Use of RNA-seq to identify genes encoding cytokines and chemokines activated following uptake and processing a candidate peptide vaccine developed against Mycobacterium avium subsp. paratuberculosis.

Analysis of the primary and recall responses to a membrane molecule (MMP), encoded by MAP2121c demonstrated that tri-directional signaling between the antigen-presenting cell (APC), CD4 and CD8 is essential for eliciting a CD8 cytotoxic T cell (CTL) response against Mycobacterium avium subsp. paratuberculosis. As reported here, RNA-sequencing was used to initiate the characterization of the signaling pathways involved in eliciting the development of CD8 CTL, starting with the characterization of the activation status of genes in monocyte-derived macrophages (MoMΦ) following uptake and processing MMP for the presentation of antigenic epitopes to CD4 and CD8 T cells. Activation status was compared with the uptake and processing of LPS, a nonspecific stimulator of macrophages. 1609 genes were identified that were upregulated, and 1277 were downregulated three hours after uptake and processing MMP. No significant difference was observed in the cytokine genes selected for analysis of the signaling that must occur between APC, CD4, and CD8 for the development of CTL. The initial observations indicate screening of the transcriptome should include genes involved in signaling between APC and CD4, and CD8 regardless of their activation status. Four genes of interest in this study, IL12A, IL12B, IL15, and IL23A, were not significantly different from control values. The initial studies also indicate MoMΦ can be included with dendritic cells and monocyte-derived dendritic cells for further analysis of the tri-directional signaling required for the development of CTL.

A análise das respostas primárias e de recall a uma molécula de membrana (MMP), codificada por MAP2121c demonstrou que a sinalização tridirecional entre a célula apresentadora de antígeno (APC), CD4 e CD8 é essencial para provocar uma resposta de células T citotóxicas CD8 (CTL) contra Mycobacterium avium subsp. paratuberculose. Conforme relatado aqui, o sequenciamento de RNA foi usado para iniciar a caracterização das vias de sinalização envolvidas na indução do desenvolvimento de CTL CD8, começando com a caracterização do status de ativação de genes em macrófagos derivados de monócitos (MoMΦ) após captação e processamento de MMP para a apresentação de epítopos antigênicos às células T CD4 e CD8. O status de ativação foi comparado com a captação e processamento de LPS, um estimulador inespecífico de macrófagos. Foram identificados 1.609 genes que foram regulados positivamente e 1.277 foram regulados negativamente três horas após a captação e processamento de MMP. Nenhuma diferença significativa foi observada nos genes de citocinas selecionados para análise da sinalização que deve ocorrer entre APC, CD4 e CD8 para o desenvolvimento de CTL. As observações iniciais indicam que o rastreio do transcriptoma deve incluir genes envolvidos na sinalização entre APC e CD4 e CD8, independentemente do seu estado de activação. Quatro genes de interesse neste estudo, IL12A, IL12B, IL15 e IL23A, não foram significativamente diferentes dos valores de controle. Os estudos iniciais também indicam que o MoMΦ pode ser incluído com células dendríticas e células dendríticas derivadas de monócitos para análise adicional da sinalização tridirecional necessária para o desenvolvimento de CTL.

Assessment of nationally recommended antibiotics for treatment of UTI in U.S.-Mexico border emergency departments.

