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Cholera is highly endemic in many sub-Saharan African countries. The bacterium Vibrio cholerae is responsible for this severe dehydrating diarrheal disease that accounts for over 100,000 deaths each year globally. In recent years, the pathogen has been found to invade intestinal layers and translocate into the bloodstream of humans. The non-toxigenic strains of V. cholerae (non-O1/O139), also known as NOVC, which do not cause epidemic or pandemic cases of cholera, are the major culprits of V. cholerae bacteremia. In non-cholera-endemic regions, clinical reports on NOVC infection have been noted over the past few decades, particularly in Europe and America. Although low-middle-income countries are most susceptible to cholera infections because of challenges with access to clean water and inappropriate sanitation issues, just a few cases of V. cholerae bloodstream infections have been reported. The lack of evidence-based research and surveillance of V. cholerae bacteremia in Africa may have significant clinical implications. This commentary summarizes the existing knowledge on the host risk factors, pathogenesis, and diagnostics of NOVC bacteremia.
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Streptococcus agalactiae infection is one of the major factors limiting the expansion of tilapia farming globally. In this study, we investigated the serotype distribution, virulence and antimicrobial resistance of S. agalactiae isolates from tilapia farmed in Lake Volta, Ghana. Isolates from 300 moribund fish were characterised by Gram staining, MALDI-TOF/MS and 16S rRNA sequencing. Serotype identification was based on multiplex polymerase chain reaction (PCR) amplification of the capsular polysaccharide genes. Detection of virulence genes (cfb, fbsA and cspA) and histopathology were used to infer the pathogenicity of the isolates. The susceptibility of isolates to antibiotics was tested using the Kirby-Bauer disk diffusion assay. All 32 isolates identified as S. agalactiae were of serotype Ia. This was notably different from isolates previously collected from the farms in 2017, which belonged to serotype Ib, suggesting a possible serotype replacement. The prevalence of the pathogen was related to the scale of farm operation, with large-scale farms showing higher S. agalactiae positivity. Data from histopathological analysis and PCR amplification of targeted virulence genes confirmed the virulence potential and ability of the isolates to cause systemic infection in tilapia. Except for gentamicin, the majority of the isolates were less resistant to the tested antibiotics. All isolates were fully sensitive to oxytetracycline, erythromycin, florfenicol, enrofloxacin, ampicillin and amoxicillin. This study has improved our understanding of the specific S. agalactiae serotypes circulating in Lake Volta and demonstrates the need for continuous monitoring to guide the use of antimicrobials and vaccines against streptococcal infections in Ghanaian aquaculture systems.
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Antibacterianos , Farmacorresistência Bacteriana , Doenças dos Peixes , Sorogrupo , Infecções Estreptocócicas , Streptococcus agalactiae , Animais , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/genética , Streptococcus agalactiae/patogenicidade , Gana/epidemiologia , Doenças dos Peixes/microbiologia , Infecções Estreptocócicas/veterinária , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/epidemiologia , Virulência , Antibacterianos/farmacologia , Lagos/microbiologia , Ciclídeos , AquiculturaRESUMO
Salmonella enterica are important foodborne bacterial pathogens globally associated with poultry. Exposure to Salmonella-contaminated eggs and egg-related products is a major risk for human salmonellosis. Presently, there is a huge data gap regarding the prevalence and circulating serovars of Salmonella in chicken eggs sold in Ghana. In this study, 2,304 eggs (pools of six per sample unit) collected from informal markets in Accra, Kumasi and Tamale, representing the three ecological belts across Ghana, were tested for Salmonella. Antimicrobial susceptibility testing and Whole Genome Sequencing (WGS) of the isolates were performed using standard microdilution protocols and the Illumina NextSeq platform, respectively. The total prevalence of Salmonella was 5.5% with a higher rate of contamination in eggshell (4.9%) over egg content (1.8%). The serovars identified were S. Ajiobo (n = 1), S. Chester (n = 6), S. Hader (n = 7), S. enteritidis (n = 2); and S. I 4:b:- (n = 8). WGS analysis revealed varied sequence types (STs) that were serovar specific. The S. I 4:b:- isolates had a novel ST (ST8938), suggesting a local origin. The two S. enteritidis isolates belonged to ST11 and were identified with an invasive lineage of a global epidemic clade. All isolates were susceptible to ampicillin, azithromycin, cefotaxime, ceftazidime, gentamicin, meropenem, and tigecycline. The phenotypic resistance profiles to seven antimicrobials: chloramphenicol (13%), ciprofloxacin (94%), and nalidixic acid (94%), colistin (13%), trimethoprim (50%) sulfamethoxazole (50%) and tetracycline (50%) corresponded with the presence of antimicrobial resistance (AMR) determinants including quinolones (gyrA (D87N), qnrB81), aminoglycosides (aadA1), (aph(3")-Ib aph(6)-Id), tetracyclines (tet(A)), phenicols (catA1), trimethoprim (dfrA14 and dfrA1). The S. enteritidis and S. Chester isolates were multidrug resistant (MDR). Several virulence factors were identified, notably cytolethal distending toxin (cdtB gene), rck, pef and spv that may promote host invasion and disease progression in humans. The findings from this study indicate the presence of multidrug resistant and virulent strains of Salmonella serovars in Ghanaian chicken eggs, with the potential to cause human infections. This is a critical baseline information that could be used for Salmonella risk assessment in the egg food chain to mitigate potential future outbreaks.
