the effective number of codons (ENC) has a significantly positive correlation with GC3 content (GC content at the third codon position), and ENC has a significantly negative correlation with the adaptation index for these species. These results suggest that the mutation pressure caused by nucleotide composition constraint serves as a dominant evolutionary dynamic driving evolutionary trend of Proteus spp., along with other selections related to natural selection, replication and fine-tune translation, and so on. Taken together, the analyses help to understand the evolutionary interplay between nucleotide and codon usage at the gene level of Proteus.

Frequency and Antimicrobial Resistance Patterns of Bacterial Species Isolated from the Body Surface of the Housefly (Musca domestica) in Akure, Ondo State, Nigeria

BACKGROUND

The emergence and spread of antibiotic resistant bacteria has become a serious problem worldwide. Houseflies are potential carriers of pathogenic and resistant bacteria and could be contributing to the global spread of these strains in the environments. We investigated the prevalence and antimicrobial resistant profiles of bacteria isolated from houseflies in Akure.

METHODS

Twenty-five houseflies were captured by a sterile nylon net from the slaughterhouse, garbage dump, human house, hospital, and eatery from 9:00am to 1:00pm when the flies were active and transported immediately to the laboratory in sterile containers for processing. Bacterial loads were enumerated by serial dilution and plating on nutrient agar and selective media. Bacteria species were isolated by conventional isolation technique. Antibiotic susceptibility test was determined by the Kirby-Bauer disc diffusion technique.

RESULTS

Sixty-seven bacterial species were isolated from 25 samples that were collected. The predominant bacterial species was Escherichia coli (n= 31, 45%), followed by Klebsiella pneumoniae (n= 17, 25%), Staphylococcus aureus (n= 11, 16%) and Pseudomonas aeruginosa (n= 3, 4.3%). The bacterial load of the samples ranged from 9.7×105CFU/mL to 1.65×106CFU/mL. The results revealed that all isolates of Pseudomonas aeruginosa, Salmonella spp, and Proteus mirabilis were resistant to streptomycin and cotrimoxazole, augmentin and amoxicillin respectively. None of the S. aureus isolates was resistant to cotrimoxazole, chloramphenicol, sparfloxacin, augmentin, and ofloxacin. All isolates were multi-drug resistant.

CONCLUSION

House flies that were collected from the slaughterhouse, garbage dump, human house, hospital, and eatery may participate in the dispersal of pathogenic and resistant bacteria in the study environment.

Comparative genomic analysis of Proteus spp. isolated from tree shrews indicated unexpectedly high genetic diversity

Proteus spp. are commensal gastrointestinal bacteria in many hosts, but information regarding the mutual relationships between these bacteria and their hosts is limited. The tree shrew is an alternative laboratory animal widely used for human disease research. However, little is known about the relationship between Proteus spp. and tree shrews. In this study, the complete genome sequencing method was used to analyse the characteristics of Proteus spp. isolated from tree shrews, and comparative genomic analysis was performed to reveal their relationships. The results showed that 36 Proteus spp. bacteria were isolated, including 34 Proteus mirabilis strains and two Proteus vulgaris strains. The effective rate of sequencing was 93.53%±2.73%, with an average GC content of 39.94%±0.25%. Briefly, 3682.89±90.37, 2771.36±36.01 and 2832.06±42.49 genes were annotated in the NCBI non-redundant nucleotide database (NR), SwissProt database and KEGG database, respectively. The high proportions of macrolide-, vancomycin-, bacitracin-, and tetracycline-resistance profiles of the strains were annotated in the Antibiotic Resistance Genes Database (ARDB). Flagella, lipooligosaccharides, type 1 fimbriae and P fimbriae were the most abundantly annotated virulence factors in the Virulence Factor Database (VFDB). SNP variants indicated high proportions of base transitions (Ts), homozygous mutations (Hom) and non-synonymous mutations (Non-Syn) in Proteus spp. (P<0.05). Phylogenetic analysis of Proteus spp. and other references revealed high genetic diversity for strains isolated from tree shrews, and host specificity of Proteus spp. bacteria was not found. Overall, this study provided important information on characteristics of genome for Proteus spp. isolated from tree shrews.

Bacterial metagenome analysis of Mytilus galloprovincialis collected from Istanbul and Izmir coastal stations of Turkey

Mytilus galloprovincialis is a marine mollusk belonging to the Bivalvia class. It has been distributed largely in Turkish shores and worldwide aquatic environments. Besides being known as an environmental pollution indicator, it is highly consumed as a food and has a high economic value. Due to their nutritional mechanisms by filtering water, they are affected by pollution in seawater and mussels can host-microbial diversity of environmental origin as well as pathogenic bacteria. Therefore, in this study, bacterial species found in Mediterranean mussels collected from the coastal stations of Istanbul [Rumeli Kavagi (RK), Kucukcekmece (KC)], and Izmir [(Foca (MF), Urla (MU)] were investigated and compared with microbiological and metagenomic analyses. According to microbiological analysis results, 34 mussel-associated Enterobacteriaceae and Vibrionaceae family members were identified. As a result of the culture-independent metagenomic analysis, taxonomic groups for each station were identified and compared based on Operational Taxonomic Unit data. For all stations, the most abundant bacterial genera were the unclassified bacterial genera. The total number of mussel-related total richness identified in all groups was 4889 (RK = 1605; KC = 1930; MF = 1508; and MU = 1125). According to the metagenomic data obtained in this study, different relative amounts of Lachnospiraceae and Bacteroidetes taxa groups were reported for all stations. The pathogenic bacterial genera identified by metagenomic analyses which may be significant for the public health are Arcobacter, Clostridium, Aeromonas, Vibrio, Escherichia_Shigella, Klebsiella, Campylobacter, Helicobacter, Pseudomonas, Morganella, Serratia, Corynebacterium, Enterococcus, Staphylococcus, Yersinia, Mycoplasma, Brucellaceae_unclassified, Pantoea, and Proteus.