BACKGROUND: Urinary tract infections (UTIs) seen in the emergency department are commonly treated as an outpatient with oral antibiotics. Given that antibiotics are available for over-the-counter purchase in Mexico, there is speculation that potential misuse and overuse of antibiotics in United States-Mexico border areas could lead to antibiotic resistance patterns that would render some empiric treatments for UTIs less effective. The purpose of this study was to examine the effectiveness of Infectious Disease Society of America (IDSA) guideline-recommended antibiotics for treatment of outpatient UTI diagnosed in the emergency department. Data were collected from a county hospital on the U.S.-Mexico border with a metropolitan area of over 2 million people. Secondary analysis included frequency of urine culture isolated, resistance rates of urine pathogens, and prescriber habits. METHODS: This study was a retrospective chart review of adult patients diagnosed and treated for UTI from August 1, 2019, to February 29, 2020. Culture results of included patients were analyzed against in vitro-tested antibiotics. Bacterial isolate frequency, resistance rates, and prescribing habits were collected. RESULTS: A total of 985 patient charts were reviewed, of which 520 patients met inclusion criteria for analysis of prescribing habits. Of these, 329 positive bacterial culture growths were included in the analysis of antibiotic resistance rates. Oral antibiotics with comparatively lower resistance rates were amoxicillin/clavulanate, cefdinir, cefuroxime, and nitrofurantoin. Oral antibiotics with notably high resistance rates included trimethoprim-sulfamethoxazole (TMP-SMX), tetracycline, ciprofloxacin, levofloxacin, and cephalexin. Nitrofurantoin was prescribed most frequently for outpatient treatment of UTI/cystitis (41.6%) while cephalexin was the most commonly prescribed antibiotic for outpatient treatment of pyelonephritis (50%). CONCLUSION: Our findings suggest that, while part of standard IDSA guidelines, fluoroquinolones and TMP-SMX are not ideal empiric antibiotics for treatment of outpatient UTI in the U.S.-Mexico border region studied due to high resistance rates. Although not listed as first line agents per current IDSA recommendations, 2nd and 3rd generation cephalosporins, and amoxicillin/clavulanate would be acceptable options given resistance patterns demonstrated in accordance with IDSA allowance for tailoring selection to local resistance. Nitrofurantoin appears to be consistent with recommendations and demonstrates a favorable resistance profile for treatment of outpatient UTI within this region.

Incidence and seasonality of respiratory viruses among medically attended children with acute respiratory infections in an Ecuador birth cohort, 2011-2014.

BACKGROUND: Ecuador annually has handwashing and respiratory hygiene campaigns and seasonal influenza vaccination to prevent respiratory virus illnesses but has yet to quantify disease burden and determine epidemic timing. METHODS: To identify respiratory virus burden and assess months with epidemic activity, we followed a birth cohort in northwest Ecuador during 2011-2014. Mothers brought children to the study clinic for routine checkups at ages 1, 2, 3, 5, and 8 years or if children experienced any acute respiratory illness symptoms (e.g., cough, fever, or difficulty breathing); clinical care was provided free of charge. Those with medically attended acute respiratory infections (MAARIs) were tested for common respiratory viruses via real-time reverse-transcription polymerase chain reaction (rRT-PCR). RESULTS: In 2011, 2376 children aged 1-4 years (median 35 months) were enrolled in the respiratory cohort and monitored for 7017.5 child-years (cy). The incidence of respiratory syncytial virus (RSV) was 23.9 (95% CI 17.3-30.5), influenza 10.6 (2.4-18.8), adenoviruses 6.7 (4.6-28.0), parainfluenzas 5.0 (2.3-10.5), and rhinoviruses, bocaviruses, human metapneumoviruses, seasonal coronaviruses, and enteroviruses <3/100 cy among children aged 12-23 months and declined with age. Most (75%) influenza detections occurred April-September. CONCLUSION: Cohort children frequently had MAARIs, and while the incidence decreased rapidly among older children, more than one in five children aged 12-23 months tested positive for RSV, and one in 10 tested positive for influenza. Our findings suggest this substantial burden of influenza occurred more commonly during the winter Southern Hemisphere influenza season.

Effect of the deletion of lprG and p55 genes in the K10 strain of Mycobacterium avium subspecies paratuberculosis.

The lprG-p55 operon of Mycobacterium tuberculosis, M. bovis and M. avium strain D4ER has been identified as a virulence factor involved in the transport of toxic compounds. LprG is a lipoprotein that modulates the host immune response against mycobacteria, whereas P55 is an efflux pump that provides resistance to several drugs. In the present study we search for, and characterize, lprg and p55, putative virulence genes in Mycobacterium avium subsp. paratuberculosis (MAP) to generate a live-attenuated strain of MAP that may be useful in the future as live-attenuated vaccine. For this purpose, we generated and evaluated two mutants of MAP strain K10: one mutant lacking the lprG gene (ΔlprG) and the other lacking both genes lprG and p55 (ΔlprG-p55). None of the mutant strains showed altered susceptibility to first-line and second-line antituberculosis drugs or ethidium bromide, only the double mutant had two-fold increase in clarithromycin susceptibility compared with the wild-type strain. The deletion of lprG and of lprG-p55 reduced the replication of MAP in bovine macrophages; however, only the mutant in lprG-p55 grew faster in liquid media and showed reduced viability in macrophages and in a mouse model. Considering that the deletion of both genes lprG-p55, but not that of lprG alone, showed a reduced replication in vivo, we can speculate that p55 contributes to the survival of MAP in this animal model.

