Actinobacillus pleuropneumoniae, surface proteins and virulence: a review.

Actinobacillus pleuropneumoniae (App) is a globally distributed Gram-negative bacterium that produces porcine pleuropneumonia. This highly contagious disease produces high morbidity and mortality in the swine industry. However, no effective vaccine exists to prevent it. The infection caused by App provokes characteristic lesions, such as edema, inflammation, hemorrhage, and necrosis, that involve different virulence factors. The colonization and invasion of host surfaces involved structures and proteins such as outer membrane vesicles (OMVs), pili, flagella, adhesins, outer membrane proteins (OMPs), also participates proteases, autotransporters, and lipoproteins. The recent findings on surface structures and proteins described in this review highlight them as potential immunogens for vaccine development.

Bougainvillea glabra Choisy (Nyctinaginacea): review of phytochemistry and antimicrobial potential.

The Bougainvillea glabra or bougainvillea is a climbing plant native from South America belonging to the Nyctaginaceae family. The bougainvillea is recognized worldwide for its horticultural importance, due to the color of its bracts, commonly known as "flowers," made up of bracts, which are the striking parts, and the true flowers, which are white and small. Bougainvillea is widely known in traditional medicine to treat respiratory diseases such as cough, asthma, and bronchitis, gastrointestinal diseases, also for its antibacterial and insecticidal capacity. The antimicrobial potential of the involucre of this plant has not been studied, despite research showing a high phytochemical presence of secondary metabolites such as alkanes, phenols, terpenes, and betalains. This review compiles information about the traditional uses of B. glabra, its botanical description, ecological relevance, phytochemistry, antimicrobial and antibiofilm activity, such as the toxicology of bracts and flowers.

An overview of carbapenem-resistant organisms from food-producing animals, seafood, aquaculture, companion animals, and wildlife.

Carbapenem resistance (CR) is a major global health concern. CR is a growing challenge in clinical settings due to its rapid dissemination and low treatment options. The characterization of its molecular mechanisms and epidemiology are highly studied. Nevertheless, little is known about the spread of CR in food-producing animals, seafood, aquaculture, wildlife, their environment, or the health risks associated with CR in humans. In this review, we discuss the detection of carbapenem-resistant organisms and their mechanisms of action in pigs, cattle, poultry, seafood products, companion animals, and wildlife. We also pointed out the One Health approach as a strategy to attempt the emergency and dispersion of carbapenem-resistance in this sector and to determine the role of carbapenem-producing bacteria in animals among human public health risk. A higher occurrence of carbapenem enzymes in poultry and swine has been previously reported. Studies related to poultry have highlighted P. mirabilis, E. coli, and K. pneumoniae as NDM-5- and NDM-1-producing bacteria, which lead to carbapenem resistance. OXA-181, IMP-27, and VIM-1 have also been detected in pigs. Carbapenem resistance is rare in cattle. However, OXA- and NDM-producing bacteria, mainly E. coli and A. baumannii, are cattle's leading causes of carbapenem resistance. A high prevalence of carbapenem enzymes has been reported in wildlife and companion animals, suggesting their role in the cross-species transmission of carbapenem-resistant genes. Antibiotic-resistant organisms in aquatic environments should be considered because they may act as reservoirs for carbapenem-resistant genes. It is urgent to implement the One Health approach worldwide to make an effort to contain the dissemination of carbapenem resistance.

Detection of microbial biofilms inside the lumen of ureteral stents: two case reports.