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Introduction: Gonorrhoea is a major public health concern. With the global emergence and spread of resistance to last-line antibiotic treatment options, gonorrhoea threatens to be untreatable in the future. Therefore, this study performed whole genome characterization of Neisseria gonorrhoeae collected in Ghana to identify lineages of circulating strains as well as their phenotypic and genotypic antimicrobial resistance (AMR) profiles. Methods: Whole genome sequencing (WGS) was performed on 56 isolates using both the Oxford Nanopore MinION and Illumina MiSeq sequencing platforms. The Comprehensive Antimicrobial Resistance Database (CARD) and PUBMLST.org/neisseria databases were used to catalogue chromosomal and plasmid genes implicated in AMR. The core genome multi-locus sequence typing (cgMLST) approach was used for comparative genomics analysis. Results and Discussion: In vitro resistance measured by the E-test method revealed 100%, 91.0% and 85.7% resistance to tetracycline, penicillin and ciprofloxacin, respectively. A total of 22 sequence types (STs) were identified by multilocus sequence typing (MLST), with ST-14422 (n = 10), ST-1927 (n = 8) and ST-11210 (n = 7) being the most prevalent. Six novel STs were also identified (ST-15634, 15636-15639 and 15641). All isolates harboured chromosomal AMR determinants that confer resistance to beta-lactam antimicrobials and tetracycline. A single cefixime-resistant strain, that belongs to N. gonorrhoeae multiantigen sequence type (NG-MAST) ST1407, a type associated with widespread cephalosporin resistance was identified. Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR), identified 29 unique sequence types, with ST-464 (n = 8) and the novel ST-3366 (n = 8) being the most prevalent. Notably, 20 of the 29 STs were novel, indicative of the unique nature of molecular AMR determinants in the Ghanaian strains. Plasmids were highly prevalent: pTetM and pblaTEM were found in 96% and 92% of isolates, respectively. The TEM-135 allele, which is an amino acid change away from producing a stable extended-spectrum ß-lactamase that could result in complete cephalosporin resistance, was identified in 28.5% of the isolates. Using WGS, we characterized N. gonorrhoeae strains from Ghana, giving a snapshot of the current state of gonococcal AMR in the country and highlighting the need for constant genomic surveillance.
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BACKGROUND: Community-academic partnerships are increasingly used in interventions to address health care disparities. Little is known about motivations and perceptions of participating community members. OBJECTIVES: To elicit community members' perspectives of involvement in a community-academic partnership to address implicit bias in health care. METHODS: With our partnering community organizer, we conducted one-on-one semistructured interviews and a follow-up group interview with participating community members to solicit experiences about involvement in an National Institutes of Health-funded clinician training; responses were organized using content analysis. RESULTS: Community members revealed that their participation was motivated by trust in our community organizer; they derived personal pride from participation in clinician training; the power differential between community members and clinicians in the training environment needed to be levelled. Our community organizer noted that the benefits of community-academic partnerships propagate to the larger community via community members' experiences. CONCLUSIONS: Community members note trust, pride, and power as important elements in community-academic partnership.
