Retrospective study of anaplasmosis in countries of North Africa and the Middle East.

Anaplasmosis is a tick-borne disease caused by bacteria of the genus Anaplasma, which consists of six species affecting livestock and wild animals, and humans, worldwide. Anaplasma marginale and Anaplasma phagocytophilum are the most important species for veterinary and human health. Infections of livestock have a noticeable economic impact due to reduced growth or loss of animals. This study provides information on anaplasmosis in animal populations of countries in North Africa and the Middle East. Relevant national and international scientific publications were evaluated for studies of the epidemiology of anaplasmosis between 1959 and 2019. The serological assay results showed a prevalence of 13.5%-89.7% in cattle in North Africa, and 35%-36% in cattle, 44.7%-94% in small ruminants and 10.83% in camels in Middle Eastern countries. Sample positivity for Anaplasma species by molecular assays revealed a range of 3.5%-69.3% in cattle, 2.5%-95% in small ruminants and 17.7%-88.89% in camels in North African countries and 95% of cattle, 15.5%-66.7% of small ruminants and 28%-95.5% of camels in the Middle East. Polymerase chain reaction (PCR) detection of all six Anaplasma species in North Africa and of Anaplasma ovis and A. phagocytophilum in the Middle East was reported in livestock. This review shows that anaplasmosis is endemic in North Africa and the Middle East and represents a threat not only to the economies of these countries but also to public health. Thus, surveillance and implementation of control measures are important tools to optimise future strategic control programmes and prevent spread to neighbouring countries.

L'anaplasmose est une maladie transmise par les tiques et causée par une bactérie du genre Anaplasma, qui recouvre six espèces affectant le bétail et la faune sauvage ainsi que les humains dans le monde entier. Anaplasma marginale et Anaplasma phagocytophilum sont les espèces les plus importantes en médecine vétérinaire et humaine. Chez le bétail cette maladie a des répercussions économiques significatives en raison du ralentissement de la croissance ou des pertes d'animaux qu'elle induit. Les auteurs présentent les informations qu'ils ont réunies sur l'anaplasmose dans les populations animales de plusieurs pays d'Afrique du Nord et du Moyen-Orient. Les données analysées proviennent des publications scientifiques internationales et nationales consacrées à l'épidémiologie de l'anaplasmose entre 1959 et 2019. Le taux de prévalence tel qu'il ressort des enquêtes sérologiques consultées fluctuait chez les bovins d'Afrique du Nord de 13,5 % à 89,7 %, tandis que dans les pays du Moyen-Orient, la prévalence était de 35 %-36 % chez les bovins, variait de 44,7 % à 94 % chez les petits ruminants et s'élevait à 10,83 % chez les camélidés. Le pourcentage d'échantillons positifs pour Anaplasma spp. parmi ceux soumis à des tests moléculaires dans les pays d'Afrique du Nord variait de 3,5 % à 69,3 % chez les bovins, de 2,5 % à 95 % chez les petits ruminants et de 17,7 % à 88,89 % chez les camélidés, tandis qu'au Moyen-Orient il était de 95 % chez les bovins et variait de 15,5 % à 66,7 % chez les petits ruminants et de 28 % à 95,5 % chez les camélidés. Chez les animaux d'élevage, en recourant à l'amplification en chaîne par polymérase (PCR), les six espèces d'Anaplasma ont été détectées en Afrique du Nord tandis qu'au Moyen-Orient seules Anaplasma ovis et A. phagocytophilum ont été détectées. Cette revue de la littérature montre que l'anaplasmose est présente à l'état endémique en Afrique du Nord et au Moyen-Orient et qu'elle représente une menace non seulement pour les économies de ces pays mais aussi pour la santé publique. Les auteurs en concluent que la surveillance et la mise en place de mesures de contrôle constituent des outils essentiels pour optimiser les futurs programmes stratégiques de lutte contre la maladie et prévenir sa propagation vers les pays voisins.