Proteus mirabilis causing cellulitis in broiler chickens

Given the need to understand the virulence profile of Proteus mirabilis isolates from cellulitis in broiler chickens and their ability to cause lesions, the present study aimed to characterize genotypically and phenotypically the virulence profiles of two strains of P. mirabilis isolated from cellulitis in broilers, as well as to evaluate their ability to experimentally reproduce the lesions in vivo. The strain with the highest virulence potential (LBUEL-A33) possessed mrpA, pmfA, ucaA, atfA (fimbriae), zapA, ptA (proteases), hpmA (hemolysin), and ireA (siderophore) genes, formed a very strong biofilm, and expressed the pattern of aggregative adhesion and cytotoxicity in Vero cells. The strain with the lowest virulence potential (LBUEL-A34) did not present the pmfA and ucaA genes, but expressed the pattern of aggregative adhesion, formed a strong biofilm, and did not show cytotoxicity. Both strains developed cellulitis in an animal model within 24 h post-inoculation (PI), and the degree of lesions was not significantly altered up to 120 h PI. The LBUEL-A33 strain was also inoculated in combination with an avian pathogenic Escherichia coli (APEC 046), and the lesions showed no significant changes from the individual inoculation of these two strains. Histological analysis showed that the LBUEL-A33 strain developed characteristic cellulitis lesions. Thus, both strains of P. mirabilis isolated in our study have several virulence factors and the ability to develop cellulitis in broilers.

First-time characterization of viable but non-culturable Proteus mirabilis: Induction and resuscitation

Pathogenic bacteria can enter into a viable but non‐culturable (VBNC) state under unfavourable conditions. Proteus mirabilis is responsible for dire clinical consequences including septicaemia, urinary tract infections and pneumonia, but is not a species previously known to enter VBNC state. We suggested that stress‐induced P. mirabilis can enter a VBNC state in which it retains virulence. P. mirabilis isolates were incubated in extreme osmotic pressure, starvation, low temperature and low pH to induce a VBNC state. Resuscitation was induced by temperature upshift and inoculation in tryptone soy broth with Tween 20 and brain heart infusion broth. Cellular ultrastructure and gene expression were examined using transmission electron microscopy (TEM) and quantitative real‐time polymerase chain reaction (qPCR), respectively. High osmotic pressure and low acidity caused rapid entry into VBNC state. Temperature upshift caused the highest percentage of resuscitation (93%) under different induction conditions. In the VBNC state, cells showed aberrant and dwarf morphology, virulence genes and stress response genes (envZ and rpoS) were expressed (levels varied depending on strain and inducing factors). This is the first‐time characterization of VBNC P. mirabilis. The ability of P. mirabilis pathogenic strains to enter a stress‐induced VBNC state can be a serious public health threat.

Differences in plant metabolites and microbes associated with Azadirachta indica with variation in air pollution

Mitigation of air pollution by plants is a well-established phenomenon. Trees planted on the roadside are known to reduce particulate matter pollution by about 25%. In an urban ecosystem, especially in a metropolitan city such as Delhi, roadside trees are constantly exposed to air pollution. We, therefore, evaluated the effect of air pollution on a common Indian roadside tree, Neem (Azadirachta indica), and its associated microbes in areas with high and low levels of particulate matter (PM) pollution in Delhi. We hypothesized that alteration in the air quality index not only influences plant physiology but also its microbiome. A 100-fold increase in the number of epiphytic and 10-100 fold increase in endophytic colonies were found with 1.7 times increase in the level of pollutants. Trees in the polluted areas had an abundance of Salmonella, Proteus and Citrobacter, and showed increased secondary metabolites such as phenols and tannins as well as decreased chlorophyll and carotenoid. The number of unique microbes was positively correlated with increased primary metabolites. Our study thus indicates that, alteration in air quality affects the natural micro-environment of plants. These results may be utilized as sustainable tools for studying plant adaptations to the urban ecosystem.

Genomic and functional characterization of fecal sample strains of Proteus cibarius carrying two floR antibiotic resistance genes and a multiresistance plasmid-encoded cfr gene

The objective of this study was to investigate the molecular characteristics and horizontal transfer of florfenicol resistance gene-related sequences in Proteus strains isolated from animals. A total of six Proteus strains isolated from three farms between 2015 and 2016 were screened by polymerase chain reaction (PCR) for known florfenicol resistance genes. Proteus cibarius G11, isolated from the fecal material of a goose, was found to harbor both cfr and floR genes. Whole genome sequencing revealed that the strain harbored two copies of the floR gene: one was located on the chromosome and the other was located on a plasmid named pG11-152. Two floR-containing fragments 4028 bp in length were identical and showed transposon-like structures. The cfr gene was found on a plasmid named pG11-51 and flanked by a pair of IS26s. Thus, mobile genetic elements played an important role in floR replication and horizontal resistance gene transfer. Therefore, increasing attention should be paid to monitoring the spread of resistance genes and resistance in real time.

Second generation effects of larval metal pollutant exposure on reproduction, longevity and insecticide tolerance in the major malaria vector Anopheles arabiensis (Diptera: Culicidae)

Background

Members of the Anopheles gambiae complex breed in clean, sunlit temporary bodies of water. Anthropogenic pollution is, however, altering the breeding sites of the vectors with numerous biological effects. Although the effects of larval metal pollution have previously been examined, this study aims to assess the transgenerational effects of larval metal pollution on the major malaria vector An. arabiensis.

Methods

Two laboratory strains of An. arabiensis, SENN (insecticide-susceptible) and SENN-DDT (insecticide-resistant), were used in this study. After being bred in water polluted with either cadmium chloride, copper nitrate or lead nitrate, several life history characteristics that can have epidemiological implications (fertility, apoptotic damage to reproductive structures, adult longevity and insecticide tolerance) were examined in the adults and compared to those of adults bred in clean water.