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Viés Implícito , Pesquisa Participativa Baseada na Comunidade , Humanos , Universidades , Relações Comunidade-Instituição , Comportamento CooperativoRESUMO
Hypervirulent Aeromonas hydrophila (vAh) has emerged as the etiologic agent of epidemic outbreaks of motile Aeromonas septicemia (MAS) in high-density aquaculture of farmed carp in China and catfish in the United States, which has caused millions of tons of lost fish. We conducted a global survey to better understand the evolution, geographical distribution, and phylogeny of vAh. Aeromonas isolates were isolated from fish that showed clinical symptoms of MAS, and pure cultures were screened for the ability to utilize myo-inositol as the sole carbon source. A total of 113 myo-inositol-utilizing bacterial strains were included in this study, including additional strains obtained from previously published culture collections. Based on a gyrB phylogeny, this collection included 66 A. hydrophila isolates, 48 of which were vAh. This collection also included five new vAh isolates from diseased Pangas catfish (Pangasius pangasius) and striped catfish (Pangasianodon hypophthalmus) obtained in Cambodia and Vietnam, respectively. Genome sequences were generated from representative vAh and non-vAh isolates to evaluate the potential for lateral genetic transfer of the myo-inositol catabolism pathway. Phylogenetic analyses of each of the nine genes required for myo-inositol utilization revealed the close affiliation of vAh strains regardless of geographic origin and suggested lateral genetic transfer of this catabolic pathway from an Enterobacter species. Prediction of virulence factors was conducted to determine differences between vAh and non-vAh strains in terms of virulence and secretion systems. Core genome phylogenetic analyses on vAh isolates and Aeromonas spp. disease isolates (55 in total) were conducted to evaluate the evolutionary relationships among vAh and other Aeromonas sp. isolates, which supported the clonal nature of vAh isolates. IMPORTANCE This global survey of vAh brought together scientists that study fish disease to evaluate the evolution, geographical distribution, phylogeny, and hosts of vAh and other Aeromonas sp. isolates. In addition to vAh isolates from China and the United States, four new vAh isolates were isolated from the lower Mekong River basin in Cambodia and Vietnam, indicating the significant threat of vAh to modern aquaculture and the need for improved biosecurity to prevent vAh spread.
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Recurrent epidemics of cholera denote robust adaptive mechanisms of Vibrio cholerae for ecological shifting and persistence despite variable stress conditions. Tracking the evolution of pathobiological traits requires comparative genomic studies of isolates from endemic areas. Here, we investigated the genetic differentiation among V. cholerae clinical and environmental isolates by highlighting the genomic divergence associated with gene decay, genome plasticity, and the acquisition of virulence and adaptive traits. The clinical isolates showed high phylogenetic relatedness due to a higher frequency of shared orthologs and fewer gene variants in contrast to the evolutionarily divergent environmental strains. Divergence of the environmental isolates is linked to extensive genomic rearrangements in regions containing mobile genetic elements resulting in numerous breakpoints, relocations, and insertions coupled with the loss of virulence determinants acf, zot, tcp, and ctx in the genomic islands. Also, four isolates possessed the CRISPR-Cas systems with spacers specific for Vibrio phages and plasmids. Genome synteny and homology analysis of the CRISPR-Cas systems suggest horizontal acquisition. The marked differences in the distribution of other phage and plasmid defense systems such as Zorya, DdmABC, DdmDE, and type-I Restriction Modification systems among the isolates indicated a higher propensity for plasmid or phage disseminated traits in the environmental isolates. Our results reveal that V. cholerae strains undergo extensive genomic rearrangements coupled with gene acquisition, reflecting their adaptation during ecological shifts and pathogenicity.
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INTRODUCTION: Infants are at risk of Staphylococcus aureus (S. aureus) colonization and infection. The aim of this study was to investigate S. aureus and methicillin-resistant S. aureus (MRSA) colonization among infants, including the prevalence, predictors of colonization, and antibiogram. METHODOLOGY: The study was cross-sectional, and involved infants aged less than one year recruited at the Princess Marie Louise Children's Hospital in Accra, Ghana. Sociodemographic and clinical data of the participants were gathered with a structured questionnaire. Nasal swabs were also obtained from them and bacteriologically cultured. S. aureus was confirmed with the coagulase test, and MRSA was confirmed by polymerase chain reaction (PCR) of the mecA gene. Antimicrobial susceptibility testing of S. aureus was done using the Kirby-Bauer method. RESULTS: The carriage prevalence of S. aureus and MRSA were 34.9% (45/129) and 17.10% (22/129), respectively. Colonization with coagulase-negative Staphylococci (CoNS) was protective of both S. aureus (OR = 0.008; p < 0.001) and MRSA (OR = 0.052; p = 0.005) carriage. Maintenance of good hand hygiene prevented S. aureus carriage (OR = 0.16; p < 0.001). S. aureus resistance to antibiotics decreased across penicillin (96%), trimethoprim-sulfamethoxazole (61%), tetracycline (61%), erythromycin (39%), gentamicin (39%), fusidic acid (26%), rifampicin (17%), clindamycin (7%), and linezolid (0%); 68.8% S. aureus were multidrug resistant. CONCLUSIONS: S. aureus and MRSA prevalence were high among the infants. Colonization with CoNS and good hand hygiene maintenance were predictive of MRSA and methicillin-sensitive S. aureus (MSSA) colonization, respectively.
