Aspilia africana (Pers.) C.D. Adams and Manihot esculenta Crantz Exhibit Antibacterial Activity against Resistant Salmonella typhi Strains

Typhoid fever, caused by Salmonella typhi, has plagued underdeveloped countries for many years. Recently, there has been a surge in S. typhi strains identified to be multidrug-resistant in endemic areas. Aspilia africana and Manihot esculenta have been reported to exhibit activity against S. typhi; however, this study aimed to investigate the effect of A. africana and M. esculenta against resistance strains of S. typhi. The leaves of the plants were extracted using distilled water (hot (AQH) and cold (AQC)), methanol (MET), ethyl acetate, and petroleum ether. The extracts were screened in vitro for anti-Salmonella effects against fourteen S. typhi isolates (five multidrug-resistant (MDRST), five ciprofloxacin-resistant (CRST), three nalidixic acid-resistant (NARST), and one sensitive isolate (SS)) using agar well diffusion and microbroth dilution methods. Phytochemical screening showed the presence of tannins, saponins, glycosides, and flavonoids in all polar solvent extracts. Alkaloids were found in all extracts, while triterpenoids were present in all except the aqueous extracts. The AQC of A. africana had the best inhibitory effect on the MDRST and NARST with diameter zones of inhibitions (DZOIs) of 40.0 ± 2.08 mm and 34.0 ± 3.22 mm, respectively. Methanol extract of A. africana had the best inhibitory effect on CRST and SS with DZOIs of 34.0 ± 2.08 and 43.0 ± 3.06 mm, respectively. The AQC and AQH of A. africana and AQH of M. esculenta produced the best MICs and MBCs of 2.5 and 5.0 mg/mL against the MDRST. There was no significant difference in ZOIs of the different solvent extracts against test organisms at p < 0.05. Gas chromatography-mass spectrometry analysis of the extracts showed compounds such as n-hexadecanoic acid, 9,12,15-octadecatrienoic acid (9.55%), and 2H-benzo[F]oxireno[2,3-E]benzofuran-8(9H)-one in the A. Africana extracts and D-mannose, 3-nitrophenyl, methanol acetate (ester), and 9-octadecenamide in the M. esculenta extracts. The leaves of M. esculenta and A. Africana are effective against multidrug-resistant Salmonella isolates.