La anaplasmosis es una enfermedad transmitida por garrapatas cuyo agente etiológico son las bacterias del género Anaplasma, formado por seis especies que afectan al ganado y los animales silvestres, así como al ser humano, en todo el mundo. Anaplasma marginale y Anaplasma phagocytophilum son las especies más importantes desde el punto de vista de la veterinaria y la medicina. Las infecciones del ganado tienen notorios efectos económicos porque lastran el crecimiento de los animales o causan la pérdida de ejemplares. Los autores describen un estudio que aporta información sobre la anaplasmosis en las poblaciones animales de países norteafricanos y de Oriente Medio. Para llevar a cabo el estudio se examinaron publicaciones científicas nacionales e internacionales en busca de investigaciones que arrojaran luz sobre la epidemiología de la anaplasmosis entre 1959 y 2019. Los resultados de los ensayos serológicos descritos en la bibliografía revelaban una prevalencia del 13,5% al 89,7% en el ganado bovino norteafricano y, en cuanto a los países de Oriente Medio, del 35% al 36% en bovinos, del 44,7% al 94% en pequeños rumiantes y del 10,83% en camellos. El análisis de las muestras con técnicas moleculares deparaba los siguientes porcentajes de positividad para especies de Anaplasma: en los países norteafricanos, un intervalo del 3,5% al 69,3% en bovinos, del 2,5% al 95% en pequeños rumiantes y del 17,7% al 88,89% en camellos; en Oriente Medio, un 95% en bovinos, del 15,5% al 66,7% en pequeños rumiantes y del 28% al 95,5% en camellos. En el ganado bovino se describía la detección por reacción en cadena de la polimerasa (PCR) de las seis especies de Anaplasma en África del Norte y de Anaplasma ovis y A. phagocytophilum en Oriente Medio. Este estudio pone de manifiesto que la anaplasmosis es endémica en África del Norte y Oriente Medio y representa una amenaza no solo para la economía de estos países, sino también para la salud pública. La vigilancia y la aplicación de medidas de control son por lo tanto herramientas importantes para optimizar futuros programas estratégicos de lucha y prevenir la extensión de la enfermedad a países vecinos.

Efficacy of silver nanoparticles against multidrug resistant clinical Staphylococcus aureus isolates from Nigeria.

Multidrug resistant (MDR) S. aureus infections continue to account for excess mortality in hospital and community settings and constitute a rising global health problem. However, data on the efficacy and mechanism of actions of alternative solutions like silver nanoparticles in developing countries are lacking. This study investigated anti-staphylococcal activity of silver nanoparticles (AgNP) against local strains from Nigeria. A total 119 clinical isolates of S. aureus from five Nigerian laboratories categorized as MRSA (n = 52) and MSSA (n = 67) by PCR were studied. The MIC of AgNP produced by chemical reduction method and characterized by surface plasmon resonance absorbance and size equivalence by scanning electron microscopy was determined by microbroth dilution method. Its effect on protease activity and plasmids were also investigated. Baseline characteristics of the isolates revealed MDR phenotype of the isolates, carriage of diverse plasmids (15-32 kb) among the MDR MSSA, and mean extracellular protease activity of 24.8-55.7 U/mL. The chemically synthesized AgNP had a peak absorbance at 400 nm with a size equivalence of 4.58 nm. The MICs of AgNP against the isolates were 4.7 µg/mL and 4.9 µg/mL, respectively, for MRSA and MSSA (P > 0.05). The bactericidal effect of AgNP at 2.5-5 µg/mL on the MSSA and MRSA isolates was observed at 2.7-5.5 h post exposure in vitro. Further analysis revealed plasmid eviction in the MDR MSSA isolates exposed to 5 µg/mL AgNP and dose-dependent reduction in extracellular protease activity by 84.6-93.1%. Hemolysis of human erythrocytes by AgNP was not observed at the MIC range. Conclusion: This study revealed safety and efficacy of AgNP against clinical MDR S. aureus isolates from Nigeria, using plasmid eviction and protease inhibition as mechanisms of action.

Prevalence of multiple drug resistance and screening of enterotoxin (stn) gene in Salmonella enterica serovars from water sources in Lagos, Nigeria.