BACKGROUND: We report large biofilm structures that covered almost the entirety of the lumen and surface of double-J stents in two postrenal transplant patients, with no development of urinary tract infection. Biofilm bacteria of one patient were integrated by coccus in a net structure, whereas overlapping cells of bacilli were present in the other patient. To the best of our knowledge, this is the first time that high-quality images of the architecture of noncrystalline biofilms have been found inside double-J stents from long-term stenting in renal transplant recipients. CASE PRESENTATION: Two renal transplant recipients, a 34-year-old male and a 39-year-old female of Mexican-Mestizo origin, who underwent a first renal transplant and lost it due to allograft failure, had a second transplant. Two months after the surgical procedure, double-J stents were removed and analyzed using scanning electron microscopy (SEM). None of the patients had an antecedent of UTI, and none developed UTI after urinary device removal. There were no reports of injuries, encrustation, or discomfort caused by these devices. CONCLUSION: The bacterial biofilm inside the J stent from long-term stenting in renal transplant recipients was mainly concentrated on unique bacteria. Biofilm structures from the outside and inside of stents do not have crystalline phases. Internal biofilms may represent a high number of bacteria in the double-J stent, in the absence of crystals.

Serpin-A3 is Associated with Persistent Albuminuria in Adolescents with Secondary Podocytopathy, in a Region with High Prevalence of Chronic Kidney Disease of Unknown Origin

Abstract Background: The state of Aguascalientes, Mexico, has been recognized as a chronic kidney disease hotspot. Screening studies have revealed a high prevalence of persistent albuminuria (pA), histologically characterized by glomerulomegaly, and incomplete podocyte fusion, probably associated with oligonephrony. To date, urinary biomarkers have not been explored in this population. Objective: The aim of the study was to identify the presence of potential biomarkers of early renal injury in patients with pA (pACR) and that correspond with the characteristic nephropathy profile that prevails in this entity. Methods: This is a cross-sectional, analytical, and comparative study. Four groups were recruited: adolescents aged 10-17 years with pACR, isolated albuminuria (iACR), no albuminuria (negative control), and adults with biopsy-confirmed glomerulopathy (positive control). Urinary excretion of SerpinA3, heat-shock protein-72 (HSP-72), podocalyxin (PCX), and nephrin was evaluated in urine samples. SerpinA3 and HSP-72 were analyzed by Western blot, and PCX and nephrin were quantified by enzyme-linked immunosorbent assay. Results: The mean GFR in the pACR group was 113.4 mL/min/1.73m2 and differed significantly only from that of the positive control group (65.1 mL/min/1.73m2). The mean albuminuria value in the pACR group was 48.9 mg/g. SerpinA3 concentration differed between groups (0.08 vs. 0.25 ng/mL, p < 0.001): it was significantly higher in the pACR group compared to the negative controls (p = 0.037). Conclusion: SerpinA3 was significantly associated with pA and could become a biomarker of early kidney injury. Further investigations are required to determine whether SerpinA3 precedes the development of albuminuria and its pathogenic role.

Psidium guajava L.: From byproduct and use in traditional Mexican medicine to antimicrobial agent.

Mexico is one of the largest guava producers in the world, so it has access to a huge amount of waste and byproducts obtained after the industrial processing of the fruit. This review discusses the potential recovery of this residue for its application as an antimicrobial agent, considering the phytochemical composition, the bioactivity reported in-vivo and in-vitro, and the toxicology of the plant. Nowadays there is a growing demand for more natural and safer products, so the use of guava extracts is an interesting initiative, especially due to its availability in the country, its wide variety of traditional uses, and its phytochemical profile. This review highlights the importance and potential antimicrobial use of this plant in today's world.

Serpin-A3 is Associated with Persistent Albuminuria in Adolescents with Secondary Podocytopathy, in a Region with High Prevalence of Chronic Kidney Disease of Unknown Origin.