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Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Clindamicina , Coagulase , Estudos Transversais , Eritromicina , Ácido Fusídico , Gentamicinas , Gana/epidemiologia , Hospitais , Humanos , Lactente , Linezolida , Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Prevalência , Rifampina , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/genética , Tetraciclinas , Combinação Trimetoprima e SulfametoxazolRESUMO
Objective: To examine the association between animal contact (primarily dogs and cats) and non-malarial fever, as well as with secondary symptoms of headache, nausea, vomiting, and cough, in 687 children in Greater Accra Region, Ghana. Design: Cross-sectional study of acute febrile illness among children aged 1-15 years old between October 2016 and August 2017. Setting: Ledzokuku-Krowor Municipal Assembly (LEKMA) Hospital, Teshie, Greater Accra Region. Participants: The study included children with acute fever, defined as a measured temperature of greater than 37.5°C, occurring less than seven days before the hospital visit, and afebrile children as controls. Main outcome measures: Measured fever, self-reported fever, and secondary symptoms, each adjusting for patient household characteristics. Results: Animal contact was neither associated with measured fever (OR = 1.04, 95% CI 0.73-1.49) nor with self-reported fever (OR = 0.97, 95% CI 0.68-1.39). Animal contact was associated with headache (OR = 3.26, 95% CI 2.23-4.77, P < .01) and nausea (OR = 3.05, 95% CI 1.99-4.68, P < .01), but not with vomiting or cough. Additional models that used alternate inclusion criteria to define non-malarial fever yielded similar results. Several bacterial zoonoses that could plausibly have been transmitted by dogs and cats were diagnosed in the study population. Conclusion: These findings suggest the need for future studies to evaluate animal contact as a risk factor for bacterial zoonoses that may serve as an etiological driver of acute febrile illness. Funding: no external funding.
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Doenças do Gato , Doenças do Cão , Humanos , Animais , Gatos , Cães , Zoonoses Bacterianas , Gana/epidemiologia , Estudos Transversais , Tosse , Febre/epidemiologia , Febre/etiologia , Náusea/complicações , Vômito/etiologia , Vômito/complicações , CefaleiaRESUMO
AIM: To investigate the epidemiology of S. aureus and MRSA nasal carriage among people with diabetes at the Korle Bu Teaching Hospital in Accra, including the prevalence, predictors of carriage, and antibiotic resistance. METHODOLOGY: This study was cross-sectional, involving 300 diabetes patients and 106 non-diabetic individuals. Swab specimens of the nares were obtained from the participants and bacteriologically-cultured. Identification and characterization of S. aureus and MRSA were based on standard bacteriological methods; antimicrobial susceptibility testing was by the Kirby-Bauer method. RESULTS: The prevalence of staphylococcal carriage, the diabetes group relative to the non-diabetes group, were 31.0% and 10.4% (S. aureus), and 3.3% and 0.0% (MRSA). Presence of diabetes predisposed to S. aureus carriage, but not MRSA nor coagulase-negative staphylococci (CoNS) carriage (OR = 3.88; p < 0.0001). Colonization with CoNS was protective of S. aureus (OR = 0.039, p < 0.001) and MRSA (OR = 0.115, p = 0.043) colonization among the diabetics. The antimicrobial resistance patterns recorded among the S. aureus isolated from the diabetic individuals relative to the non-diabetics were as follows: penicillin (95% vs. 91%), tetracycline (37% vs. 27%), cotrimoxazole (30% vs. 36%), erythromycin (17% vs. 0%), norfloxacin (13% vs. 0%), clindamycin (12% vs. 0%), gentamicin (9% vs. 0%), fusidic acid (10% vs. 9%), linezolid (4% vs. 0%), and rifampicin (5% vs. 0%). The proportion of multidrug resistant S. aureus was 41% (n = 38) in the diabetes group and 0% in the non-diabetes group; this difference was statistically significant (p = 0.01). CONCLUSIONS: The presence of diabetes predisposed the participants to S. aureus carriage by almost four folds, but not MRSA carriage. Colonization with CoNS was protective of S. aureus and MRSA carriage in the diabetes group. Finally, linezolid remains a good therapeutic agent for anti-MRSA therapy.
