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1.
Nat Prod Res ; : 1-9, 2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38293715

ABSTRACT

AIMS: In this study, five essential oils (EOs) from different species of Lavandula hybrida abrialis, for Lavandula hybrida R.C., Lavandula hybrida 'super A', Lavandula hybrida 'super Z' and Lavandula vera and its hybrids Lavender were evaluated against 26 dust-isolated fungal strains from North Africa. METHODS AND RESULTS: The composition of the different EOs was determined from volume to dry weight. The photochemical analyses were performed via gas chromatography (GC). The cytotoxic effect of five lavender EOs on human epithelial colorectal adenocarcinoma cells (Caco-2) cell line was done. A total of 26 strains of filamentous fungi including Aspergillus spp., Botrytis cinerea, Ceriporia spp., Fusarium spp. and Penicillium glabrum were isolated from sand dust samples via molecular diagnostic tool of PCR. Fungal strains with the lowest minimal lethal concentration (MLC) were Penicillium glabrum, Ceriporia spp. and a strain of Aspergillus spp. CONCLUSIONS: More studies are needed to verify the activity of this EO against more different fungal species, and determine the active ingredients.Significance and impact of study: MIC of the antifungal efficacy relating to EOs was evaluated. The EOs tests showed no cytotoxic effect at very low concentrations, ranging from 0.03% (IC50 0.9132 mg/mL) (L. hybrid Abrialis) to 0.001% (IC50 1.631 mg/mL) (L. hybrid R.C.).

2.
J Infect Dev Ctries ; 17(4): 550-558, 2023 04 30.
Article in English | MEDLINE | ID: mdl-37159900

ABSTRACT

INTRODUCTION: Candida spp. are responsible for infections ranging from local to systemic, and resistance to antifungal first-line therapy is increasing in non-albicans Candida species. We aimed to determine the etiology of candidiasis and the antifungal resistance of Candida spp. isolated in Hue hospitals, Central-Vietnam. METHODS: Species identification was performed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry supported by fungal internal-transcribed-spacer amplification and sequencing. Antifungal susceptibility testing was performed by disk diffusion method and minimum inhibitory concentrations of azoles, caspofungin, and amphotericin B against C. tropicalis were determined by broth microdilution. Polymorphism of erg11 gene associated with fluconazole resistance was carried out by polymerase chain reaction and sequencing. Multilocus sequence typing (MLST) was used for typing selected C. albicans isolates. RESULTS: Overall, 196 Candida isolates were detected, mostly C. albicans (48%), followed by C. tropicalis (16%), C. parapsilosis (11%), C. glabrata (9%), C. orthopsilosis (6%) and to a lesser extent another eight species. High rates of resistance to fluconazole and voriconazole (18.8%) were observed in C. tropicalis with five isolates co-resistant to both agents. Y132F and S154F missense mutations in the ERG11 protein were associated with fluconazole-resistance in C. tropicalis (67.7%). Resistance to caspofungin was found in one isolate of C. albicans. MLST identified a polyclonal population of C. albicans with multiple diploid sequence types, and with few lineages showing potential nosocomial spread. CONCLUSIONS: Resistance to triazole agents should be considered in C. tropicalis infections in the studied hospitals, and surveillance measures taken to avoid Candida diffusion.


Subject(s)
Azoles , Candida albicans , Azoles/pharmacology , Fluconazole , Antifungal Agents/pharmacology , Caspofungin , Multilocus Sequence Typing , Vietnam/epidemiology , Candida/genetics , Hospitals
3.
Microorganisms ; 9(11)2021 Nov 18.
Article in English | MEDLINE | ID: mdl-34835509