OBJECTIVE: To determine the prevalence, antibiotic resistance and carriage of enterotoxin (stn) gene among strains of Salmonella isolated from water sources in Lagos. STUDY DESIGN: A total of 200 samples (60 well water, 60 pipe-borne water and 80 different brands of sachet water) were collected at random from various locations in Lagos. METHODS: The samples were evaluated bacteriologically using standard methods. The identified isolates were subjected to antimicrobial susceptibility tests and were further screened for the presence of stn gene using standard procedures. RESULTS: Thirty-seven of the samples analysed were positive for Salmonella isolates. Seven serotypes were found -Salmonella typhi (n = 3, 8.1%), Salmonella typhimurium (n = 8, 21.6%), Salmonella choleraesuis (n = 5, 13.5%), Salmonella enteritidis (n = 9, 24.3%), Salmonella paratyphi (n = 8, 21.6%) and Salmonella arizonae (n = 4, 10.8%) - with at least one serotype present in all water sources. Over 60% of Salmonella isolates carried stn gene and the risk was higher in pipe-borne water. There was no relationship (P > 0.05) between enterotoxin-producing gene and antibiotic resistance in Salmonella isolates. Thirteen resistance patterns were exhibited by the isolates, with Str. Amp.Tet.Chl.Amo.Gen, Str. Amp.Tet.Amo.Chl.Amo.Nal.Nit, Str.Tet and Str. Amp.Tet.Chl.Amo being the most notable resistance patterns observed. Isolates that carried stn gene developed resistance to more antibiotics. Although reduced susceptibility to ciproflocacin was observed in two strains, none of the isolates developed resistance to ofloxacin. CONCLUSION: Emerging multidrug-resistant Salmonella serotypes with stn gene were found in the water samples, which may pose a threat to public health. Constant monitoring of pipe leakages, the quality of various wells and the quality of sachet water is advocated to avoid possible future outbreaks of salmonellosis due to consumption of contaminated water.

Occurrence of extended-spectrum and AmpC ß-lactamases in multiple drug resistant Salmonella isolates from clinical samples in Lagos, Nigeria.

PURPOSE: Salmonella spp. are important foodborne pathogens exhibiting increasing resistance to antimicrobial drugs. Resistance to broad-spectrum ß-lactams, mediated by extended-spectrum ß-lactamase (ESBL) and AmpC ß-lactamase enzymes is fast spreading and has had negative impacts on the clinical outcomes, particularly on third-generation cephalosporins. This study investigated the carriage of AmpC gene among multidrug-resistant Salmonella spp. from Lagos, Nigeria. METHODS: Forty Salmonella spp. from clinical samples (S. typhi = 13; S. typhimurium = 10; S. enteritidis = 8; S. choleraesuis = 5; S. paratyphi = 4) were subjected to in vitro susceptibility test by disk diffusion methods. Isolates that were resistant to cefoxitin and third-generation cephalosporins were screened for ESBL (Double Disk Synergy Test Method) and AmpC enzyme (AmpC disk test) production. Detection of AmpC fox gene was carried out by polymerase chain reaction. RESULTS: Thirty-two (80%) of the Salmonella isolates were cefoxitin resistant. Plasmid-mediated AmpC ß-lactamase and ESBL enzymes were recorded in 10/40 (25%) and 16/40 (40%) of the Salmonella isolates, respectively. Specifically, 16/40 (40%) of the Salmonella isolates possessed 380 bp AmpC fox gene, with the highest occurrence found in S. typhi strains (43.8%) followed by S. typhimurium (25%). There was no AmpC fox gene detected in S. paratyphi strains. Interestingly, coproduction of enzymes occurred in some of the isolates, raising fears of resistance to a multitude of antibiotics in the treatment of bacterial infections. CONCLUSION: Emergence of AmpC ß-lactamase-producing Salmonella isolates in our environment was recorded for the first time, raising concern on increased antibiotic resistance among strains of Salmonella serovars in Lagos. Further genotypic study of the isolates could answer the questions on strain sources, clonal relatedness, and mechanism of spread.

Prevalence of multi-drug resistant Salmonella typhi among clinically diagnosed typhoid fever patients in Lagos, Nigeria.

A total of 635 clinically diagnosed typhoid fever patients were bled from three different health institutions in the metropolis of Lagos, Nigeria over a period of 15 months, May 1997 to July 1998. Out of the total blood cultured, 101 (15.9%) isolates of Salmonella species were isolated of which 68 (67.3%) were S. typhi, 17 (16.8%) and 16 (15.8%) were S. paratyphi A. and S. arizonae respectively. The overall isolation rate of S. typhi among patients is 10.7%, with most isolates 45.9% found among the severely-ill young adults, age group 16-30 years. All isolates were subjected to anti-microbial susceptibility testing using 12 different antibiotics: chloramphenicol, ampicillin, cotrimoxazole, gentamicin, colistin sulfate, nalidixic acid, nitrofurantoin, cefotaxime, tetracycline, streptomycin, ofloxacin and ciprofloxacin. All the S. typhi and S. paratyphi A isolates showed resistance to two or more of the 10 of 12 antibiotics tested particularly the 3-first-line antibiotics commonly used (chloramphenicol, ampicillin and cotrimoxazole) in the treatment of typhoid fever in Nigeria. No isolate showed resistance to ofloxacin and ciprofloxacin, however, nalidixic acid and gentamicin showed a moderate and appreciable inhibition to most of our isolates.