Background: The state of Aguascalientes, Mexico, has been recognized as a chronic kidney disease hotspot. Screening studies have revealed a high prevalence of persistent albuminuria (pA), histologically characterized by glomerulomegaly, and incomplete podocyte fusion, probably associated with oligonephrony. To date, urinary biomarkers have not been explored in this population. Objective: The aim of the study was to identify the presence of potential biomarkers of early renal injury in patients with pA (pACR) and that correspond with the characteristic nephropathy profile that prevails in this entity. Methods: This is a cross-sectional, analytical, and comparative study. Four groups were recruited: adolescents aged 10-17 years with pACR, isolated albuminuria (iACR), no albuminuria (negative control), and adults with biopsy-confirmed glomerulopathy (positive control). Urinary excretion of SerpinA3, heat-shock protein-72 (HSP-72), podocalyxin (PCX), and nephrin was evaluated in urine samples. SerpinA3 and HSP-72 were analyzed by Western blot, and PCX and nephrin were quantified by enzyme-linked immunosorbent assay. Results: The mean GFR in the pACR group was 113.4 mL/min/1.73m2 and differed significantly only from that of the positive control group (65.1 mL/min/1.73m2). The mean albuminuria value in the pACR group was 48.9 mg/g. SerpinA3 concentration differed between groups (0.08 vs. 0.25 ng/mL, p < 0.001): it was significantly higher in the pACR group compared to the negative controls (p = 0.037). Conclusion: SerpinA3 was significantly associated with pA and could become a biomarker of early kidney injury. Further investigations are required to determine whether SerpinA3 precedes the development of albuminuria and its pathogenic role.

Actinobacillus pleuropneumoniae Surviving on Environmental Multi-Species Biofilms in Swine Farms.

Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumonia, an important respiratory disease for the pig industry. A. pleuropneumoniae has traditionally been considered an obligate pig pathogen. However, its presence in the environment is starting to be known. Here, we report the A. pleuropneumoniae surviving in biofilms in samples of drinking water of swine farms from Mexico. Fourteen farms were studied. Twenty drinking water samples were positive to A. pleuropneumoniae distributed on three different farms. The bacteria in the drinking water samples showed the ability to form biofilms in vitro. Likewise, A. pleuropneumoniae biofilm formation in situ was observed on farm drinkers, where the biofilm formation was in the presence of other bacteria such as Escherichia coli, Stenotrophomonas maltophilia, and Acinetobacter schindleri. Our data suggest that A. pleuropneumoniae can inhabit aquatic environments using multi-species biofilms as a strategy to survive outside of their host.

Expression of enamel proteins in human dental pulp stem cells by the effect of extracellular matrix / Expresión de proteínas de esmalte en células madre de pulpa dental humana por el efecto de matriz extracelular

SUMMARY: Mesenchymal stem cells are present in adult tissues such as the human dental pulp. They are pluripotent and can differentiate into various specialized cell types in vitro through appropriate stimuli. Ameloblasts produce human tooth enamel only during embryonic development before tooth eruption, so endogenous regeneration is not possible. Various efforts have been aimed at generating natural or artificial substitutes for dental enamel with properties similar to the specific components of said tissue. The purpose of this study was to induce human dental pulp stem cells to produce enamel proteins using extracellular matrix derived from the rat tail tendon and pigskin. Primary cultures of human dental pulp stem cells were established and characterized by RT-PCR and immunofluorescence, using mesenchymal cell markers such as CD14, CD40, CD44, CD105, and STRO-1. The cells were then incubated with the extracellular matrix for fourteen days and labeled with specific antibodies to detect the expression of dental enamel proteins such as amelogenin, ameloblastin, enamelisin, tuftelin, and parvalbumin, characteristics of the phenotype of ameloblasts. This work demonstrated a positive effect of the extracellular matrix to induce the expression of enamel proteins in the stem cells of the human dental pulp.