ABSTRACT

The relationship between the multidrug-resistant (MDR) phenotype and biofilm-forming capacity has been a topic of extensive interest among biomedical scientists, as these two factors may have significant influence on the outcomes of infections. The aim of the present study was to establish a possible relationship between biofilm-forming capacity and the antibiotic-resistant phenotype in clinical Acinetobacter baumannii (A. baumannii) isolates. A total of n = 309 isolates were included in this study. Antimicrobial susceptibility testing and the phenotypic detection of resistance determinants were carried out. The capacity of isolates to produce biofilms was assessed using a crystal violet microtiter-plate-based method. Resistance rates were highest for ciprofloxacin (71.19%; n = 220), levofloxacin (n = 68.61%; n = 212), and trimethoprim-sulfamethoxazole (n = 66.02%; n = 209); 42.72% (n = 132) of isolates were classified as MDR; 22.65% (n = 70) of tested isolates were positive in the modified Hodge-test; the overexpression of efflux pumps had significant effects on the susceptibilities of meropenem, gentamicin, and ciprofloxacin in 14.24% (n = 44), 6.05% (n = 19), and 27.51% (n = 85), respectively; 9.39% (n = 29), 12.29% (n = 38), 22.97% (n = 71), and 55.35% (n = 170) of isolates were non-biofilm-producing and weak, moderate, and strong biofilm producers, respectively. A numerical, but statistically not significant, difference was identified between the MDR and non-MDR isolates regarding their biofilm-forming capacity (MDR: 0.495 ± 0.309 vs. non-MDR: 0.545 ± 0.283; p = 0.072), and no association was seen between resistance to individual antibiotics and biofilm formation. Based on numerical trends, MER-resistant isolates were the strongest biofilm producers (p = 0.067). Our study emphasizes the need for additional experiments to assess the role biofilms have in the pathogenesis of A. baumannii infections.

4.
Nat Prod Res ; 35(24): 5674-5680, 2021 Dec.
Article in English | MEDLINE | ID: mdl-32975126

ABSTRACT

In the prevention of epidemic and pandemic emerging and neglected viral infections, natural products are an important source of lead compounds. Hornstedtia bella Skornickis is a rhizomatous herb growing in the forest of central Vietnam. Hornstedtia bella essential oil (Hb EO) was recently characterised by our group as endowed of antimicrobial activity against Staphylococcus aureus Methicillin-Resistant strains. Here, we describe for the first time the evaluation of Hb EO against a spectrum of viruses responsible for important human diseases. Hb EO resulted active against Vaccinia virus (VV) (EC50 values 80 µg/mL), closely related to variola virus, causative agent of smallpox. Hb EO was able to strongly reduce the viral VV titer in cell-based assay at not cytotoxic concentration and its potential mode of action was characterised by virucidal activity evaluation followed by time-of-addition assay. Furthermore, Hb EO antiviral activity was implemented in a combination study with the mycophenolic acid.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Oils, Volatile , Zingiberaceae , Antiviral Agents/pharmacology , Humans , Oils, Volatile/pharmacology , Vaccinia virus
5.
J Infect Dev Ctries ; 14(9): 1054-1064, 2020 09 30.
Article in English | MEDLINE | ID: mdl-33031096

ABSTRACT

INTRODUCTION: The present study aimed to determine the chemical compositions and bioactivities of the essential oil of Atalantia sessiflora Guillaumin (A. sessiflora), including antibacterial, antimycotic, antitrichomonas, anti-inflammatory and antiviral effects. METHODOLOGY: The essential oil from leaves of A. sessiflora was extracted by hydrodistillation using a Clevenger apparatus. Chemical compositions of oil were identified by GC/MS. Antimicrobial and antitrichomonas activity were determined by the microdilution method; anti-inflammatory and antiviral were determined by the MTT method. RESULTS: The average yield of oil was 0.46 ± 0.01% (v/w, dry leaves). A number of 45 constituents were identified by GC/MS. The essential oil comprised four main components. The oil showed antimicrobial activities against Gram-positive strains as Staphylococcus; Gram-negative bacteria such as Klebsiella pneumoniae and Escherichia coli; and finally four Candida species. Enterococcus faecalis and Pseudomonas aeruginosa were least susceptible to the oil of A. sessiflora, as seen in their MIC and MLC values over 16% (v/v). Activity against Trichomonas vaginalis was also undertaken, showing IC50, IC90 and MLC values of 0.016, 0.03 and 0.06% (v/v) respectively, after 48 hours of incubation. The oil of A. sessiflora displayed activity against the nitric oxide generation with the IC50 of 95.94 ± 6.18 µg/mL. The oil was completely ineffective against tested viruses, ssRNA+, ssRNA-, dsRNA, and dsDNA viruses. CONCLUSIONS: This is the first yet comprehensive scientific report about the chemical compositions and pharmacological properties of the essential oil of A. sessiflora. Further studies should be done to evaluate the safety and toxicity of A. sessiflora oil.