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Complicações do Diabetes/microbiologia , Diabetes Mellitus/microbiologia , Farmacorresistência Bacteriana Múltipla , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Adolescente , Adulto , Antibacterianos/uso terapêutico , Portador Sadio , Clindamicina/uso terapêutico , Estudos Transversais , Complicações do Diabetes/diagnóstico , Complicações do Diabetes/tratamento farmacológico , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/tratamento farmacológico , Eritromicina/uso terapêutico , Feminino , Ácido Fusídico/uso terapêutico , Gentamicinas/uso terapêutico , Humanos , Linezolida/uso terapêutico , Masculino , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Cavidade Nasal/microbiologia , Norfloxacino/uso terapêutico , Penicilinas/uso terapêutico , Rifampina/uso terapêutico , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/tratamento farmacológico , Tetraciclina/uso terapêutico , Combinação Trimetoprima e Sulfametoxazol/uso terapêuticoRESUMO
AIM: This study investigated the spectrum of bacteria infecting the ulcers of individuals with diabetes at the Korle Bu Teaching Hospital in Accra, Ghana, focusing on Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA), with respect to their prevalence, factors predisposing to their infection of the ulcers, and antimicrobial resistance patterns. METHODOLOGY: This cross-sectional study was conducted at The Ulcer Clinic, Department of Surgery, Korle Bu Teaching Hospital, involving 100 diabetic foot ulcer patients. The ulcer of each study participant was swabbed and cultured bacteriologically, following standard procedures. Antimicrobial susceptibility testing was done for all S. aureus isolated, using the Kirby-Bauer method. RESULTS: In total, 96% of the participants had their ulcers infected-32.3% (n = 31) of these had their ulcers infected with one bacterium, 47.9% (n = 46) with two bacteria, 18.8% (n = 18) with three bacteria, and 1.0% (n = 1) with four bacteria. The prevalence of S. aureus and MRSA were 19% and 6%, respectively. The distribution of the other bacteria was as follows: coagulase-negative Staphylococci (CoNS) (54%), Escherichia coli (24%), Pseudomonas spp. (19%), Citrobacter koseri and Morganella morgana (12% each), Klebsiella oxytoca (11%), Proteus vulgaris (8%), Enterococcus spp. (6%), Klebsiella pneumoniae (5%), Proteus mirabilis and Enterobacter spp. (4%), Klebsiella spp. (2%), and Streptococcus spp. (1%). The resistance rates of S. aureus decreased across penicillin (100%, n = 19), tetracycline (47.4%, n = 9), cotrimoxazole (42.1%, n = 8), cefoxitin (31.6%, n = 6), erythromycin and clindamycin (26.3% each, n = 5), norfloxacin and gentamicin (15.8% each, n = 3), rifampicin (10.5%, n = 2), linezolid (5.3%, n = 1), and fusidic acid (0.0%, n = 0). The proportion of multidrug resistance was 47.4% (n = 9). Except for foot ulcer infection with coagulase-negative Staphylococci, which was protective of S. aureus infection of the ulcers (OR = 0.029, p = 0.001, 95% CI = 0.004-0.231), no predictor of S. aureus, MRSA, or polymicrobial ulcer infection was identified. CONCLUSIONS: The prevalence of S. aureus and MRSA infection of the diabetic foot ulcers were high, but lower than those of the predominant infector, coagulase-negative Staphylococci and the next highest infecting agent, E. coli. Diabetic foot ulcers' infection with coagulase-negative Staphylococci protected against their infection with S. aureus. The prevalence of multidrug resistance was high, highlighting the need to further intensify antimicrobial stewardship programmes.