RESUMEN: Las células madre mesenquimales están presentes en los tejidos adultos como la pulpa dental humana. Son pluripotentes y pueden diferenciarse en varios tipos de células especializadas in vitro a través de estímulos adecuados. Los ameloblastos producen esmalte dental humano sólo durante el desarrollo embrionario antes de la erupción dental, por lo que no es posible su regeneración endógena. Varios esfuerzos se han orientado a generar sustitutos naturales o artificiales de esmalte dental con propiedades similares a los componentes específicos de este tejido. El propósito de este estudio fue inducir células madre de pulpa dental humana para producir proteínas del esmalte dental a través del estímulo de matriz extracelular derivada del tendón de la cola de rata y piel de cerdo. Se establecieron cultivos primarios de células madre de pulpa dental humana y se caracterizaron por RT-PCR e inmunofluorescencia utilizando marcadores de células mesenquimales como CD14, CD40, CD44, CD105 y STRO-1. Posteriormente, las células se incubaron con matriz extracelular durante un período de catorce días y se marcaron con anticuerpos específicos para detectar la expresión de proteínas de esmalte dental como amelogenina, ameloblastina, enamelisina, tuftelina y parvalbúmina, las cuales son características del fenotipo de ameloblastos. Este trabajo demostró el efecto positivo que tiene el empleo de la matriz extracelular para inducir la expresión de proteínas de esmalte en las células pluripotenciales de la pulpa dental humana.

Actinobacillus pleuropneumoniae Interaction With Swine Endothelial Cells.

Actinobacillus pleuropneumonia is a swine (host) specific respiratory pathogen and the etiological agent of swine pleuropneumonia which affects pigs of all ages, many being asymptomatic carriers. This pathogen has high morbidity and mortality rates which generates large economic losses for the pig industry. Actinobacillus pleuropneumoniae is a widely studied bacterium, however its pathogenesis is not yet fully understood. The prevalence of the 18 serotypes of A. pleuropneumoniae varies by geographic region, in North American area, more specifically in Mexico, serotypes 1, 3, 5b, and 7 show higher prevalence. Actinobacillus pleuropneumoniae is described as a strict extracellular pathogen with tropism for lower respiratory tract. However, this study depicts the ability of these serotypes to adhere to non-phagocytic cells, using an endothelial cell model, as well as their ability to internalize them, proposing it could be considered as an intracellular pathogen.

Incorporation of Actinobacillus pleuropneumoniae in Preformed Biofilms by Escherichia coli Isolated From Drinking Water of Swine Farms.

Actinobacillus pleuropneumoniae, the etiological agent of porcine pleuropneumonia, represents one of the most important health problems in the swine industry worldwide and it is included in the porcine respiratory disease complex. One of the bacterial survival strategies is biofilm formation, which are bacterial communities embedded in an extracellular matrix that could be attached to a living or an inert surface. Until recently, A. pleuropneumoniae was considered to be an obligate pathogen. However, recent studies have shown that A. pleuropneumoniae is present in farm drinking water. In this study, the drinking water microbial communities of Aguascalientes (Mexico) swine farms were analyzed, where the most frequent isolated bacterium was Escherichia coli. Biofilm formation was tested in vitro; producing E. coli biofilms under optimal growth conditions; subsequently, A. pleuropneumoniae serotype 1 (strains 4074 and 719) was incorporated to these biofilms. Interaction between both bacteria was evidenced, producing an increase in biofilm formation. Extracellular matrix composition of two-species biofilms was also characterized using fluorescent markers and enzyme treatments. In conclusion, results confirm that A. pleuropneumoniae is capable of integrates into biofilms formed by environmental bacteria, indicative of a possible survival strategy in the environment and a mechanism for disease dispersion.

An evaluation of multidrug-resistant Escherichia coli isolates in urinary tract infections from Aguascalientes, Mexico: cross-sectional study.