'Lipo-tourism' gone wrong: blood transfusion-transmitted cytomegalovirus disease.

Medical tourism is the pursuit of more affordable surgeries; however, this comes at the risk of suboptimal standards and potential for life-threatening complications. In this case, we describe the diagnostic challenge of cytomegalovirus (CMV) pneumonia in a 40-year-old woman who experienced wound dehiscence and subsequent blood transfusion-transmitted CMV as complications of liposuction in the Dominican Republic. We explore the role of histopathology in the diagnosis of disseminated CMV, discuss the underlying aetiology of CMV pneumonia in this patient and weigh the risks and benefits of initiating antiviral therapy in an immunocompetent patient with CMV disease.

Extensive hybridization and past introgression between divergent lineages in a quasi-clonal hermaphroditic fish: Ramifications for species concepts and taxonomy.

Extreme inbreeding is expected to reduce the incidence of hybridization, serving as a prezygotic barrier. Mangrove rivulus is a small killifish that reproduces predominantly by self-fertilization, producing highly homozygous lines throughout its geographic range. The Bahamas and Caribbean are inhabited by two highly diverged phylogeographic lineages of mangrove rivulus, Kryptolebias marmoratus and a 'Central clade' closely related to K. hermaphroditus from Brazil. The two lineages are largely allopatric, but recently were found in syntopy on San Salvador, Bahamas, where a single hybrid was reported. To better characterize the degree of hybridization and the possibility of secondary introgression, here we conducted a detailed genetic analysis of the contact zone on San Salvador. Two mixed populations were identified, one of which contained sexually mature hybrids. The distribution of heterozygosity at diagnostic microsatellite loci in hybrids showed that one of these hybrids was an immediate offspring from the K. marmoratus x Central clade cross, whereas the remaining five hybrids were products of reproduction by self-fertilization for 1-3 generations following the initial cross. Two hybrids had mitochondrial haplotypes of K. marmoratus and the remaining four hybrids had a haplotype of the Central clade, indicating that crosses go in both directions. In hybrids, alleles of parental lineages were represented in equal proportions suggesting lack of recent backcrossing to either of the parental lineages. However, sympatric populations of two lineages were less diverged than allopatric populations, consistent with introgression. Results are discussed in terms of applicability of the biological species concept for isogenic, effectively clonal, organisms.

Natural hybridization between divergent lineages in a selfing hermaphroditic fish.

By definition, mating between individuals is infrequent in highly selfing organisms, and so too, therefore, hybridization should be rare between genetically divergent lineages in predominantly self-fertilizing species. Notwithstanding these expectations, here we report a remarkable case of natural hybridization between highly diverged phylogeographic lineages of the mangrove rivulus, a small killifish that reproduces predominantly by self-fertilization and typically is found as highly homozygous lines in most parts of its extensive geographical range. Two distinctive genetic lineages (Kryptolebias marmoratus and a 'Central clade' closely related to K. hermaphroditus) previously were not known in sympatry, but were found by us to co-occur on San Salvador, Bahamas. Genetic analyses of a mitochondrial and multiple nuclear markers determined the direction of a cross producing a hybrid fish. Furthermore, we show that this hybrid individual was viable, as it successfully reproduced by self-fertilization for two generations. Additional sampling of this population will be necessary to determine if backcrossing of hybrids to the parental lineages occurs in nature and to analyse whether such backcross progeny are viable. Application of the biological species concept (BSC) is traditionally difficult in clonally reproducing organisms. Our results show that although mangrove rivulus fish are mostly highly selfing in nature (resulting in isogenic, effectively clonal and homozygous progeny), classification within this taxonomic complex need not be incompatible with the BSC.

Transfected Babesia bovis Expressing a Tick GST as a Live Vector Vaccine.