Subject(s)
Anti-Infective Agents/pharmacology , Anti-Inflammatory Agents/pharmacology , Antitrichomonal Agents/pharmacology , Bacteria/drug effects , Oils, Volatile/pharmacology , Trichomonas vaginalis/drug effects , Animals , Anti-Infective Agents/isolation & purification , Anti-Inflammatory Agents/isolation & purification , Antitrichomonal Agents/isolation & purification , Antiviral Agents/pharmacology , Cell Line , Gas Chromatography-Mass Spectrometry , Humans , Mice , Microbial Sensitivity Tests , Nitric Oxide/analysis , Plant Extracts/pharmacology , Plant Leaves/chemistry , RAW 264.7 Cells , Rutaceae/chemistry , Vietnam , Viruses/drug effects
6.
Sci Rep ; 10(1): 12656, 2020 07 29.
Article in English | MEDLINE | ID: mdl-32728085

ABSTRACT

This study evidenced the presence of parasites in a cesspit of an aristocratic palace of nineteenth century in Sardinia (Italy) by the use of classical paleoparasitological techniques coupled with next-generation sequencing. Parasite eggs identified by microscopy included helminth genera pathogenic for humans and animals: the whipworm Trichuris sp., the roundworm Ascaris sp., the flatworm Dicrocoelium sp. and the fish tapeworm Diphyllobothrium sp. In addition, 18S rRNA metabarcoding and metagenomic sequencing analysis allowed the first description in Sardinia of aDNA of the human specific T. trichiura species and Ascaris genus. Their presence is important for understanding the health conditions, hygiene habits, agricultural practices and the diet of the local inhabitants in the period under study.


Subject(s)
DNA, Ancient/isolation & purification , Intestinal Diseases, Parasitic/history , Metagenomics/methods , RNA, Ribosomal, 18S/genetics , Trichuris/classification , Animals , DNA, Protozoan/genetics , DNA, Ribosomal/genetics , Geologic Sediments/parasitology , High-Throughput Nucleotide Sequencing , History, 19th Century , Host Specificity , Humans , Italy , Sequence Analysis, DNA , Trichuriasis/history , Trichuris/genetics , Trichuris/isolation & purification
7.
Antibiotics (Basel) ; 9(6)2020 Jun 18.
Article in English | MEDLINE | ID: mdl-32570731

ABSTRACT

The rapid emergence of drug-resistant strains and novel viruses have motivated the search for new anti-infectious agents. In this study, the chemical compositions and cytotoxicity, as well as the antibacterial, antifungal, antitrichomonas, and antiviral activities of essential oils from the leaves, rhizomes, and whole plant of Hornstedtia bella were investigated. The GC/MS analysis showed that ß-pinene, E-ß-caryophyllene, and α-humulene were found at high concentrations in the essential oils. The essential oils exhibited (i) inhibition against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis with minimum inhibitory concentrations (MIC) and minimum lethal concentration (MLC) values from 1 to 4% (v/v); (ii) MIC and MLC values from 2 to 16% (v/v) in Candida tropicalis and Candida parapsilosis; (iii) MIC and MLC values from 4 to 16% in Enterococcus faecalis; and (iv) MIC and MLC values from 8 to greater than or equal to 16% (v/v) in the remaining strains, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Candida albicans, and Candida glabrata. In antitrichomonas activity, the leaves and whole-plant oils of Hornstedtia bella possessed IC50, IC90, and MLC values of 0.008%, 0.016%, and 0.03% (v/v), respectively, whilst those of rhizomes oil had in turn, 0.004%, 0.008%, and 0.016% (v/v).Besides, the leaf oil showed a weak cytotoxicity against Vero 76 and MRC-5; meanwhile, rhizomes and whole-plant oils did not exert any toxic effects on cell monolayers. Finally, these oils were not active against EV-A71.