BACKGROUND: Uropathogenic Escherichia coli (UPEC) are one of the main bacteria causing urinary tract infections (UTIs). The rates of UPEC with high resistance towards antibiotics and multidrug-resistant bacteria have increased dramatically in recent years and could difficult the treatment. METHODS: The aim of the study was to determine multidrug-resistant bacteria, antibiotic resistance profile, virulence traits, and genetic background of 110 E. coli isolated from community (79 isolates) and hospital-acquired (31 isolates) urinary tract infections. The plasmid-mediated quinolone resistance genes presence was also investigated. A subset of 18 isolates with a quinolone-resistance phenotype was examined for common virulence genes encoded in diarrheagenic and extra-intestinal pathogenic E. coli by a specific E. coli microarray. RESULTS: Female children were the group most affected by UTIs, which were mainly community-acquired. Resistance to trimethoprim-sulfamethoxazole, ampicillin, and ampicillin-sulbactam was most prevalent. A frequent occurrence of resistance toward ciprofloxacin (47.3%), levofloxacin (43.6%) and cephalosporins (27.6%) was observed. In addition, 63% of the strains were multidrug-resistant (MDR). Almost all the fluoroquinolone (FQ)-resistant strains showed MDR-phenotype. Isolates from male patients were associated to FQ-resistant and MDR-phenotype. Moreover, hospital-acquired infections were correlated to third generation cephalosporin and nitrofurantoin resistance and the presence of kpsMTII gene. Overall, fimH (71.8%) and fyuA (68.2%), had the highest prevalence as virulence genes among isolates. However, the profile of virulence genes displayed a great diversity, which included the presence of genes related to diarrheagenic E. coli. Out of 110 isolates, 25 isolates (22.7%) were positive to qnrA, 23 (20.9%) to qnrB, 7 (6.4%) to qnrS1, 7 (6.4%) to aac(6')lb-cr, 5 (4.5%) to qnrD, and 1 (0.9%) to qnrC genes. A total of 12.7% of the isolates harbored blaCTX-M genes, with blaCTX-M-15 being the most prevalent. CONCLUSIONS: Urinary tract infection due to E. coli may be difficult to treat empirically due to high resistance to commonly used antibiotics. Continuous surveillance of multidrug resistant organisms and patterns of drug resistance are needed in order to prevent treatment failure and reduce selective pressure. These findings may help choosing more suitable treatments of UTI patients in this region of Mexico.

Auxotrophic Actinobacillus pleurpneumoniae grows in multispecies biofilms without the need for nicotinamide-adenine dinucleotide (NAD) supplementation.

BACKGROUND: Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumonia, which causes important worldwide economic losses in the swine industry. Several respiratory tract infections are associated with biofilm formation, and A. pleuropneumoniae has the ability to form biofilms in vitro. Biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that are attached to an abiotic or biotic surface. Virtually all bacteria can grow as a biofilm, and multi-species biofilms are the most common form of microbial growth in nature. The goal of this study was to determine the ability of A. pleuropneumoniae to form multi-species biofilms with other bacteria frequently founded in pig farms, in the absence of pyridine compounds (nicotinamide mononucleotide [NMN], nicotinamide riboside [NR] or nicotinamide adenine dinucleotide [NAD]) that are essential for the growth of A. pleuropneumoniae. RESULTS: For the biofilm assay, strain 719, a field isolate of A. pleuropneumoniae serovar 1, was mixed with swine isolates of Streptococcus suis, Bordetella bronchiseptica, Pasteurella multocida, Staphylococcus aureus or Escherichia coli, and deposited in 96-well microtiter plates. Based on the CFU results, A. pleuropneumoniae was able to grow with every species tested in the absence of pyridine compounds in the culture media. Interestingly, A. pleuropneumoniae was also able to form strong biofilms when mixed with S. suis, B. bronchiseptica or S. aureus. In the presence of E. coli, A. pleuropneumoniae only formed a weak biofilm. The live and dead populations, and the matrix composition of multi-species biofilms were also characterized using fluorescent markers and enzyme treatments. The results indicated that poly-N-acetyl-glucosamine remains the primary component responsible for the biofilm structure. CONCLUSIONS: In conclusion, A. pleuropneumoniae apparently is able to satisfy the requirement of pyridine compounds through of other swine pathogens by cross-feeding, which enables A. pleuropneumoniae to grow and form multi-species biofilms.

Presence of multi-drug resistant pathogenic Escherichia coli in the San Pedro River located in the State of Aguascalientes, Mexico.