Results

All metal treatments reduced fecundity in SENN, but only lead treatment reduced fertility in SENN-DDT. Cadmium chloride exposure resulted in apoptosis and deformation of the testes in both strains. After breeding generation F0 in polluted water, F1 larvae bred in clean water showed an increase in longevity in SENN-DDT adult females. In contrast, after breeding the F0 generation in polluted water, longevity was reduced after cadmium and copper exposure in the F1 generation. Larval metal exposure resulted in an increase in insecticide tolerance in adults of the SENN strain, with SENN-DDT adults gaining the greatest fold increase in insecticide tolerance.

Conclusions

This study demonstrates that a single exposure to metal pollution can have transgenerational effects that are not negated by subsequent breeding in clean water.

Potential of a fly gut microbiota incorporated gel-based larval diet for rearing Bactrocera dorsalis (Hendel)

Background

The Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an important polyphagous pest of horticultural produce. The sterile insect technique (SIT) is a proven control method against many insect pests, including fruit flies, under area-wide pest management programs. High quality mass-rearing process and the cost-effective production of sterile target species are important for SIT. Irradiation is reported to cause severe damage to the symbiotic community structure in the mid gut of fruit fly species, impairing SIT success. However, studies have found that target-specific manipulation of insect gut bacteria can positively impact the overall fitness of SIT-specific insects.

Results

Twelve bacterial genera were isolated and identified from B. dorsalis eggs, third instars larval gut and adults gut. The bacterial genera were Acinetobacter, Alcaligenes, Citrobacter, Pseudomonas, Proteus, and Stenotrophomonas, belonging to the Enterobacteriaceae family. Larval diet enrichment with the selected bacterial isolate, Proteus sp. was found to improve adult emergence, percentage of male, and survival under stress. However, no significant changes were recorded in B. dorsalis egg hatching, pupal yield, pupal weight, duration of the larval stage, or flight ability.

Conclusions

These findings support the hypothesis that gut bacterial isolates can be used in conjunction with SIT. The newly developed gel-based larval diet incorporated with Proteus sp. isolates can be used for large-scale mass rearing of B. dorsalis in the SIT program.

Occurrence, Genetic Diversities And Antibiotic Resistance Profiles Of Salmonella Serovars Isolated From Chickens

Purpose

Contamination with Salmonella on food products and poultry in particular has been linked to foodborne infections and/or death in humans. This study investigated the occurrence, genetic diversities and antibiotic resistance profiles of Salmonella strains isolated from chickens.

Patients and methods

Twenty each duplicate faecal swab samples were collected from five different poultry pens of broilers, layers and indigenous chickens in the North-West Province, South Africa. Isolates identities were confirmed through amplification and sequence analysis of 16S rRNA and the invA gene fragments after which phylogenetic tree was constructed. Salmonella enteritidis (ATCC:13076^TM), Salmonella Typhimurium (ATCC:14028^TM) and E. coli (ATCC:259622^TM) were used as positive and negative controls, respectively. The serotypes of Salmonella isolates were determined. Antibiotic-resistant profiles of the isolates against eleven antimicrobial agents were determined.

Results

Eighty-four (84%) of representative isolates possessed the invA genes. The percent occurrence and diversity of Salmonella subspecies in chickens were 1.81-30.9% and was highest in Salmonella enterica subsp. enterica. Notably, the following serotypes Salmonella bongori (10.09%), Salmonella Pullorum (1.81%), Salmonella Typhimurium (12.72%), Salmonella Weltevreden, Salmonella Chingola, Salmonella Houten and Salmonella Bareily (1.81%). Isolates (96.6%) displayed multidrug resistance profiles and the identification of isolates with more than nine antibiotic resistance was a cause for concern.

Conclusion

This study indicates that isolates had pre-exposure histories to the antibiotics tested and may pose severe threats to food security and public health.

Complete Genome Sequence of Proteus mirabilis Siphophage Saba

Proteus mirabilis is a Gram-negative enteric bacterium associated with complicated human urinary tract infections. Here, we present the complete genome annotation for P. mirabilis siphophage Saba. With a 60,056-bp genome and 75 predicted genes, Saba is most similar at the nucleotide and protein levels to phage Chi and Chi-like viruses.

Structural and serological characterization of the O82 antigen of a Proteus mirabilis strain isolated from a patient in Poland

P. mirabilis strains Kro 45 and Kwy 46 were isolated from the pus and the muscular fluid, respectively, of a hospitalized 61-year-old female in Łódź, Poland. Both strains demonstrated a good swarming ability on a solid medium, and the Dienes test for differentiation of swarming strains indicated their identity. The strains were serologically identical and did not belong to any of the known Proteus O1-O81 serogroups. In this work, we studied the O-specific polysaccharide (O antigen) of P. mirabilis Kwy46, which defines the immunospecificity of the strain. The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide, and the following structure of its oligosaccharide repeat (O-unit) was established by sugar analysis along with 1D and 2D ¹H and ¹³C NMR spectroscopy: where (S)-lac indicates an (S)-1-carboxyethyl group [an (S)-lactic acid residue], which forms an ether with a GlcNAc residue (so called glycolactilic acid). This structure is unique among Proteus O-polysaccharides but shares a trisaccharide fragment with that of P. mirabilis O5. Studies of the cross-reactivity between P. mirabilis Kwy 46 O antiserum/lipopolysaccharide and Proteus O1-O81 lipopolysaccharides/O antisera allowed identification of a putative Kwy 46 O-antigen epitope. Based on the data obtained, it is proposed to create a new O82 serogroup within the genus Proteus represented by the studied P. mirabilis isolates.