8.
Plants (Basel) ; 9(4)2020 Apr 03.
Article in English | MEDLINE | ID: mdl-32260297

ABSTRACT

:The present study aimed to determine the antimicrobial activity and chemical composition of leaves-extracted essential oil of Leoheo domatiophorus Chaowasku, D.T. Ngo and H.T. Le (L. domatiophorus), including antibacterial, antimycotic, antitrichomonas and antiviral effects. The essential oil was obtained using hydrodistillation, with an average yield of 0.34 ± 0.01% (v/w, dry leaves). There were 52 constituents as identified by GC/MS with available authentic standards, representing 96.74% of the entire leaves oil. The essential oil was comprised of three main components, namely viridiflorene (16.47%), (-)-δ-cadinene(15.58%) and γ-muurolene (8.00%). The oil showed good antimicrobial activities against several species: Gram-positive strains: Staphylococcus aureus (two strains) and Enterococcus faecalis, with Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) values from 0.25 to 1% (v/v); Gram-negative strains such as Escherichia coli (two strains), Pseudomonas aeruginosa (two strains) and Klebsiella pneumoniae, with MIC and MLC values between 2% and 8% (v/v); and finally Candida species, having MIC and MLC between 0.12 and 4% (v/v).Antitrichomonas activity of the oil was also undertaken, showing IC50, IC90 and MLC values of 0.008%, 0.016% and 0.03% (v/v), respectively, after 48h of incubation. The essential oil resultedin being completely ineffective against tested viruses, ssRNA+ (HIV-1, YFV, BVDV, Sb-1, CV-B4), ssRNA- (hRSVA2, VSV), dsRNA (Reo-1), and dsDNA (HSV-1, VV) viruses with EC50 values over 100 µg/mL. This is the first, yet comprehensive, scientific report about the chemical composition and pharmacological properties of the essential oil in L. domatiophorus.

9.
Antibiotics (Basel) ; 9(4)2020 Apr 24.
Article in English | MEDLINE | ID: mdl-32344551

ABSTRACT

The present study aimed to determine the bioactivities of essential oils extracted from the leaves of Paramignya trimera and Limnocitrus littoralis, including cytotoxicity, antiviral, antibacterial, antimycotic, and antitrichomonas effects. Herein, it was indicated that P. trimera and L. littoralis oils showed no cytotoxicity on normal cells, namely MT-4, BHK-21, MDBK, and Vero-76. P. trimera oil (i) exhibited the strongest inhibition against Staphylococcus aureus with MIC and MLC values of 2% (v/v); (ii) showed MIC and MLC values of 8% (v/v) in Candida parapsilosis; and (iii) in the remaining strains, showed MIC and MLC values greater than or equal to 16% (v/v). On the other hand, L. littoralis oil (i) displayed the strongest inhibition against Candida tropicalis and Candida parapsilosis with 2% (v/v) of MIC and MLC; and (ii) in the remaining strains, possessed MIC and MLC greater than or equal to 16% (v/v). In addition, antitrichomonas activities of the oils were undertaken, showing IC50, IC90, MLC values, respectively, at 0.016%, 0.03%, and 0.06% (v/v) from P. trimera, and 0.03%, 0.06%, 0.12% (v/v) from L. littoralis, after 48 h of incubation. The oils were completely ineffective against ssRNA+ (HIV-1, YFV, BVDV, Sb-1, CV-B4), ssRNA- (RSV, VSV), dsRNA (Reo-1), and dsDNA (HSV-1, VV) viruses. This is the first report describing the cytotoxicity, antiviral, antibacterial, antimycotic, and antitrichomonas activities of the essential oils of P. trimera and L. littoralis.

10.
Nat Prod Res ; 34(10): 1494-1497, 2020 May.
Article in English | MEDLINE | ID: mdl-30518254

ABSTRACT

The increasing incidence of resistance in tuberculosis and in atypical mycobacterial infections has prompted the search for alternative agents. We explored the antimycobacterial activity of Melaleuca cajuputi essential oil against tubercular and non tubercular mycobacterials isolates. The good activity observed towards M. cajuputi indicated that this essential oil might represent a promising antimicrobial agents, particularly in the management of microbial resistance.