The Rhipicephalus microplus tick is a notorious blood-feeding ectoparasite of livestock, especially cattle, responsible for massive losses in animal production. It is the main vector for transmission of pathogenic bacteria and parasites, including Babesia bovis, an intraerythrocytic apicomplexan protozoan parasite responsible for bovine Babesiosis. This study describes the development and testing of a live B. bovis vaccine expressing the protective tick antigen glutathione-S-transferase from Haemaphysalis longicornis (HlGST). The B. bovis S74-T3B parasites were electroporated with a plasmid containing the bidirectional Ef-1α (elongation factor 1 alpha) promoter of B. bovis controlling expression of two independent genes, the selectable marker GFP-BSD (green fluorescent protein-blasticidin deaminase), and HlGST fused to the MSA-1 (merozoite surface antigen 1) signal peptide from B. bovis. Electroporation followed by blasticidin selection resulted in the emergence of a mixed B. bovis transfected line (termed HlGST) in in vitro cultures, containing parasites with distinct patterns of insertion of both exogenous genes, either in or outside the Ef-1α locus. A B. bovis clonal line termed HlGST-Cln expressing intracellular GFP and HlGST in the surface of merozoites was then derived from the mixed parasite line HlGST using a fluorescent activated cell sorter. Two independent calf immunization trials were performed via intravenous inoculation of the HlGST-Cln and a previously described control consisting of an irrelevant transfected clonal line of B. bovis designated GFP-Cln. The control GFP-Cln line contains a copy of the GFP-BSD gene inserted into the Ef-1α locus of B. bovis in an identical fashion as the HIGST-Cln parasites. All animals inoculated with the HlGST-Cln and GFP-Cln transfected parasites developed mild babesiosis. Tick egg fertility and fully engorged female tick weight was reduced significantly in R. microplus feeding on HlGST-Cln-immunized calves. Collectively, these data show the efficacy of a transfected HlGST-Cln B. bovis parasite to induce detectable anti-glutathione-S-transferase antibodies and a reduction in tick size and fecundity of R. microplus feeding in experimentally inoculated animals.

Spatial and Dietary Overlap Creates Potential for Competition between Red Snapper (Lutjanus campechanus) and Vermilion snapper (Rhomboplites aurorubens).

Understanding the complex nature of direct and indirect species interactions is a critical precursor to successful resource management. In the northern Gulf of Mexico fisheries ecosystem, red snapper (Lutjanus campechanus) and vermilion snapper (Rhomboplites aurorubens) are two commercially harvested species within a larger reef fish complex. These two species share similar habitats and diets; however, little is known about how these species partition habitat and dietary resources. In this study we examined the extent of spatial and dietary overlap between red snapper and vermilion snapper, and experimentally compared their feeding behavior. Field data from multiple gear types demonstrates that red snapper and vermilion snapper frequently cohabited reefs in the northern Gulf of Mexico, and Pianka's niche overlap indices suggest significantly overlapping diets. Experimental manipulations show that red snapper are the dominant forager of the two species, as red snapper foraging alone ate more shrimp per fish than vermilion snapper in both the single species (p = 0.003) and mixed species (p = 0.02) treatments. In addition, red snapper ate significantly more shrimp per fish in the mixed species treatment than in the single species treatment (p = 0.04). Vermilion snapper shrimp consumption per fish did not differ significantly between mixed and single species treatments. Cumulatively, our results suggest that spatial and dietary overlap could lead to competition between red and vermilion snapper in the study area; however, conclusively determining the existence of such competition would require further research.

Characterization of a Mycobacterium avium subsp. avium operon associated with virulence and drug detoxification.

The lprG-p55 operon of Mycobacterium tuberculosis and Mycobacterium bovis is involved in the transport of toxic compounds. P55 is an efflux pump that provides resistance to several drugs, while LprG is a lipoprotein that modulates the host's immune response against mycobacteria. The knockout mutation of this operon severely reduces the replication of both mycobacterial species during infection in mice and increases susceptibility to toxic compounds. In order to gain insight into the function of LprG in the Mycobacterium avium complex, in this study, we assayed the effect of the deletion of lprG gene in the D4ER strain of Mycobacterium avium subsp. avium. The replacement of lprG gene with a hygromycin cassette caused a polar effect on the expression of p55. Also, a twofold decrease in ethidium bromide susceptibility was observed and the resistance to the antibiotics rifampicin, amikacin, linezolid, and rifabutin was impaired in the mutant strain. In addition, the mutation decreased the virulence of the bacteria in macrophages in vitro and in a mice model in vivo. These findings clearly indicate that functional LprG and P55 are necessary for the correct transport of toxic compounds and for the survival of MAA in vitro and in vivo.