The characteristics of gut microbiota and commensal Enterobacteriaceae isolates in tree shrew (Tupaia belangeri)

BACKGROUND

Tree shrew is a novel laboratory animal with specific characters for human disease researches in recent years. However, little is known about its characteristics of gut microbial community and intestinal commensal bacteria. In this study, 16S rRNA sequencing method was used to illustrate the gut microbiota structure and commensal Enterobacteriaceae bacteria were isolated to demonstrate their features.

RESULTS

The results showed Epsilonbacteraeota (30%), Proteobacteria (25%), Firmicutes (19%), Fusobacteria (13%), and Bacteroidetes (8%) were the most abundant phyla in the gut of tree shrew. Campylobacteria, Campylobacterales, Helicobacteraceae and Helicobacter were the predominant abundance for class, order, family and genus levels respectively. The alpha diversity analysis showed statistical significance (P < 0.05) for operational taxonomic units (OTUs), the richness estimates, and diversity indices for age groups of tree shrew. Beta diversity revealed the significant difference (P < 0.05) between age groups, which showed high abundance of Epsilonbacteraeota and Spirochaetes in infant group, Proteobacteria in young group, Fusobacteria in middle group, and Firmicutes in senile group. The diversity of microbial community was increased followed by the aging process of this animal. 16S rRNA gene functional prediction indicated that highly hot spots for infectious diseases, and neurodegenerative diseases in low age group of tree shrew (infant and young). The most isolated commensal Enterobacteriaceae bacteria from tree shrew were Proteus spp. (67%) and Escherichia coli (25%). Among these strains, the antibiotic resistant isolates were commonly found, and pulsed-field gel electrophoresis (PFGE) results of Proteus spp. indicated a high degree of similarity between isolates in the same age group, which was not observed for other bacteria.

CONCLUSIONS

In general, this study made understandings of the gut community structure and diversity of tree shrew.

Hole-in-the-head disease in discus fish, Symphysodon (Heckel, 1840): Is it a consequence of a dietary Ca/P imbalance?

Hole-in-the-head (HITH) disease-affected fish develop characteristic lesions in the skin above sensory pores of the head and the trunk. This study investigated whether an unfavourable Ca/P ratio in the diet could provoke lesions consistent with HITH disease in discus fish Symphysodon (Heckel, 1840) as a comparable condition to secondary hyperparathyroidism of tetrapod species. Two groups of five fish were fed a plain beef heart diet (Ca/P of 0.03), whereas two other groups were kept on commercial discus feed (Ca/P of 2.73). Each feeding group was submitted to two different water hardness regimes (35.66-71.39 mg/L CaCO₃ and 124.94-196.33 mg/L CaCO₃ , respectively). All fish were observed for the development of the characteristic lesions for 16 weeks. At the end of the study, histological, bacteriological and parasitological examinations were conducted and plasma Ca, P and Mg values were determined. Diplomonad flagellates were detected in two fish. Isolated bacteria of all groups mostly belonged to Aeromonadales and Pseudomonadales. No significant difference of plasma mineral values between the groups was observed. Compared to the results of other authors, Ca stayed mainly in the range and P exceeded the reference values. Histological examinations did not indicate HITH disease, and no fish developed signs of the disease during the study. Clinical trial registration number GZ 68.205/0135-WF/V/36/2014.

Genotypic and phenotypic profiles of virulence factors and antimicrobial resistance of Proteus mirabilis isolated from chicken carcasses: potential zoonotic risk

Proteus mirabilis is an opportunistic pathogen often associated with a variety of human infections acquired both in the community and in hospitals. In this context, the present work aimed to evaluate the genotypic and phenotypic characteristics of the virulence factors and antimicrobial resistance determinants of 32 P. mirabilis strains isolated from chicken carcasses in a poultry slaughterhouse in the north of the state of Paraná, Brazil, in order to assess a potential zoonotic risk. The isolates presented a variety of virulence genes that contribute to the development of infection in humans. The mrpA, pmfA, atfA (fimbriae), ireA (siderophores receptor), zapA, ptA (Proteases), and hpmA (hemolysin) genes were found in 32 (100%) isolates and ucaA (fimbriae) in 16 (50%). All isolates showed aggregative adherence in HEp-2 cells and formed biofilms. Of all strains, 27 (84.38%) showed cytotoxic effects in Vero cells. Antimicrobial susceptibility was tested using 20 antimicrobials, in which 25 (78.13%) strains were considered multidrug-resistant. The presence of blaESBL and blaampC genes conferring resistance to β-lactams and qnr to quinolones were also detected in the isolates after presumption in the phenotypic test, in which 7 (21.88%) isolates contained the CTX-M-2 group, 11 (34.38%) contained CIT group and 19 (59.38%) contained qnrD. Therefore, chicken carcasses contaminated with P. mirabilis may pose a health risk to the consumer, as these isolates have a variety of virulence and antimicrobial resistance characteristics that can be found in P. mirabilis strains isolated from human infections.

Conventional and Specific-Pathogen Free Rats Respond Differently to Anesthesia and Surgical Trauma

Specific-pathogen free (SPF) animals were introduced in the 1960s to minimize disease and infection as variables in biomedical research. Our aim was to examine differences in physiological response in rat colonies bred and housed in a conventional versus SPF facility, and implications for research. Sprague-Dawley rats were anesthetized and catheterized for blood and pressure monitoring, and electrocardiogram (ECG) leads implanted. Hematology was assessed, and coagulation profile using rotational thromboelastometry. Health screening was outsourced to Cerberus Sciences. SPF rats had significantly lower pulse pressure (38% decrease), arrhythmias and prolonged QTc (27% increase) compared to conventional rats. No arrhythmias were found in conventional rats. SPF rats had significantly higher white cell, monocyte, neutrophil and lymphocyte counts, and were hyperfibrinolytic, indicated by EXTEM maximum lysis >15%. Independent assessment revealed similar pathogen exclusion between colonies, with the exception of Proteus in SPF animals. Returning to a conventional facility restored normal host physiology. We conclude that SPF animals displayed an abnormal hemodynamic, hematological and hemostatic phenotype in response to anesthesia and surgery, and provide a number of recommendations to help standardize research outcomes and translation.