Escherichia coli in patients with acute gastroenteritis in Lagos, Nigeria.

Over a period of 12 months, a total of 852 stool samples from patients (both children and adults) with acute diarrhoeal diseases attending some public and government recognised health institutions in Lagos metropolis were screened for diarrhoeagenic bacterial agents. One hundred and eighty two bacterial isolates were found out of which 83 (45.6%) were Escherichia coli, 38 (20.9%) Shigella spp, 31 (17%) Salmonella spp, 16 (8.8%) Klebsiella spp, eight (4.4%) Aeromonas spp, while there were only six (3.3%) isolates for Plesiomonas spp. Of the 83 isolates for E. coli group, 49 (59%) were enteropathogenic (EPEC), 17 (20.5%) enterotoxigenic (ETEC), 10 (12.1%) enteroinvasive (EIEC) and seven (8.4%) enterohaemorrhagic (EHEC). The EPEC strains particularly serotype 055, were mostly encountered in children aged over five years. On the other hand, EIEC and ETEC strains were found mainly in adults while EHEC O157: H7 strains occurred in all the age groups studied. This study further stresses the important role of EIEC and ETEC in acute diarrhoeal diseases and the possible implication of EHEC in acute gastroenteritis, especially in children in Lagos, Nigeria.

Multidrug resistance in Salmonella enterica serovar typhi isolated from patients with typhoid fever complications in Lagos, Nigeria.

OBJECTIVE: The aim of this study was to determine the prevalence of Salmonella enterica serovar typhi in patients with pyrexia of unknown origin (PUO), and antimicrobial resistance in strains isolated from patients with S. typhi in Lagos, Nigeria. STUDY DESIGN: In total, 103 patients were included in this study, subdivided into two categories. Category A comprised 74 patients presenting with PUO, and Category B comprised 29 patients harbouring S. typhi who did not respond to initial treatment. METHODS: Blood samples were cultured for bacterial isolates and identified by standard procedures. Susceptibility testing was performed according to the National Committee for Clinical Laboratory Standards. Plasmid DNA extraction was performed using the alkaline lysis method with Escherichia coli v517 used as the standard. Conjugation and transformation experiments were performed using standard methods. For the latter, E. coli K12 HB 101 (ara-14, galK2, hsd 520, lacyl, leu, mtl-1, Pro A2, rec A13, rps L20, sup E44, thii xyl-5) was used as the recipient and plasmid PBR 322 was used as the positive control. RESULTS: The prevalence of S. typhi in PUO was 16.2% (12/74). In all, 25 of 41 (61.0%) cases were multidrug resistant (MDR) with phenotypic-resistant patterns: ACoCT, ACTCeS, ACTCoCe and ACTS were commonly encountered among the strains. Interestingly, four of the strains harbouring similar plasmid DNA were isolated from patients with hepatosplenomegaly, and a strain harbouring a large transferable plasmid of 81.2MDa was isolated from a psychosis patient. CONCLUSIONS: Our study confirmed the circulation of MDR S. typhi in Lagos, Nigeria. Periodic review of antibiotics used in hospitals is essential as the efficacies of chloramphenicol, ampicillin and cotrimoxazole are now doubtful. Ciprofloxacin and ofloxacin are effective drugs for treatment of typhoid fever, but with current trends of drug abuse in Nigeria, resistance is likely to develop. These results, therefore, provide an early warning signal for the prudent use of fluoroquinolone antimicrobials to preserve their usefulness.

Screening of some medicinal plants used in south-west Nigerian traditional medicine for anti-Salmonella typhi activity.

Ten Nigerian medicinal plants used traditionally for the treatment of several ailments of both microbial and non-microbial origins were tested on multi-drug resistant S. typhi (MDR) strains of which six of them were active. The results revealed that both the aqueous and ethanol extracts of Terminalia avicennioides, Momordica balsamina, Combretum paniculatum and Trema guineensis were effective on the MDR-S. typhi strains with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranging from 9.60 to 14 mcg/ml and 24 to 33 mcg/ml, respectively. Whereas, only the aqueous extracts of Morinda lucida and Ocimum gratissimum were found to be active against this pathogen with MIC and MBC values of 9.60 and 24 mcg/ml for M. lucida, 40 and 55 mcg/ml for O. gratissimum, respectively. There was no statistical significant difference (P > 0.05) between the activity of each plant extract and the decoctions prepared from them. All the six active plants showed positive reactions to alkaloids, tannins, flavonoids and anthraquinones but in variable degrees. All but M. balsamina, indicated the presence of saponin.