Introduction
Typhoid fever is a disease that afects people all over the world, although it is most common in places with inadequate sanitation.According to experts, it is one of the most underreported diseases in the developing world.For instance, in Ghana, reported cases of typhoid fever show a disturbing trend and a major public health concern.
Typhoid fever was one of the top twenty causes of outpatient morbidity and 1.2, 1.7, and 1.3% of hospital admissions in 2017, 2016, and 2015, with 365,148, 384,704, and 337,120 cases, respectively [1], in Ghana.
In recent years, there has been a surge in the number of S. typhi resistance strains, especially in endemic areas [2].Te development of multidrug-resistant (MDR) S. typhi strains has worsened the condition leading to high morbidity and mortality rates in most developing countries due to the increased inefectiveness of antibiotics indicated for treating S. typhi infection [3].Hence, there is a need to search for and develop new drugs from natural products to salvage the menace.Natural products such as medicinal plants are still widely used in most developing countries as a reliable source of traditional medicine due to the belief that they are safe and efcacious [4].However, most of these plants have not been scientifcally evaluated to give credence to their folkloric use in Ghana.
Aspilia africana is an indigenous plant used by traditional medicine practitioners in Africa to cure certain illnesses [5].It is known as "nfofo" in Akan, "organgila" in Ibo, "tazalian" in Hausa, "yungung" in Yoruba, and "Makayi" in Luganda (Uganda) [6].It has many traditional uses for its leaves and fowers but the most famous is its use to halt bleeding and accelerate healing of wounds.As a result of its capacity to halt bleeding from recent wounds, it is known as the "haemorrhage plant" [3].It contains biologically active substances that are antiviral, fungicidal, and antibacterial [3].Flavonoids, saponins, tannins, alkaloids, D-, α-pinene, carene, phytol, linolenic acid, β-caryophyllene, and germacrene have been reported to confer anti-infammatory, antimicrobial, and antioxidant activities on A. africana [7].Some studies have been carried out on the antimicrobial activity of A. africana.For instance, the antibacterial activity of A. africana against some clinical isolates of Salmonella typhi has been reported [8].Anibijuwon et al. [9] and Halimat et al. [10] also reported that A. africana exhibits activity against other pathogenic microorganisms.
Manihot esculenta, commonly called cassava, is a tuberous woody shrub of the Euphorbiaceae (spurge) family.Cassava is a perennial woody shrub native to South America and also cultivated in tropical and subtropical zones of the world.It is one of the most vital industrial food crops in the world [3].Cassava tube is utilized as a staple meal by the general public, but the leaves are used to combat and treat a variety of ailments, including rheumatism, gout, diarrhoea, fever, headache, night blindness, intestinal worms, and beriberi [11].In addition to treating skin rashes and fevers, the leaves are also used to cure ringworm, tumours, conjunctivitis, and abscesses.Fresh rhizomes and leaf sap latex are used for eye ulcers and rheumatism, respectively [12,13].Studies indicate that cassava leaf paste contains phytochemicals such as favonoids, tannins, saponins, sitosterol, and stigmasterol, which contribute to its antioxidant, antimicrobial, and anti-infammatory properties [14].Te ethanol extract of M. esculenta has been reported to exhibit activity against Escherichia coli and Salmonella spp. on contaminated meat [15].Mustarichie et al. [16] reported on the activity of M. esculenta leaves against clinical isolates of Staphylococcus epidermidis and Propionibacterium acnes.Te antibacterial activity of cassava M. esculenta leaf extract against Escherichia coli has been reported [17].
Plants have been used for the management of diverse kinds of man's health conditions all over the world from time immemorial.In Ghana, medicinal plants are widely used to treat typhoid fever in both rural and urban settings [18].Extracts from the leaves, barks, seeds, and fruits of plants including A. africana and M. esculenta are used in the preparation of syrups and infusions in traditional medicine for the treatment of ailments such as typhoid fever.Information about the use of these plants in the Ghanaian Traditional practice was complemented with interviews with some local people who always use them to treat typhoid fever [19,20].Some of these medicinal plants have been screened for their activity against typed strains of S. typhi.However, most of these plants have not been screened for their anti-Salmonella activity against resistant strains which are now responsible for most of the typhoid infections reported in hospitals.Tis study, therefore, screened diferent solvent extracts of A. africana and M. esculenta against drugresistant strains of S. typhi and gave credence to the continuous use of these plants in folkloric medicine for treating typhoid fever.

Materials and Methods
Te following is a schematic representation of the methods used in assessing the anti-Salmonella activity of leaves of Aspilia africana and Manihot esculenta against selected drug-resistant strains of S. typhi.Te fresh leaves of A. africana and M. esculenta were washed under running tap water to remove debris and made to drain before air drying under shade for two weeks.Te dried plant materials were ground mechanically with a mortar and pestle into smaller particles and ground into fne particles using a blender.Aqueous (hot and cold), methanol, ethyl acetate, and petroleum ether extracts were prepared by suspending 200 g each of fnely ground leaves in 1000 mL of the respective solvents.Te solutions in the fasks were corked with cotton wools, covered in aluminium foils, and left at room temperature for 3 days with intermittent shaking.Te resulting solutions were fltered using Whatman no. 1 flter paper and the fltrates were kept in a rotary evaporator at 50 °C for complete evaporation of the solvents.Te extracts were then stored in a refrigerator at 4 °C.With the hot water extraction, 200 g of the ground leaves were suspended in 1 litre of sterile water and heated on a burner at 100 °C for 45 minutes.Te resulting solution was allowed to cool and fltered using Whatman no. 1 flter paper and the fltrate was lyophilized.

Test Microorganisms.
Microorganisms used for this study were obtained from the Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR) in welllabelled sterile nutrient broths.Tey included fve multidrug-resistant (MDRST) (G10163, G10209, G10325, G10573, and G10194), three nalidixic acid-resistant (NARST) (G20014, G10037, and G20157), fve ciprofoxacin-resistant (CRST) (G10628, G20247, G11082, G10692, and G10713), and one sensitive strain (SS) S. typhi.Tey were stored in the refrigerator at 4 °C.Te S. typhi strains were streaked on bismuth sulphite agar (BSA) to determine their characteristic appearance (observance of rabbit eye colonies with black metallic sheen).Gram stain and microscopy were used to ascertain whether the organisms were Gram-negative or positive bacteria.Further confrmatory tests were carried out on well-separated colonies grown on BSA using the sulfde indole motility (SIM), catalase, citrate utilization, methyl red-Voges Proskauer (MR-VP), and triple sugar iron agar (TSI) tests.Pure isolates of each organism were inoculated into 10 mL of sterile water and compared to 0.5 M McFarland standard to standardize the approximate number of organisms by comparing their turbidity.Before each experiment, a 24-hour broth culture of the S. typhi (1 * 10 6 CFU/mL) was prepared.