Subject(s)
Anti-Bacterial Agents/pharmacology , Melaleuca/chemistry , Mycobacterium/drug effects , Anti-Bacterial Agents/chemistry , Microbial Sensitivity Tests , Mycobacterium tuberculosis/drug effects , Oils, Volatile/pharmacology
11.
J Infect Dev Ctries ; 12(7): 568-572, 2018 Jul 31.
Article in English | MEDLINE | ID: mdl-31954006

ABSTRACT

INTRODUCTION: This study aims to determine the genital HPV prevalence in reproductive-age women in Thua Thien Hue Province and comparison with HPV incidence in Hue University Hospital, Vietnam. METHODOLOGY: Cross-sectional study on 1,034 women of reproductive age from 11 communes/wards of three districts representing three different geographic areas of Thua Thien Hue Province, Vietnam. The hospital-based group included 102 women with cervicitis and/or abnormal Pap smear result coming to Hue University Hospital. Extracting DNA from cervical samples, performing the real-time PCR for detecting HPV and the reverse dot-blot assay for HPV typing in HPV positive cases. RESULTS: In community, HPV prevalence was 0.9%. Mean-age of HPV positive group was 37.9 ± 6.2 years. The detected low-risk types were 6 and 11; high-risk types include 16, 18, 33, 45, 52, and 58. Single-type infection was found in 66.7% of cases. In hospital-based group, 41.2% of women have been infected with HPV, 6 different HPV types were detected. HPV18 was the most frequent high-risk type (33.3%), followed by HPV16 (15.1%); HPV6 was the most frequent among low-risk HPV types (31.2%). Single-type infection rate was 33,3%; 2 and 3 types co-infections were 28,6% and 38.1%, respectively. CONCLUSIONS: Routine screening of high-risk HPV infection in women with symptomatic gynecologic infection and/or abnormal Pap smear appears to be benefit in early detection and prevention of cervical cancer, due to the high incidence of HPV infection.

12.
Infect Immun ; 84(10): 2953-62, 2016 10.
Article in English | MEDLINE | ID: mdl-27481240

ABSTRACT

Free-living amoebae of the genus Acanthamoeba can cause severe and chronic infections in humans, mainly localized in immune privileged sites, such as the brain and the eye. Monocytes/macrophages are thought to be involved in Acanthamoeba infections, but little is known about how these facultative parasites influence their functions. The aim of this work was to investigate the effects of Acanthamoeba on human monocytes/macrophages during the early phase of infection. Here, THP-1 cells, primary human monocytes isolated from peripheral blood, and human monocyte-derived macrophages were either coincubated with trophozoites of a clinical isolate of Acanthamoeba (genotype T4) or stimulated with amoeba-derived cell-free conditioned medium. Production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-6 [IL-6], and IL-12), anti-inflammatory cytokine (IL-10), and chemokine (IL-8) was evaluated at specific hours poststimulation (ranging from 1.5 h to 23 h). We showed that both Acanthamoeba trophozoites and soluble amoebic products induce an early anti-inflammatory monocyte-macrophage phenotype, characterized by significant production of IL-10; furthermore, challenge with either trophozoites or their soluble metabolites stimulate both proinflammatory cytokines and chemokine production, suggesting that this protozoan infection results from the early induction of coexisting, opposed immune responses. Results reported in this paper confirm that the production of proinflammatory cytokines and chemokines by monocytes and macrophages can play a role in the development of the inflammatory response during Acanthamoeba infections. Furthermore, we demonstrate for the first time that Acanthamoeba stimulates IL-10 production in human innate immune cells, which might both promote the immune evasion of Acanthamoeba and limit the induced inflammatory response.