Primary and Secondary Bacteremia Caused by Proteus spp.: Epidemiology, Strains Susceptibility and Biofilm Formation

Proteus spp. is an etiological factor of urinary tract and bloodstream infections. The aim of this study was the retrospective analysis of susceptibility of Proteus spp. strains isolated from bloodstream infections (BSIs) as well as similarity evaluation of the strains isolated from different clinical samples. Proteus spp. strains were isolated in 2009-2017 from hospital patients. Identification was based on the colony's morphology and biochemical or MALDI-TOF MS analyzes. The antibiotic susceptibility test was done using the diffusion method. Biofilm formation was evaluated with microplate method using TTC. Bacteremia caused by Proteus spp. was found in 97 patients, mainly secondary to urinary tract infection. Most of the strains were susceptible to piperacillin with tazobactam (95.9%) and amikacin (86.7%). Elderly patients have a higher risk of mortality after BSIs caused by Proteus spp. A detailed analysis was made for randomly chosen 26 strains isolated from 11 patients with Proteus mirabilis bacteremia. Using PFGE, we found that 10 (90.9%) isolates, collected from different clinical specimens of the same patient, were genetically identical.

Proteus spp. is an etiological factor of urinary tract and bloodstream infections. The aim of this study was the retrospective analysis of susceptibility of Proteus spp. strains isolated from bloodstream infections (BSIs) as well as similarity evaluation of the strains isolated from different clinical samples. Proteus spp. strains were isolated in 2009–2017 from hospital patients. Identification was based on the colony’s morphology and biochemical or MALDI-TOF MS analyzes. The antibiotic susceptibility test was done using the diffusion method. Biofilm formation was evaluated with microplate method using TTC. Bacteremia caused by Proteus spp. was found in 97 patients, mainly secondary to urinary tract infection. Most of the strains were susceptible to piperacillin with tazobactam (95.9%) and amikacin (86.7%). Elderly patients have a higher risk of mortality after BSIs caused by Proteus spp. A detailed analysis was made for randomly chosen 26 strains isolated from 11 patients with Proteus mirabilis bacteremia. Using PFGE, we found that 10 (90.9%) isolates, collected from different clinical specimens of the same patient, were genetically identical.

The Current Evidence on the Association Between the Urinary Microbiome and Urinary Incontinence in Women

Urinary incontinence (UI) is a burdensome condition with high prevalence in middle-aged to older women and an unclear etiology. Advances in our understanding of host-microbe interactions in the urogenital tract have stimulated interest in the urinary microbiome. DNA sequencing and enhanced urine culture suggest that similarly to other mucosal sites, the urinary bladder of healthy individuals harbors resident microbial communities that may play distinct roles in bladder function. This review focused on the urobiome (expanded quantitative urine culture-based or genomic sequencing-based urinary microbiome) associated with different subtypes of UI, including stress, urgency and mixed urinary incontinence, and related syndromes, such as interstitial cystitis and overactive bladder in women, contrasted to urinary tract infections. Furthermore, we examined clinical evidence for the association of the urinary microbiome with responses to pharmacotherapy for amelioration of UI symptoms. Although published studies are still relatively limited in number, study design and sample size, cumulative evidence suggests that certain Lactobacillus species may play a role in maintaining a healthy bladder milieu. Higher bacterial diversity in the absence of Lactobacillus dominance was associated with urgency UI and resistance to anticholinergic treatment for this condition. UI may also facilitate the persistence of uropathogens following antibiotic treatment, which in turn can alter the commensal/potentially beneficial microbial communities. Risk factors of UI, including age, menopausal status, sex steroid hormones, and body mass index may also impact the urinary microbiome. However, it is yet unclear whether the effects of these risks factors on UI are mediated by urinary host-microbe interactions and a mechanistic link with the female urogenital microbiome is still to be established. Strategies for future research are suggested.

Proteus faecis sp. nov., and Proteus cibi sp. nov., two new species isolated from food and clinical samples in China

Eight swarming motile bacteria were isolated from food and clinical samples in China. Cells were Gram-stain-negative, facultatively anaerobic and rod-shaped (0.5-0.8×1.0-3.0 μm) with hairlike pili and flagella. The 16S rRNA and partial rpoB housekeeping gene sequence analyses indicated that the strains belong to the genus Proteusin the family Enterobacteriaceae. Of the eight strains studied, seven and a single isolate formed two separate clades in the phylogeny of Proteusspecies, indicating two separate species. Both the in silico DNA-DNA hybridization and the average nucleotide identity values between these two groups and to the type strains of the genus Proteuswere below the recommended threshold for signifying their candidature as two separate species. The DNA G+C contents of strains TJ1636^T and FJ2001126-3^T were 37.8 and 38.1 mol%, respectively. The major cellular fatty acids of the two novel type strains were C16:0, cyclo C17:0, summed feature 3 and summed feature 8. The results supported that the strains belong to different taxonomic positions in the genus Proteus. The isolates were named Proteus faecis sp. nov., with type strain TJ1636^T (=DSM 106180^T=GDMCC 1.1245^T), and Proteuscibi sp. nov., with type strain FJ2001126-3^T (=DSM 106178^T =GDMCC 1.1244^T).

Analysis of Proteus mirabilis Social Behaviors on Surfaces

The opportunistic pathogen Proteus mirabilis engages in visually dramatic and dynamic social behaviors. Populations of P. mirabilis can rapidly occupy surfaces, such as high-percentage agar and latex, through a collective surface-based motility termed swarming. When in these surface-occupying swarm colonies, P. mirabilis can distinguish between clonal siblings (self) and foreign P. mirabilis strains (nonself). This ability can be assessed by at least two standard methods: boundary formation, aka a Dienes line, and territorial exclusion. Here we describe methods for quantitative analysis of swarm colony expansion, of boundary formation, and of territorial exclusion. These assays can be employed to assess several aspects of P. mirabilis sociality including collective swarm motility, competition, and self versus nonself recognition.

