One Health and Global Health View of Antimicrobial Susceptibility through the "Eye" of Aeromonas: Systematic Review and Meta-Analysis.

Antimicrobial resistance (AMR) is one of the most pressing public health concerns; therefore, it is imperative to advance our understanding of the factors influencing AMR from Global and One Health perspectives. To address this, Aeromonas populations were identified using 16S rRNA gene libraries among human, agriculture, aquaculture, drinking water, surface water, and wastewater samples, supporting its use as indicator bacteria to study AMR. A systematic review and meta-analysis was then performed from Global and One Health perspectives, including data from 221 articles describing 15 891 isolates from 57 countries. The interconnectedness of different environments was evident as minimal differences were identified between sectors among 21 different antimicrobials. However, resistance to critically important antibiotics (aztreonam and cefepime) was significantly higher among wastewater populations compared with clinical isolates. Additionally, isolates from untreated wastewater typically exhibited increased AMR compared with those from treated wastewater. Furthermore, aquaculture was associated with increased AMR to ciprofloxacin and tetracycline compared with wild-caught seafood. Using the World Health Organization AWaRe classifications, countries with lower consumption of "Access" compared to "Watch" drugs from 2000 to 2015 demonstrated higher AMR levels. The current analysis revealed negative correlations between AMR and anthropogenic factors, such as environmental performance indices and socioeconomic standing. Environmental health and sanitation were two of the environmental factors most strongly correlated with AMR. The current analysis highlights the negative impacts of "Watch" drug overconsumption, anthropogenic activity, absence of wastewater infrastructure, and aquaculture on AMR, thus stressing the need for proper infrastructure and global regulations to combat this growing problem.

Inhibitory effects of 405 nm irradiation on Chlamydia trachomatis growth and characterization of the ensuing inflammatory response in HeLa cells.

BACKGROUND: Chlamydia trachomatis is an intracellular bacterium that resides in the conjunctival and reproductive tract mucosae and is responsible for an array of acute and chronic diseases. A percentage of these infections persist even after use of antibiotics, suggesting the need for alternative treatments. Previous studies have demonstrated anti-bacterial effects using different wavelengths of visible light at varying energy densities, though only against extracellular bacteria. We investigated the effects of visible light (405 and 670 nm) irradiation via light emitting diode (LEDs) on chlamydial growth in endocervical epithelial cells, HeLa, during active and penicillin-induced persistent infections. Furthermore, we analyzed the effect of this photo treatment on the ensuing secretion of IL-6 and CCL2, two pro-inflammatory cytokines that have previously been identified as immunopathologic components associated with trichiasis in vivo. RESULTS: C. trachomatis-infected HeLa cells were treated with 405 or 670 nm irradiation at varying energy densities (0 - 20 J/cm2). Bacterial growth was assessed by quantitative real-time PCR analyzing the 16S: GAPDH ratio, while cell-free supernatants were examined for IL-6 and monocyte chemoattractant protein-1 (CCL2) production. Our results demonstrated a significant dose-dependent inhibitory effect on chlamydial growth during both active and persistent infections following 405 nm irradiation. Diminished bacterial load corresponded to lower IL-6 concentrations, but was not related to CCL2 levels. In vitro modeling of a persistent C. trachomatis infection induced by penicillin demonstrated significantly elevated IL-6 levels compared to C. trachomatis infection alone, though 405 nm irradiation had a minimal effect on this production. CONCLUSION: Together these results identify novel inhibitory effects of 405 nm violet light on the bacterial growth of intracellular bacterium C. trachomatis in vitro, which also coincides with diminished levels of the pro-inflammatory cytokine IL-6.

BCG vaccination of guinea pigs modulates Mycobacterium tuberculosis-induced CCL5 (RANTES) production in vitro and in vivo.

CCL5 can attract and activate macrophages and Th1 lymphocytes, which are involved in eliciting a protective immune response against tuberculosis. In this study, the effects of BCG vaccination on CCL5 production in vitro and in vivo in the guinea pig model were examined. Splenocytes, alveolar, and resident peritoneal macrophages obtained from naïve and BCG-vaccinated animals were infected with Mycobacterium tuberculosis in vitro at various time points and analyzed for CCL5 mRNA and protein levels. All three leukocyte populations harvested from BCG-vaccinated guinea pigs and infected with M. tuberculosis produced elevated CCL5 mRNA and protein compared to infected cells from naïve animals. The kinetics of CCL5 production in vivo was evaluated by inducing tuberculous pleurisy in BCG-vaccinated guinea pigs and analyzing CCL5 in pleural effusions at daily intervals. Both CCL5 mRNA and protein levels increased to maximum levels at day 4 post-pleurisy induction. These data suggest that BCG-vaccination enhances CCL5 production in vitro and in vivo. The effect of neutralizing CCL5 with polyclonal anti-CCL5 IgG in vivo during tuberculous pleurisy resulted in a trend toward diminished levels of pro-inflammatory cytokine mRNA, although neutralizing CCL5 in vivo did not appear to alter the intensity of the histopathological response.