Contamination of surface waters in developing countries is a great concern. Treated and untreated wastewaters have been discharged into rivers and streams, leading to possible waterborne infection outbreaks and may represent a significant dissemination mechanism of antibiotic resistance genes. In this study, the water quality of San Pedro River, the main river and pluvial collector of the Aguascalientes State, Mexico was assessed. Thirty sample locations were tested throughout the River. The main physicochemical parameters of water were evaluated. Results showed high levels of fecal pollution as well as inorganic and organic matter abundant enough to support the heterotrophic growth of microorganisms. These results indicate poor water quality in samples from different locations. One hundred and fifty Escherichia coli were collected and screened by PCR for several virulence genes. Isolates were classified as either pathogenic (n = 91) or commensal (n = 59). The disc diffusion method was used to determine antimicrobial susceptibility to 13 antibiotics. Fifty-two percent of the isolates were resistant to at least one antimicrobial agent and 30.6% were multi-resistant. Eighteen E. coli strains were quinolone resistant of which 16 were multi-resistant. Plasmid-mediated quinolone resistance (PMQR) genes were detected in 12 isolates. Mutations at the Ser-83→Leu and/or Asp-87→Asn in the gyrA gene were detected as well as mutations at the Ser-80→Ile in parC. An E. coli microarray (Maxivirulence V 3.1) was used to characterize the virulence and antimicrobial resistance genes profiles of the fluoroquinolone-resistant isolates. Antimicrobial resistance genes such as bla TEM, sulI, sulII, dhfrIX, aph3 (strA), and tet (B) as well as integrons were found in fluoroquinolone (FQ) resistance E. coli strains. The presence of potential pathogenic E. coli and antibiotic resistance in San Pedro River such as FQ resistant E. coli could pose a potential threat to human and animal health.

Detection of Actinobacillus pleuropneumoniae in drinking water from pig farms.

Actinobacillus pleuropneumoniae is the aetiological agent of porcine pleuropneumonia and is normally transmitted by aerosols and direct contact between animals. A. pleuropneumoniae has traditionally been considered an obligate pathogen of pigs and its presence in the environment has yet to be investigated. Here, the presence of A. pleuropneumoniae was detected in drinking water of pig farms in Mexico using a PCR specific for the RTX toxin gene, apxIV. The presence of A. pleuropneumoniae in farm drinking water was confirmed by indirect immunofluorescence using an A. pleuropneumoniae-specific polyclonal antibody and by fluorescent in situ hybridization. Viable bacteria from the farm drinking water were detected using the Live/Dead BacLight stain. Additionally, viable A. pleuropneumoniae was selected and isolated using the cAMP test and the identity of the isolated bacteria were confirmed by Gram staining, a specific polyclonal antibody and an A. pleuropneumoniae-specific PCR. Furthermore, biofilms were observed by scanning electron microscopy in A. pleuropneumoniae-positive samples. In conclusion, our data suggest that viable A. pleuropneumoniae is present in the drinking water of swine farms and may use biofilm as a strategy to survive in the environment.

Pathogenic and opportunistic gram-negative bacteria in soil, leachate and air in San Nicolás landfill at Aguascalientes, Mexico.

The occurrence of Gram-negative pathogenic and opportunistic species, was studied for two years on air. soil and leachate from the San Nicolás Landfill. Aguascalientes, Mexico. For soil and leachate four samplings were done, two during the dry season and two during the rainy season. For soil there were 15 sampling points, the leachate samples were taken on the leachate tank. For air, twelve sampling were done in three points of the landfill. Twenty pathogenic and/or opportunistic bacteria were identified from air, twenty from soil and eleven from leachate. Most of them were enteric; however respiratory tract pathogenic bacteria were also identified. Pasteurella haemolytica were isolated in all air samples. Nine species were found in the a half of the soil samples. The most frequent species in leachate were Acinetobacter baumanii, Bordetella sp, Brucella sp. and Escherichia coli var II. The occurrence of pathogenic and opportunistic species points out to the nosocomial and domestic clinical wastes discharged in the landfill as a potential risk for public and occupational health.