Longitudinal Microbiome Composition and Stability Correlate with Increased Weight and Length of Very-Low-Birth-Weight Infants

The microbiomes of 83 preterm very-low-birth-weight (VLBW) infants and clinical covariates were analyzed weekly over the course of their initial neonatal intensive care unit (NICU) stay, with infant growth as the primary clinical outcome. Birth weight significantly correlated with increased rate of weight gain in the first 6 weeks of life, while no significant relationship was observed between rate of weight gain and feeding type. Microbial diversity increased with age and was significantly correlated with weight gain and percentage of the mother's own milk. As expected, infants who received antibiotics during their NICU stay had significantly lower alpha diversity than those who did not. Of those in the cohort, 25 were followed into childhood. Alpha diversity significantly increased between NICU discharge and age 2 years and between age 2 years and age 4 years, but the microbial alpha diversity of 4-year-old children was not significantly different from that of mothers. Infants who showed improved length over the course of their NICU stay had significantly more volatile microbial beta diversity results than and a significantly decreased microbial maturity index compared with infants who did not; interestingly, all infants who showed improved length during the NICU stay were delivered by Caesarean section. Microbial beta diversity results were significantly different between the time of the NICU stay and all other time points (for children who were 2 or 4 years old and mothers when their children were 2 or 4 years old). IMPORTANCE Preterm infants are at greater risk of microbial insult than full-term infants, including reduced exposure to maternal vaginal and enteric microbes, higher rates of formula feeding, invasive procedures, and administration of antibiotics and medications that alter gastrointestinal pH. This investigation of the VLBW infant microbiome over the course of the neonatal intensive care unit (NICU) stay, and at ages 2 and 4 years, showed that the only clinical variables associated with significant differences in taxon abundance were weight gain during NICU stay (Klebsiella and Staphylococcus) and antibiotic administration (Streptococcus and Bifidobacterium). At 2 and 4 years of age, the microbiota of these VLBW infants became similar to the mothers' microbiota. The number of microbial taxa shared between the infant or toddler and the mother varied, with least the overlap between infants and mothers. Overall, there was a significant association between the diversity and structure of the microbial community and infant weight and length gain in an at-risk childhood population.

Selenium Nanoparticle Synthesized by Proteus mirabilis YC801: An Efficacious Pathway for Selenite Biotransformation and Detoxification

Selenite is extremely biotoxic, and as a result of this, exploitation of microorganisms able to reduce selenite to non-toxic elemental selenium (Se⁰) has attracted great interest. In this study, a bacterial strain exhibiting extreme tolerance to selenite (up to 100 mM) was isolated from the gut of adult Monochamus alternatus and identified as Proteus mirabilis YC801. This strain demonstrated efficient transformation of selenite into red selenium nanoparticles (SeNPs) by reducing nearly 100% of 1.0 and 5.0 mM selenite within 42 and 48 h, respectively. Electron microscopy and energy dispersive X-ray analysis demonstrated that the SeNPs were spherical and primarily localized extracellularly, with an average hydrodynamic diameter of 178.3 ± 11.5 nm. In vitro selenite reduction activity assays and real-time PCR indicated that thioredoxin reductase and similar proteins present in the cytoplasm were likely to be involved in selenite reduction, and that NADPH or NADH served as electron donors. Finally, Fourier-transform infrared spectral analysis confirmed the presence of protein and lipid residues on the surfaces of SeNPs. This is the first report on the capability of P. mirabilis to reduce selenite to SeNPs. P. mirabilis YC801 might provide an eco-friendly approach to bioremediate selenium-contaminated soil/water, as well as a bacterial catalyst for the biogenesis of SeNPs.

BACTERIA PRESENT IN SCARLET IBIS (Eudocimus ruber) CHICKS, BABITONGA BAY, SANTA CATARINA STATE, BRAZIL

Abstract Wild birds are important for public health because of their potential to transmit pathogenic microorganisms to humans. The waterbird scarlet ibis (Eudocimus ruber) forages and breeds near urban areas and if they settle near polluted waters, the viability of adults and their young can be negatively affected. Hence, the aim of this study was to evaluate the cloacal aerobic bacteria profile of nestling scarlet ibis in a mixed colony in Jarivatuba Island, in Joinville, Santa Catarina, Brazil. Cloacal swab samples were collected from clinically normal scarlet ibis nestlings during the breeding season of 2015/2016 (n=16) and 2016/2017 (n=34), and plated onto blood, MacConkey, and Salmonella-Shigella agar plates. Escherichia coli, Proteus vulgaris, Proteus spp., Klebsiella sp., Enterococcus spp. and Staphylococcus spp. were isolated and may be representative of the normal microbiota of E. ruber, although the normal profile is unknown for the species. However, the location of this colony in an area without adequate sewage treatment, which receives domestic effluents, may indicate a modified bacterial profile. Further studies are needed, to better understand the host's natural microbiome, as well as on the bacterial isolates, in order to characterize any association with the contaminated water. These results lay the foundation for successful species conservation projects in the area by providing insights that will help improve the viability of nestlings in each reproductive season.