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Drugs targeting DNA and RNA in mammalian cells or viruses can also affect bacteria present in the host and thereby induce the bacterial SOS system. This has the potential to increase mutagenesis and the development of antimicrobial resistance (AMR). Here, we have examined nucleoside analogues (NAs) commonly used in anti-viral and anti-cancer therapies for potential effects on mutagenesis in Escherichia coli, using the rifampicin mutagenicity assay. To further explore the mode of action of the NAs, we applied E. coli deletion mutants, a peptide inhibiting Pol V (APIM-peptide) and metabolome and proteome analyses. Five out of the thirteen NAs examined, including three nucleoside reverse transcriptase inhibitors (NRTIs) and two anti-cancer drugs, increased the mutation frequency in E. coli by more than 25-fold at doses that were within reported plasma concentration range (Pl.CR), but that did not affect bacterial growth. We show that the SOS response is induced and that the increase in mutation frequency is mediated by the TLS polymerase Pol V. Quantitative mass spectrometry-based metabolite profiling did not reveal large changes in nucleoside phosphate or other central carbon metabolite pools, which suggests that the SOS induction is an effect of increased replicative stress. Our results suggest that NAs/NRTIs can contribute to the development of AMR and that drugs inhibiting Pol V can reverse this mutagenesis.
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DNA Polimerase Dirigida por DNA/genética , Proteínas de Escherichia coli/genética , Mutagênese/efeitos dos fármacos , Nucleosídeos/análogos & derivados , Nucleosídeos/farmacologia , Antineoplásicos/farmacologia , Antivirais/farmacologia , Testes de Sensibilidade Microbiana/métodos , Mutagênese/fisiologia , Estavudina/análogos & derivados , Estavudina/farmacologiaRESUMO
Sepsis is a life-threatening systemic illness attributed to a dysregulated host response to infection. Sepsis is a global burden killing ~11 million persons annually. In December 2019, a novel pneumonia condition termed coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged and has resulted in more than 1,535,982 deaths globally as of 8th December 2020. These two conditions share many pathophysiological and clinical features. Notably, both sepsis and COVID-19 patients experience consumptive thrombocytopenia, haemolytic anaemia, vascular microthrombosis, multi-organ dysfunction syndrome, coagulopathy, septic shock, respiratory failure, fever, leukopenia, hypotension, leukocytosis, high cytokine production and high predisposition to opportunistic infections. Considering the parallels in the immunopathogenesis and pathophysiological manifestations of sepsis and COVID-19, it is highly likely that sepsis care, which has a well-established history in most health systems, could inform on COVID-19 management. In view of this, the present perspective compares the immunopathogenesis and pathophysiology of COVID-19 and non-SARS-CoV-2 induced sepsis, and lessons from sepsis that can be applicable to COVID-19 management.
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COVID-19/diagnóstico , SARS-CoV-2/fisiologia , Sepse/diagnóstico , Animais , COVID-19/terapia , Síndrome da Liberação de Citocina , Humanos , Hipovolemia , Tolerância Imunológica , Insuficiência Respiratória , Sepse/terapia , TromboseRESUMO
In late 2018, unusual patterns of very high mortality (>50% production) were reported in intensive tilapia cage culture systems across Lake Volta in Ghana. Samples of fish and fry were collected and analysed from two affected farms between October 2018 and February 2019. Affected fish showed darkening, erratic swimming and abdominal distension with associated ascites. Histopathological observations of tissues taken from moribund fish at different farms revealed lesions indicative of viral infection. These included haematopoietic cell nuclear and cytoplasmic pleomorphism with marginalization of chromatin and fine granulation. Transmission electron microscopy showed cells containing conspicuous virions with typical iridovirus morphology, that is enveloped, with icosahedral and/or polyhedral geometries and with a diameter c.160 nm. PCR confirmation and DNA sequencing identified the virions as infectious spleen and kidney necrosis virus (ISKNV). Samples of fry and older animals were all strongly positive for the presence of the virus by qPCR. All samples tested negative for TiLV and nodavirus by qPCR. All samples collected from farms prior to the mortality event were negative for ISKNV. Follow-up testing of fish and fry sampled from 5 additional sites in July 2019 showed all farms had fish that were PCR-positive for ISKNV, whether there was active disease on the farm or not, demonstrating the disease was endemic to farms all over Lake Volta by that point. The results suggest that ISKNV was the cause of disease on the investigated farms and likely had a primary role in the mortality events. A common observation of coinfections with Streptococcus agalactiae and other tilapia bacterial pathogens further suggests that these may interact to cause severe pathology, particularly in larger fish. Results demonstrate that there are a range of potential threats to the sustainability of tilapia aquaculture that need to be guarded against.