Subject(s)
Acanthamoeba castellanii/immunology , Amebiasis/immunology , Cytokines/metabolism , Interleukin-10/metabolism , Leukocytes, Mononuclear/metabolism , Macrophages/metabolism , Analysis of Variance , Cells, Cultured , Enzyme-Linked Immunosorbent Assay , Genotype , Humans
13.
Libyan J Med ; 9(1): 25497, 2014.
Article in English | MEDLINE | ID: mdl-25216211

ABSTRACT

INTRODUCTION: Aeromonads of medical importance have been reported from numerous clinical, food, and water sources, but identification of genospecies and virulence factors of Aeromonas species from countries in North Africa and the Middle East are few. METHODS: In total 99 Aeromonas species isolates from different sources (diarrheal children [n=23], non-diarrheal children [n=16], untreated drinking water from wells [n=32], and chicken carcasses [n=28]) in Tripoli, Libya, were included in the present investigation. Genus identification was confirmed by biochemical analysis, and genospecies were determined using a combination of 16S rDNA variable region and gyrB sequence analysis. Polymerase chain reaction (PCR) was used to detect genes encoding toxins from 52 of the isolates. RESULTS: We identified 44 isolates (44%) as A. hydrophila (3 [3.0%] subspecies anaerogenes, 23 [23%] subspecies dhakensis, and 18 [18%] subspecies ranae); 27 isolates (27%) as A. veronii; 23 isolates (23%) as A. caviae; and 5 isolates (5.0%) as other genospecies. The genes encoding aerolysin (aer), cytolytic enterotoxin (act), and A. hydrophila isolate SSU enterotoxin (ast) were detected in 45 (87%), 4 (7.7%), and 9 (17%) of the 52 isolates tested, respectively. The gene encoding an extracellular lipase (alt) was not detected. CONCLUSION: The majority of aeromonads from Libya fall within three genospecies (i.e. A. hydrophila, A. veronii, and A. caviae), and genes coding for toxin production are common among them.


Subject(s)
Aeromonas/isolation & purification , Diarrhea/microbiology , Feces/microbiology , Meat/microbiology , Water Microbiology , Aeromonas/pathogenicity , Child , Child, Preschool , DNA, Ribosomal , Diarrhea/epidemiology , Humans , Infant , Libya/epidemiology , Phylogeny , Polymerase Chain Reaction , Virulence Factors
14.
Front Microbiol ; 4: 354, 2013.
Article in English | MEDLINE | ID: mdl-24348465

ABSTRACT

Cholera is still a major public health concern in many African countries. In Angola, after a decade of absence, cholera reemerged in 1987, spreading throughout the country until 1996, with outbreaks recurring in a seasonal pattern. In 2006 Angola was hit by one of the most severe outbreaks of the last decade, with ca. 240,000 cases reported. We analyzed 21 clinical strains isolated between 1992 and 2006 from several provinces throughout the country: Benguela, Bengo, Luanda, Cuando Cubango, and Cabinda. We used two multiplex PCR assays to investigate discriminatory mobile genetic elements (MGE) [Integrative Conjugative Elements (ICEs), VSP-II, GI12, GI14, GI15, K, and TLC phages] and we compared the profiles obtained with those of different reference V. cholerae O1 variants (prototypical, altered, and hybrid), responsible for the ongoing 7th pandemic. We also tested the strains for the presence of specific VSP-II variants and for the presence of a genomic island (GI) (WASA-1), correlated with the transmission of seventh pandemic cholera from Africa to South America. Based on the presence/absence of the analyzed genetic elements, five novel profiles were detected in the epidemic strains circulating in the 1990s. The most frequent profiles, F and G, were characterized by the absence of ICEs and the three GIs tested, and the presence of GI WASA-1 and the WASA variant of the VSP-II island. Our results identified unexpected variability within the 1990s epidemic, showing different rearrangements in a dynamic part of the genome not present in the prototypical V. cholerae O1 N16961. Moreover the 2006 strains differed from the current pandemic V. cholerae O1 strain. Taken together, our results highlight the role of horizontal gene transfer (HGT) in diversifying the genetic background of V. cholerae within a single epidemic.