A Metagenomic Approach to Evaluating Surface Water Quality in Haiti

The cholera epidemic that occurred in Haiti post-earthquake in 2010 has resulted in over 9000 deaths during the past eight years. Currently, morbidity and mortality rates for cholera have declined, but cholera cases still occur on a daily basis. One continuing issue is an inability to accurately predict and identify when cholera outbreaks might occur. To explore this surveillance gap, a metagenomic approach employing environmental samples was taken. In this study, surface water samples were collected at two time points from several sites near the original epicenter of the cholera outbreak in the Central Plateau of Haiti. These samples underwent whole genome sequencing and subsequent metagenomic analysis to characterize the microbial community of bacteria, fungi, protists, and viruses, and to identify antibiotic resistance and virulence associated genes. Replicates from sites were analyzed by principle components analysis, and distinct genomic profiles were obtained for each site. Cholera toxin converting phage was detected at one site, and Shiga toxin converting phages at several sites. Members of the Acinetobacter family were frequently detected in samples, including members implicated in waterborne diseases. These results indicate a metagenomic approach to evaluating water samples can be useful for source tracking and the surveillance of pathogens such as Vibrio cholerae over time, as well as for monitoring virulence factors such as cholera toxin.

In vitro anti-inflammatory and antimicrobial potential of leaf extract from Artemisia nilagirica (Clarke) Pamp

In the present investigation, the bioactive compounds from the leaf extract of Artemisia nilagirica showed potent anti-inflammatory and antimicrobial activity. The leaf extract showed a maximum protection of human red blood cells (HRBC) with 74.63% at 20 µg/mL concentration, and the minimum hemolysis was 25.37% in a hypotonic solution with diclofenac as the control. The in vitro antimicrobial activity of plant extract against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Proteus vulgaris, Yersinia enterocolitica, Bacillus subtilis, and Candida albicans was evaluated at various concentrations (50, 100, 150, and 200 µg). The maximum zone of inhibition was observed against P. aeruginosa followed by B. subtilis, S. typhi, S. aureus and E. coli. The leaf extract also showed potent activity against C. albicans.

Sensitivity of Entomopathogenic Fungi and Bacteria to Plants Secondary Metabolites, for an Alternative Control of Rhipicephalus (Boophilus) microplus in Cattle

Boophilus (Rhipicephalus) microplus is a one host hard tick widespread in warm climates worldwide, responsible for great economic losses. To avoid resistance in ticks population, induced by the repeated administration of conventional acaricides and/or the presence of residues in the environment in meat and in milk, an alternative approach can be achieved using entomopathogenic microorganisms such as fungi and bacteria, or essential oils (EOs). The aim of the present study was to evaluate the in vitro sensitivity of Beauveria bassiana, Metarhizium anisopliae, Scopulariopsis sp, Bacillus thuringiensis and Proteus mirabilis to Eucalyptus globulus, Lavandula hybrida, Pelargonium graveolens EOs and to their main constituents such as lynalool, linalyl-acetate, geraniol, citronellol and 1,8 cineole. EOs has been chemically characterized by GC-MS. Fungal isolates were tested by a microdilution assay to achieve minimal inhibitory concentration (MIC) of both EOs and main components. The sensitivity of bacteria was evaluated by an agar disk diffusion. The results obtained show the feasibility of an integrate approach for an eco-friendly control of R. microplus by use of both entomopathogenic fungi and P. graveolens EO. L. hybrida could be an interesting alternative when B. bassiana is not employed. Conversely, a combined use of B. thuringiensis and EOs would not be advisable in the integrate control of ticks.

Potential of Bacterial Isolates from a Stream in Manaus-Amazon to Bioremediate Chromium-Contaminated Environments

Igarapé do Quarenta (IgQ), a stream located in the Manaus-AM, BR, has directly experienced the impacts of urban expansion over the last five decades, which contributed for its contamination. As an affluent of Rio Negro, IgQ also affects the water quality of this important river that bathes Manaus. However, the stress caused by the prolonged exposition to chemical agents may have selected microorganisms that exhibit great bioremediation potential. In the present study, bacteria isolated from four distinct sites of the IgQ were identified, and their potential to degrade hexavalent chromium (Cr(VI)) was investigated using the s-diphenylcarbazide method. Among the investigated isolates, 14 exhibited resistance against Cr(VI) at a concentration of 300 mg/L and eight isolates reduced over 50% (53.5-97.4%) chromium ratios after 72 h of incubation. Those isolates were identified by gene sequencing and classified in 10 genera (Acidovorax sp., Acinetobacter sp., Alicycliphilus sp., Bacillus sp., Comamonas sp., Enterobacter sp., Micrococcus sp., Proteus sp., Serratia sp., and Vagococcus sp.). Under control conditions, the isolate of Vagococcus sp. genus, in only 24 h of incubation, reduced 96.8% of the rate of Cr(VI) added to the culture medium at the concentration of 10 mg/L. Obtained results indicate that the Vagococcus sp. exhibits a great potential to be used in the bioremediation of areas contaminated with chromium. The mechanisms of action of microorganisms should be investigated for more specific applications in the decontamination of effluents and direct use of its by-products to bioremediate polluted environments.

Proteus spp. as Putative Gastrointestinal Pathogens

Proteus species, members of the Enterobacteriaceae family, are usually considered commensals in the gut and are most commonly recognized clinically as a cause of urinary tract infections. However, the recent identification of Proteus spp. as potential pathogens in Crohn's disease recurrence after intestinal resection serves as a stimulus to examine their potential role as gut pathogens. Proteus species possess many virulence factors potentially relevant to gastrointestinal pathogenicity, including motility; adherence; the production of urease, hemolysins, and IgA proteases; and the ability to acquire antibiotic resistance. Gastrointestinal conditions that have been linked to Proteus include gastroenteritis (spontaneous and foodborne), nosocomial infections, appendicitis, colonization of devices such as nasogastric tubes, and Crohn's disease. The association of Proteus species with Crohn's disease was particularly strong. Proteus species are low-abundance commensals of the human gut that harbor significant pathogenic potential; further investigation is needed.