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Ciclídeos , Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/diagnóstico , Iridoviridae/isolamento & purificação , Animais , Aquicultura , Infecções por Vírus de DNA/diagnóstico , Infecções por Vírus de DNA/virologia , Doenças dos Peixes/virologia , GanaRESUMO
Cholera remains a major global public health threat and continuous emergence of new Vibrio cholerae strains is of major concern. We conducted a molecular epidemiological study to detect virulence markers and antimicrobial resistance patterns of V. cholerae isolates obtained from the 2012-2015 cholera outbreaks in Ghana. Archived clinical isolates obtained from the 2012, 2014 and 2015 cholera outbreaks in Ghana were revived by culture and subjected to microscopy, biochemical identification, serotyping, antibiotic susceptibility testing, molecular detection of distinct virulence factors and Multi-Locus Variable-Number of Tandem-Repeat Analysis (MLVA). Of 277 isolates analysed, 168 (60.6%) were confirmed to be V. cholerae and 109 (39.4%) isolates constituted other bacteria (Escherichia coli, Aeromonas sobria, Pseudomonas aeruginosa, Enterobacter cloacae and Enterococci faecalis). Serotyping the V. cholerae isolates identified 151 (89.9%) as Ogawa, 3 (1.8%) as Inaba and 14 (8.3%) as non-O1/O139 serogroup. The O1 serogroup isolates (154/168, 91.7%) carried the cholera toxin ctxB gene as detected by PCR. Additional virulence genes detected include zot, tcpA, ace, rtxC, toxR, rtxA, tcpP, hlyA and tagA. The most common and rare virulence factors detected among the isolates were rtxC (165 isolates) and tcpP (50 isolates) respectively. All isolates from 2014 and 2015 were multidrug resistant against the selected antibiotics. MLVA differentiated the isolates into 2 large unique clones A and B, with each predominating in a particular year. Spatial analysis showed clustering of most isolates at Ablekuma sub-district. Identification of several virulence genes among the two different genotypes of V. cholerae isolates and resistance to first- and second-line antibiotics, calls for scaleup of preventive strategies to reduce transmission, and strengthening of public health laboratories for rapid antimicrobial susceptibility testing to guide accurate treatment. Our findings support the current WHO licensed cholera vaccines which include both O1 Inaba and Ogawa serotypes.
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Cólera/epidemiologia , Vibrio cholerae/metabolismo , Antibacterianos/farmacologia , Cólera/diagnóstico , Cólera/microbiologia , Toxina da Cólera/genética , Toxina da Cólera/metabolismo , Surtos de Doenças , Farmacorresistência Bacteriana Múltipla/genética , Gana/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Filogenia , Sorogrupo , Sequências de Repetição em Tandem/genética , Vibrio cholerae/classificação , Vibrio cholerae/isolamento & purificação , Vibrio cholerae/patogenicidade , Virulência/genéticaRESUMO
The aim of this study was to investigate S. aureus carriage among children with sickle cell disease (SCD), including the prevalence, risk factors, and antibiotic resistance. The study was cross-sectional, and involved 120 children with SCD recruited at the Princess Marie Louise Children's Hospital (PML) in Accra and 100 apparently healthy children from environs of the hospital. Nasal swab samples were collected from the study participants and cultured for bacteria. Confirmation of S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) isolates were done using the tube coagulase test and mecA polymerase chain reaction, respectively. All the S. aureus isolates were tested against standard antimicrobial agents using the Kirby-Bauer method. A structured questionnaire was used to obtain the socio-demographic and clinical data of the study participants. Binary logistic regression was used to identify determinants of S. aureus and MRSA carriage among the study participants. The nasal carriage prevalence of S. aureus was 33.3% (n = 40) and 10% (n = 10) among the participants of the SCD and control groups, respectively. As regards MRSA nasal carriage prevalence, the respective values were 3.33% (n = 4) and 0.00% (n = 0). SCD was significantly associated with S. aureus colonization (p < 0.0001, OR = 4.045), but not MRSA colonization (p = 0.128). In the SCD group, the significant predictors of S. aureus carriage were increasing age (p = 0.003; OR = 1.275) and living in self-contained apartments (p = 0.033; OR = 3.632), whereas male gender (p = 0.018; OR = 0.344) and the practice of self-medication (p = 0.039; OR = 0.233) were protective of S. aureus carriage. In the control group, a history of hospitalization in the past year was a risk factor for the carriage of S. aureus (p = 0.048; OR = 14.333). Among the participants of the SCD and control groups, respectively, the resistance prevalence recorded by S. aureus against the various antibiotics investigated were penicillin (100% each), cotrimoxazole (27.5% vs. 20%), tetracycline (25% vs. 50%), rifampicin (82.5% vs. 50%), erythromycin (30% vs. 20%), clindamycin (32.5% vs. 50%), gentamicin (7.5% vs. 20%), cefoxitin (27.5% vs. 20%), linezolid (30% vs. 40%), and fusidic acid (95% vs. 80%). The proportion of S. aureus isolates that were multidrug resistant (MDR) was 92.5% (37/40) in the SCD group and 100% (10/10) in the control group.