15.
Trans R Soc Trop Med Hyg ; 107(8): 487-92, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23843558

ABSTRACT

BACKGROUND: Non-typhoidal Salmonella infections are an important public health problem in sub-Saharan Africa, especially among children and HIV-seropositive patients in whom they may cause invasive disease. METHODS: In order to better understand the epidemiology of Salmonella infections in southern Africa we typed, using serotyping, phage typing and multilocus sequence typing, 167 non-typhoidal Salmonella strains isolated from human clinical specimens during 1995-2000. RESULTS: The most common serovars were Salmonella Typhimurium DT56/ST313, Salmonella Enteritidis PT4 and Salmonella Isangi ST216. Isolates of Salmonella Isangi showed a multidrug-resistant phenotype that was resistant to extended-spectrum cephalosporins. Twelve new sequence types and six new serotypes of Salmonella were identified. CONCLUSIONS: Given the diversity detected in the study it seems likely that many new variants of S. enterica are extant in Zimbabwe and by implication across sub-Saharan Africa. We have demonstrated the presence in Zimbabwe of a multidrug-resistant strain of the serovar Salmonella Isangi and demonstrated the diversity of Salmonella circulating in one sub-Saharan African country. Further studies on the characteristics of Salmonella Isangi isolates from Zimbabwe, including plasmid typing and genotyping, are essential if effective control of the spread of this potential pathogen in sub-Saharan Africa is to be achieved.


Subject(s)
Bacterial Typing Techniques , Salmonella Infections/epidemiology , Salmonella Infections/microbiology , Salmonella enteritidis/isolation & purification , Salmonella typhimurium/isolation & purification , Bacteriophage Typing , Drug Resistance, Bacterial , Humans , Salmonella Infections/drug therapy , Salmonella enteritidis/drug effects , Salmonella typhimurium/drug effects , Serotyping , Zimbabwe/epidemiology
16.
J Infect Dev Ctries ; 7(3): 214-9, 2013 Mar 14.
Article in English | MEDLINE | ID: mdl-23492999

ABSTRACT

INTRODUCTION: Typical EPEC are considered a leading cause of diarrhoea in developing countries, while atypical EPEC have been isolated more frequently in developed areas. The actual geographic distribution of the two EPEC subgroups is controversial, since data can be highly influenced by laboratory resources. This study aimed to compare the distribution of typical and atypical EPEC among children in developed and developing countries, and to characterize the bacterial isolates, using a unique methodological approach. METHODOLOGY: A total of 1,049 E. coli were isolated from faeces of children with acute diarrhoea in Mozambique, Angola and Italy, and processed by PCR to assess the presence of a large panel of virulence genes. All isolates classified as EPEC were further characterized by evaluating adherence and capability to induce actin rearrangement on Hep-2 cells. RESULTS: Overall we isolated 59 EPEC, likewise distributed in the three countries, representing the 5.04%, 4.44% and 6.97% of all Mozambican, Angolan and Italian isolates, respectively. Nevertheless, the geographic distribution of the two EPEC subgroups was not homogeneous: in Italy we isolated 28 aEPEC but no tEPEC, while in Angola and Mozambique the percentage of the two subgroups was comparable. Twelve atypical EPEC were FAS positive and able to induce localized-like adherence on Hep-2 cells, but no correlation with the geographic origin of isolates was observed. CONCLUSION: Atypical EPEC are present in sub-Saharan areas in a percentage similar to that of typical strains, and are not mainly restricted to industrialized countries, as it was previously supposed.


Subject(s)
Enteropathogenic Escherichia coli/genetics , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Actins/metabolism , Angola/epidemiology , Bacterial Adhesion , Cell Line , Child, Preschool , DNA, Bacterial/genetics , Developed Countries , Developing Countries , Enteropathogenic Escherichia coli/isolation & purification , Enteropathogenic Escherichia coli/pathogenicity , Enteropathogenic Escherichia coli/physiology , Feces/microbiology , Female , Genotype , Hepatocytes/microbiology , Humans , Infant , Infant, Newborn , Italy/epidemiology , Male , Molecular Epidemiology , Mozambique/epidemiology , Polymerase Chain Reaction , Virulence Factors/genetics
17.
J Infect Dev Ctries ; 7(3): 235-42, 2013 Mar 14.
Article in English | MEDLINE | ID: mdl-23493002