Mimicking a New 2-Phenylethanol Production Pathway from Proteus mirabilis JN458 in Escherichia coli

Bacteria rarely produce natural 2-phenylethanol. We verified a new pathway from Proteus mirabilis JN458 to produce 2-phenylethanol using Escherichia coli to coexpress l-amino acid deaminase, α-keto acid decarboxylase, and alcohol dehydrogenase from P. mirabilis. Based on this pathway, a glucose dehydrogenase coenzyme regeneration system was constructed. The optimal conditions of biotransformation by the recombinant strain E-pAEAKaG were at 40 °C and pH 7.0. Finally, the recombinant strain E-pAEAKaG produced 3.21 ± 0.10 g/L 2-phenylethanol in M9 medium containing 10 g/L l-phenylalanine after a 16 h transformation. Furthermore, when the concentration of l-phenylalanine was 4 g/L (24 mM), the production of 2-phenylethanol reached 2.88 ± 0.18 g/L and displayed a higher conversion rate of 97.38 mol %.

Effects of glyphosate herbicide on the gastrointestinal microflora of Hawaiian green turtles (Chelonia mydas) Linnaeus

In Hawaii, glyphosate-based herbicides frequently sprayed near shorelines may be affecting non-target marine species. Glyphosate inhibits aromatic amino acid biosynthesis (shikimate pathway), and is toxic to beneficial gut bacteria in cattle and chickens. Effects of glyphosate on gut bacteria in marine herbivorous turtles were assessed in vitro. When cultures of mixed bacterial communities from gastrointestinal tracts of freshly euthanized green turtles (Chelonia mydas), were exposed for 24h to six glyphosate concentrations (plus deionized water control), bacterial density was significantly lower at glyphosate concentrations≥2.2×10-4gL-1 (absorbance measured at 600nm wavelength). Using a modified Kirby-Bauer disk diffusion assay, the growth of four bacterial isolates (Pantoea, Proteus, Shigella, and Staphylococcus) was significantly inhibited by glyphosate concentrations≥1.76×10-3gL-1. Reduced growth or lower survival of gut bacteria in green turtles exposed to glyphosate could have adverse effects on turtle digestion and overall health.

Changes in the lipopolysaccharide of Proteus mirabilis 9B-m (O11a) clinical strain in response to planktonic or biofilm type of growth

The impact of planktonic and biofilm lifestyles of the clinical isolate Proteus mirabilis 9B-m on its lipopolysaccharide (O-polysaccharide, core region, and lipid A) was evaluated. Proteus mirabilis bacteria are able to form biofilm and lipopolysaccharide is one of the factors involved in the biofilm formation. Lipopolysaccharide was isolated from planktonic and biofilm cells of the investigated strain and analyzed by SDS–PAGE with silver staining, Western blotting and ELISA, as well as NMR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry techniques. Chemical and NMR spectroscopic analyses revealed that the structure of the O-polysaccharide of P. mirabilis 9B-m strain did not depend on the form of cell growth, but the full-length chains of the O-antigen were reduced when bacteria grew in biofilm. The study also revealed structural modifications of the core region in the lipopolysaccharide of biofilm-associated cells—peaks assigned to compounds absent in cells from the planktonic culture and not previously detected in any of the known Proteus core oligosaccharides. No differences in the lipid A structure were observed. In summary, our study demonstrated for the first time that changes in the lifestyle of P. mirabilis bacteria leads to the modifications of their important virulence factor—lipopolysaccharide.

Comparison of virulence genes in Proteus species isolated from human and pet turtle

The current study was aimed to investigate the prevalence of ureC, rsbA, zapA and mrpA virulence genes using polymerase chain reaction (PCR) in Proteus spp. isolated from 5 commercially popular species of pet turtles and comparison of the mrpA gene sequences of Proteus mirabilis isolates with human clinical isolates. A total of 24 isolates in pet turtles were identified, comprised of P. mirabilis (15), Proteus vulgaris (7) and Proteus hauseri (2). The prevalence of ureC, rsbA, zapA and mrpA genes among all identified Proteus spp. isolates were 91.7%, 50%, 45.8% and 45.8%, respectively. The average percentage similarities of mrpA gene sequence of pet turtle P. mirabilis isolates to human urinary and respiratory isolates were 96.35% and 94.85%, respectively. The prevalence of virulence genes and high similarity of mrpA gene sequences between pet turtles and human P. mirabilis isolates revealed that though pet turtles are healthy, these animals may pose a potential risk of urinary and respiratory infections to humans.

Inactivation of the arn operon and loss of aminoarabinose on lipopolysaccharide as the cause of susceptibility to colistin in an atypical clinical isolate of proteus vulgaris

Colistin has become a last-line antibiotic for the treatment of multidrug-resistant bacterial infections; however, resistance to colistin has emerged in recent years. Some bacteria, such as Proteus and Serratia spp., are intrinsically resistant to colistin although the exact mechanism of resistance is unknown. Here we identified the molecular support for intrinsic colistin resistance in Proteus spp. by comparative genomic, transcriptomic and proteomic analyses of colistin-susceptible (CSUR P1868_S) and colistin-resistant (CSUR P1867_R) strains of an atypical Proteus vulgaris. A significant difference in outer membrane glycoside structures in both strains that was corroborated by MALDI-TOF/MS analysis was found, which showed an absence of 4-amino-4-deoxy-l-arabinose (L-Ara4N) in the outer membrane lipid A moiety of the susceptible strain. Comparative genomic analysis with other resistant strains of P. vulgaris available in a local database found a mutation in the arnBCADTEF operon of the susceptible strain. Transcriptomic analysis of genes belonging to the arnBCADTEF operon showed a significant decrease in mRNA expression level of these genes in the susceptible strain, supporting addition of L-Ara4N in the outer membrane lipid A moiety as an explanation for colistin resistance. Insertion of the arnD gene that was suggested to be altered in the susceptible strain by in silico analysis led to a 16-fold increase of colistin MIC in the susceptible strain, confirming its role in colistin resistance in this species. Here we show that constitutive activation of the arn operon and addition of L-Ara4N is the main molecular mechanism of colistin resistance in P. vulgaris.