Photodynamic inactivation of methicillin-resistant Staphylococcus aureus and Escherichia coli: A metalloporphyrin comparison.

Increasing rates of antibiotic resistance coupled with the lack of novel antibiotics threatens proper clinical treatment and jeopardizes their use in prevention. A photodynamic approach appears to be an innovative treatment option, even for multi-drug resistant strains of bacteria. Three components are utilized in photodynamic inactivation: a photosensitizer, light source, and oxygen. Variations in photosensitizers strongly influence microbial binding and bactericidal activity. In this study, four different cationic metalloporphyrins (Cu2+, Fe2+, Pd2+, Zn2+) were compared to the free-base ligand 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin regarding their electronic properties and generation of reactive oxygen species upon subsequent 405nm violet-blue irradiation. Staphylococcus aureus and Escherichia coli were used as representatives of Gram-positive and -negative, respectively, to assess bactericidal effects by the photodynamic process. Bacterial cultures were pre-incubated with porphyrins and exposed to varying doses of 405nm irradiation (0-30J/cm2). Metalloporphyrins containing Cu2+ and Fe2+ demonstrated minimal effects on viability. Pronounced bactericidal activity was evident with free-base ligand, Zn2+, and Pd2+; though significantly stronger effects were apparent with Pd2+. Photodynamic killing was directly proportional to reactive oxygen species production post-illumination. These data provide new insight into the influence of metal chelation on photosensitizer activity on bactericidal singlet oxygen production. The strong anti-microbial photodynamic action through the use of a portable light-emitting diode over short time intervals (seconds) provides support for its potential use in self-treatment.

Recombinant guinea pig CCL5 (RANTES) differentially modulates cytokine production in alveolar and peritoneal macrophages.

The CC chemokine ligand 5 (CCL5; regulated on activation, normal T expressed and secreted) is known to recruit and activate leukocytes; however, its role in altering the responses of host cells to a subsequent encounter with a microbial pathogen has rarely been studied. Recombinant guinea pig (rgp)CCL5 was prepared, and its influence on peritoneal and alveolar macrophage activation was examined by measuring cytokine and chemokine mRNA expression in cells stimulated with rgpCCL5 alone or exposed to rgpCCL5 prior to lipopolysaccharide (LPS) stimulation. Levels of mRNA for guinea pig tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1beta, CCL2 (monocyte chemoattractant protein-1), and CXC chemokine ligand 8 (IL-8) were analyzed by reverse transcription followed by real-time polymerase chain reaction analysis using SYBR Green. Bioactive TNF-alpha protein concentration was measured using the L929 bioassay. Both macrophage populations displayed significant enhancement of all the genes and TNF-alpha protein levels when stimulated with rgpCCL5, except for CCL2 in alveolar macrophages. When peritoneal or alveolar macrophages were pretreated with rgpCCL5 for 2 h and then exposed to low concentrations of LPS, diminished cytokine and chemokine mRNA levels were apparent at 6 h compared with LPS alone. At the protein level, there was a reduction in TNF-alpha protein at 6 h in the CCL5-pretreated cells compared with LPS alone. These results further support a role for CCL5 in macrophage activation in addition to chemotactic properties and suggest a role in regulating the inflammatory response to LPS in the guinea pig by modulating the production of proinflammatory cytokines by macrophages.

Altered inflammatory responses following transforming growth factor-beta neutralization in experimental guinea pig tuberculous pleurisy.

The predominant extrapulmonary form of tuberculosis, which develops in 10% of diseased individuals, is pleurisy. The immune response mounted against Mycobacterium tuberculosis in the pleural cavity is one that is sufficient for clearing the organism without therapeutic intervention. Thus, examining the role of immune constituents in this context will provide understanding of the vital role they play in controlling tuberculosis. In this study, experimental tuberculous pleurisy was induced in guinea pigs, and anti-TGF-beta was administered intrapleurally to the guinea pigs daily throughout the study (8 days). Neutralizing TGF-beta resulted in a significant reduction in the percentage of lymphocytes and CD8+ cells present in the pleural exudate, decreased proliferative responses of pleural cells to ConA and PPD, and decreased mRNA expression of IFN-gamma and CCL5 in pleural effusion cells. Conversely, the percentage of neutrophils was significantly increased in anti-TGF-beta-treated guinea pigs, along with upregulated mRNA expression of CXCL8. The percentage of macrophages in the pleural exudate, TNF-alpha and IL-12p40 mRNA expression, and the histopathological response were not significantly altered. While TGF-beta is generally thought of as an immunosuppressive cytokine, the results of this study demonstrate its importance in promoting an inflammatory response, and highlight its bipolar nature.