RESUMO
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) poses a public health threat owing to its extensive resistance to antibiotics, association with persistent outbreaks, and markedly increased healthcare costs. Moreover, HIV-infected individuals are at a greater risk for colonization with MRSA, and may act as reservoirs for subsequent transmission to other individuals. In Ghana, little is known about MRSA in relation to at-risk populations, such as HIV-infected children. The aim of this study was to investigate nasal carriage of S. aureus and MRSA among HIV-infected children in Accra, including the prevalence, risk factors and antibiotic resistance. METHODOLOGY: The study was cross-sectional, and involved 107 children with HIV infection and an equal number of sex- and age group- matched apparently healthy controls recruited from the Princess Marie Louis Children's Hospital in Accra. Nasal swab specimens were collected from the study participants and cultured for bacteria. S. aureus isolates were confirmed by the coagulase test while MRSA was confirmed by PCR of the mecA gene. Antimicrobial susceptibility testing of S. aureus isolates was done by the Kirby Bauer method. A structured questionnaire was used to collect data on demographic, household and clinical features of the study participants. A logistic regression analysis was performed to identify determinants of S. aureus and MRSA carriage among participants of both study groups. RESULTS: The carriage prevalence of S. aureus and MRSA were 44.9% (48) and 5.6% (6), respectively, among the HIV-infected individuals, and the corresponding values within the control group were 23.4% (25) and 0.9% (1). There was a significant association between HIV infection and S. aureus colonization (p < 0.001), but not MRSA colonization (p = 0.055). The main predictor of S. aureus colonization in both study groups was absence of colonization with coagulase negative staphylococcus (p < 0.001). Furthermore, the main predictor of MRSA colonization was regular hand washing with soap (p = 0.043); this was observed among HIV-infected individuals but not the control group. The proportion of S. aureus isolates that were multidrug resistant was 62.3% (33/53) in the HIV-infected group and 80% (20/25) in the control group (p = 0.192). CONCLUSIONS: HIV infection is a risk factor for nasal colonization of S. aureus among children in Accra but may not be for MRSA. Both the HIV-infected and uninfected children are reservoirs of multidrug resistant S. aureus. Demographic, household and clinical features appear to have little or no relationship with S. aureus and MRSA colonization in the study children.
RESUMO
Sepsis is a debilitating clinical syndrome of systemic inflammation in response to microorganisms especially Gram-positive and Gram-negative bacteria. A minority of sepsis cases could be due to non-pathogenic insult such as trauma. Much of the tissue and organ injury observed among septic patients is a consequence of the inflammatory response. The search for effective treatments of sepsis has led to several studies by different research groups across the globe. Although many targets and molecules have been identified, there is still no effective treatment for sepsis. The aim of this report is to review the literature on drugs and drug candidates against sepsis and how they modulate the expression of inflammatory genes. Many compounds have been identified to regulate inflammatory gene expression by interacting with targets such as topoisomerase 1 and nuclear factor kappa B, which regulate the production of pro- and anti-inflammatory cytokines. Even though these compounds appear promising as potential drugs against sepsis, no effective therapies have been discovered to date and thus the fight against sepsis continues.
Assuntos
Anti-Inflamatórios/farmacologia , Regulação da Expressão Gênica , Inflamação/genética , Sepse/genética , Animais , Descoberta de Drogas , HumanosRESUMO
We report new molecular evidence of locally acquired dengue virus infections in Ghana. We detected dengue viral RNA among children with suspected malaria by using a multipathogen real-time PCR. Subsequent sequence analysis revealed a close relationship with dengue virus serotype 2, which was implicated in a 2016 outbreak in Burkina Faso.