Determination of the Susceptibility of Organisms to
Extracts.Te agar well difusion method described by Boakye et al. [21] was used to determine the susceptibility of the test organisms to the extracts.In this method, the crude extracts were prepared in various concentrations of 100, 30, and 10 mg/mL.Ciprofoxacin (10 µg/mL) was used as a positive control.Te inoculum size of 1.0 × 10 6 CFU/mL of the test organisms was used in all antibacterial determinations.Sterile cotton swabs were used to evenly streak 1 mL of each organism onto their respective Muller-Hinton agar plates.An 8 mm cork-borer was famed and used to aseptically create 4 wells equidistant from each other in each agar plate.A volume of 150 µL of each concentration of the various extracts and ciprofoxacin were aseptically flled into their, respectively, labelled wells using a micropipette.Te plates were left at room temperature for a difusion time of 45 minutes before incubating them at 37 °C for 24 hours.Te plates were observed after the incubation period for clear zones and these were measured with a ruler as the zones of growth inhibition.

Determination of the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of the Extracts.
Te minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts were determined using the microbroth dilution method by Boakye et al. [21].A 96-well microtitre plate was used, and 100 µL of double-strength nutrient broth was added to each well.A stock of 200 mg/mL of each extract was prepared and calculated volumes of the stock solution needed to produce the required concentrations (80, 40, 20, 10, 5, and 2.5 mg/mL) in each well were added.Calculated volumes of sterile water and 20 µL (1 * 10 6 CFU/mL) of the inoculum were added to the appropriate wells to produce the needed concentrations.Ciprofoxacin was used as positive control and prepared in 10, 3, and 1 µg/mL.Te plates were incubated at 37 °C for 24 hours.After incubation, 20 µL of 1.25 mg/mL MTT was added to each well and incubated at 37 °C for 30 minutes to check for growth.A purple colour change indicated the growth of organisms and pale to yellow showed the absence or no growth of organisms.Te least concentration that inhibited growth (exhibited no change of colour from pale yellow to purple) was recorded as the MIC.For the MBC determination, a loopful of cultures were taken from the wells that showed inhibitory activity and subcultured in sterile nutrient broths and incubated at 37 °C for 48 hours followed by the addition of 1.25 mg/mL MTT to each well.Te wells which contained the least concentrations that exhibited no growth after the incubation period were considered as the MBC.Te experiments were carried out in triplicate.

Determination of Phytochemical Constituents.
Te plant extracts were screened for the presence of tannins, saponins, favonoids, glycosides, alkaloids, triterpenoids, and steroids according to the method described by Evans [22] and Gul et al. [23].

Fourier-Transformed Infrared Spectrometry of the
Extracts.Tis was performed to determine the functional groups for the identifcation of compounds in the plants.One milligram of each extract was mounted directly on the KBr disc of the PerkinElmer 200 UATR (FTIR) Scientifca spectrophotometer.It was then scanned through IR regions between the ranges of 400 and 4000 cm − 1 at a resolution of 4 cm − 1 [24].

Gas Chromatography-Mass Spectrometry Analysis of the
Extracts.An amount of 1 mg of each extract was analyzed by GC-MS.Te analysis was carried out using a PerkinElmer Clarus 580 and (Clarus SQ 8 S) GC/MS with an Elite 5 MS column that has a dimension of 30 × 0.25 m ID × 0.25 m DF and is 5% diphenyl/95% dimethylpolysiloxane. Te injector and ion source were kept at respective temperatures of 250 °C and 150 °C.With an ionization energy of 70 electronvolts (Ev) and helium gas that was 99.99% pure acting as the carrier gas, the GC-MS detection was run in electron impact mode with a constant fow rate of 1 mL/min.Te bioactive fractions' mass spectra were read at 70 Ev, scanned in 0.5 seconds, and then fragmented by their mass-to-charge ratio from 45 to 450 Da.A TurboMass detector was used to fnd the separated ions, and TurboMass version 6.1.0software was used to record the chromatogram by amplifying the signals from the spectra.To initialize the system, the solvent was started at 0 minutes and delayed for 2 minutes before being run for 47 minutes on the GC-MS.Te determined bioactive fractions' mass spectra were analyzed, and they were contrasted with the GC-MS spectrum database maintained by the National Institute of Standards and Technology (NIST).