Role of secreted conjunctival mucosal cytokine and chemokine proteins in different stages of trachomatous disease.

BACKGROUND: Chlamydia trachomatis is responsible for trachoma, the primary cause of preventable blindness worldwide. Plans to eradicate trachoma using the World Health Organization's SAFE program (Surgery, Antibiotics, Facial Cleanliness and Environment Improvement) have resulted in recurrence of infection and disease following cessation of treatment in many endemic countries, suggesting the need for a vaccine to control infection and trachomatous disease. Vaccine development requires, in part, knowledge of the mucosal host immune responses in both healthy and trachomatous conjuctivae-an area of research that remains insufficiently studied. METHODOLOGY/PRINCIPAL FINDINGS: We characterized 25 secreted cytokines and chemokines from the conjunctival mucosa of individuals residing in a trachoma endemic region of Nepal using Luminex X100 multiplexing technology. Immunomodulating effects of concurrent C. trachomatis infection were also examined. We found that proinflammatory cytokines IL-1beta (r = 0.259, P = 0.001) and TNFalpha (r = 0.168, P<0.05) were significantly associated with trachomatous disease and concurrent C. trachomatis infection compared with age and sex matched controls from the same region who did not have trachoma. In support of these findings, anti-inflammatory cytokine IL-1 receptor antagonist (IL-1Ra) was negatively associated with chronic scarring trachoma (r = -0.249, P = 0.001). Additional cytokines (Th1, IL-12p40 [r = -0.212, P<0.01], and Th2, IL-4 and IL-13 [r = -0.165 and -0.189, respectively, P<0.05 for both]) were negatively associated with chronic scarring trachoma, suggesting a protective role. Conversely, a pathogenic role for the Th3/Tr1 cytokine IL-10 (r = 0.180, P<0.05) was evident with increased levels for all trachoma grades. New risk factors for chronic scarring trachoma included IL-6 and IL-15 (r = 0.259 and 0.292, respectively, P<0.005 for both) with increased levels for concurrent C. trachomatis infections (r = 0.206, P<0.05, and r = 0.304, P<0.005, respectively). Chemokine protein levels for CCL11 (Eotaxin), CXCL8 (IL-8), CXCL9 (MIG), and CCL2 (MCP-1) were elevated in chronic scarring trachoma compared with age and sex matched controls (P<0.05, for all). CONCLUSIONS/SIGNIFICANCE: Our quantitative detection of previously uncharacterized and partially characterized cytokines, a soluble cytokine receptor, and chemokines for each trachoma grade and associations with C. trachomatis infections provide, to date, the most comprehensive immunologic evaluation of trachoma. These findings highlight novel pathologic and protective factors involved in trachomatous disease, which will aid in designing immunomodulating therapeutics and a vaccine.

Identification of novel single nucleotide polymorphisms in inflammatory genes as risk factors associated with trachomatous trichiasis.

BACKGROUND: Trachoma is the leading preventable cause of global blindness. A balanced Th1/Th2/Th3 immune response is critical for resolving Chlamydia trachomatis infection, the primary cause of trachoma. Despite control programs that include mass antibiotic treatment, reinfection and recurrence of trachoma are common after treatment cessation. Furthermore, a subset of infected individuals develop inflammation and are at greater risk for developing the severe sequela of trachoma known as trachomatous trichiasis (TT). While there are a number of environmental and behavioral risk factors for trachoma, genetic factors that influence inflammation and TT risk remain ill defined. METHODOLOGY/FINDINGS: We identified single nucleotide polymorphisms (SNP) in 36 candidate inflammatory genes and interactions among these SNPs that likely play a role in the overall risk for TT. We conducted a case control study of 538 individuals of Tharu ethnicity residing in an endemic region of Nepal. Trachoma was graded according to World Health Organization guidelines. A linear array was used to genotype 51 biallelic SNPs in the 36 genes. Analyses were performed using logic regression modeling, which controls for multiple comparisons. We present, to our knowledge, the first significant association of TNFA (-308GA), LTA (252A), VCAM1 (-1594TC), and IL9 (T113M) polymorphisms, synergistic SNPs and risk of TT. TT risk decreased 5 times [odds ratio = 0.2 (95% confidence interval 0.11.-0.33), p = 0.001] with the combination of TNFA (-308A), LTA (252A), VCAM1 (-1594C), SCYA 11 (23T) minor allele, and the combination of TNFA (-308A), IL9 (113M), IL1B (5'UTR-T), and VCAM1 (-1594C). However, TT risk increased 13.5 times [odds ratio = 13.5 (95% confidence interval 3.3-22), p = 0.001] with the combination of TNFA (-308G), VDR (intron G), IL4R (50V), and ICAM1 (56M) minor allele. CONCLUSIONS: Evaluating genetic risk factors for trachoma will advance our understanding of disease pathogenesis, and should be considered in the context of designing global control programs.