ABSTRACT

INTRODUCTION: The influenza A(H1N1)pdm09 virus arrived in Vietnam in May 2009 via the United States and rapidly spread throughout the country. This study provides data on the viral diagnosis and molecular epidemiology of influenza A(H1N1)pdm09 virus isolated in Thua Thien Hue Province, central Vietnam. METHODOLOGY: Nasopharyngeal swabs and throat swabs from 53 clinically infected patients in the peak of the outbreak were processed for viral diagnosis by culture and RT-PCR. Sequencing of entire HA and NA genes of representative isolates and molecular epidemiological analysis were performed. RESULTS: A total of 32 patients were positive for influenza A virus by virus culture and/or RT-PCR; of these 22 were positive both by viral isolation and RT-PCR, 2 only by virus culture and 8 only by RT-PCR. The novel subtype of influenza A(H1N1)pdm09 was present in 93.4% of the isolates. Phylogenetic analysis of the HA and NA gene sequences showed identities higher than 99.50% in both genes. They were also similar to reference isolates in HA sequences (>99% identity) and in NA sequences (>98.50% identity). Amino acid sequences predicted for the HA gene were highly identical to reference strains. The NA amino acid substitutions identified did not include the oseltamivir-resistant H275Y substitution. CONCLUSION: viral isolation and RT-PCR together were useful for diagnosis of the influenza A(H1N1)pdm09 virus. Variations in HA and NA sequences are similar to those identified in worldwide reference isolates and no drug resistance was found.


Subject(s)
Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/epidemiology , Influenza, Human/virology , Pandemics , Adolescent , Adult , Child , Child, Preschool , Cluster Analysis , Female , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Humans , Male , Molecular Sequence Data , Nasopharynx/virology , Neuraminidase/genetics , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Vietnam , Viral Proteins/genetics , Virus Cultivation , Young Adult
18.
Food Microbiol ; 32(2): 265-73, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22986189

ABSTRACT

Staphylococcal enterotoxins (SEs) produced by Staphylococcus spp. are superantigens responsible for food-poisoning and are associated to mobile genetic elements such as Staphylococcus aureus pathogenicity islands (SaPI). The presence of 13 enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sel, sek, seq, and tst) was tested in 15 S. aureus and 24 coagulase-negative Staphylococcus (CNS) multi-resistant strains isolated from ovine milk in Sardinia. All CNS isolates were enterotoxin-negative, whereas co-presence of sec, sel and tst was observed in most of the S. aureus strains. One isolate of S. aureus was characterized by tst alone. A multiplex PCR assay aimed at discriminating between the integrase genes of pathogenicity islands SaPI2, SaPIbov1, and SaPIMW2 was developed. We demonstrated that strains harboring sec, sel and tst were associated with SaPIbov1, whereas the strain positive for tst was associated with SaPI2. Borderline oxacillin resistant S. aureus strains were also detected. RAPD analysis of the Staphylococcus strains showed that clonal relationships were correlated with pathogenic profiles.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Enterotoxins/metabolism , Milk/microbiology , Oxacillin/pharmacology , Staphylococcus/drug effects , Staphylococcus/isolation & purification , Animals , Food Contamination/analysis , Molecular Sequence Data , Phylogeny , Sheep , Staphylococcus/classification , Staphylococcus/genetics
20.
J Infect Dev Ctries ; 5(6): 437-40, 2011 Jul 04.
Article in English | MEDLINE | ID: mdl-21727641

ABSTRACT

At the beginning of May an outbreak of bloody diarrhoea and haemolytic uraemic syndrome (HUS) began in Germany. During the succeeding months following the initial outbreak in Germany, thousands of infections occurred resulting in 877 cases of haemolytic uraemic syndrome (HUS) with 32 deaths and 3,043 cases of enterohaemorrhagic Escherichia coli (EHEC) with 16 deaths.


Subject(s)
Disease Outbreaks , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Hemolytic-Uremic Syndrome/epidemiology , Hemolytic-Uremic Syndrome/microbiology , Shiga-Toxigenic Escherichia coli/isolation & purification , Adult , Female , France/epidemiology , Genotype , Germany/epidemiology , Humans , Male , Serotyping , Shiga-Toxigenic Escherichia coli/classification , Shiga-Toxigenic Escherichia coli/genetics
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