Preliminary Phytochemical Screening of Plant Extracts.
Te tests were carried out to give an idea about the secondary metabolites present in the plants.Phytochemical screening showed the presence of saponins, glycosides, tannins, and favonoids in all the polar solvent extracts but not the nonpolar.Alkaloids were present in all extracts, while triterpenoids were present in all except the aqueous extracts.Sterols were absent in all the extracts (Table 2).

Fourier-Transform Infrared Spectrometry (FTIR) Analysis.
Te FTIR analysis of the various plant extracts revealed peaks with their respective functional groups.A. africana had peaks ranging between 970.37 and 3388.46 cm − 1 with S�O bending, C-N stretching, O-H bending, C�C bending, Csp3-H stretching, O-H stretch, C-O stretching, C-H stretching, N-H stretching, and C-H bending as predictable functional peaks present (Table 3).M. esculenta had peaks ranging between 972.89 and 3234.28 cm − 1 with CO-O-CO/S�O stretch, S�O/C-O/C-N stretch, C�C stretch, Csp3-H stretch, O-H stretch, C-O stretch, O-H bending, C�O stretch, C�C bending, and C-H bending as predictable functional peaks present (Table 4).
Te petroleum ether extract of A. africana showed no activity against any of the CRST strains at all test concentrations (Figure 1, A2).

MIC of Extracts of A. africana and M. esculenta against
Test Organisms.Te hot aqueous extract of A. africana showed the best MIC (2.5 mg/mL) against the MDRST strains, G10163, G10209, and G10325.Te cold aqueous extract of A. africana also had the best MIC (2.5 mg/mL) against the MDRST strain, G10209.Te methanol and hot aqueous extracts of A. africana showed the best MICs of 5 mg/mL each against the sensitive strain (SS).
Te cold aqueous extract of A. africana showed the best MIC of 5 mg/mL each against the CRST strains, G10628, G20247, and G11082.Te hot aqueous extract of A. africana also had the best MIC (5 mg/mL) against the CRST strains, G10628 and G20247.Te methanol and hot aqueous extracts of A. africana showed the best MICs of 5 mg/mL each against the CRST strain, G10713, and the sensitive strain (SS).
Te cold aqueous extract of A. africana showed the best MIC of 5 mg/mL each against the NARST strains, G10037 and G20157.Te methanol and hot aqueous extracts of A. africana also had the best MIC (5 mg/mL) against the NARST strain, G20014, and the sensitive strain (SS) (Table 5).
Te cold aqueous extract of M. esculenta showed the best MIC (2.5 mg/mL) against the MDRST strains, G10163 and G10209.Te hot aqueous extract of M. esculenta showed the best MIC of 5 mg/mL against the sensitive strain (SS).
Te methanol and cold aqueous extract of M. esculenta showed the best MICs (5 mg/mL each) against the CRST strain, G20247.Only the methanol extract of M. esculenta had the best activity against the sensitive strain (SS) with a MIC of 5 mg/mL.
Only the methanol extract of M. esculenta had the best MIC (5 mg/mL) against the NARST strain, G20157 (Table 5).

MBC of Extracts of A. africana and M. esculenta against
Test Organisms.Te hot aqueous extract of A. africana showed the best MBC (5 mg/mL each) against the MDRST strains, G10163, G10209, and G10325.Te cold aqueous extract of A. africana also had the best MBC (5 mg/mL) against the G10209 strain.
Te cold aqueous extract of A. africana showed the best MBC of 10 mg/mL each against the CRST strains, G10628, G20247, and G11082.Te hot aqueous extract of A. africana also had the best MBC (10 mg/mL each) against the CRST strains, G10628, G20247, and G10713.Both methanol and hot aqueous extracts of A. africana showed the best MBCs of 10 mg/mL each against the sensitive strain (SS).
Te cold aqueous extract of A. africana showed the best MBC (10 mg/mL each) against the NARST strains, G10037 and G20157.Te methanol and hot aqueous extracts of
Te hot aqueous extract of M. esculenta showed the best MBC (5 mg/mL each) against the MDRST strains, G10163 and G10209.
Te methanol and cold aqueous extract of M. esculenta showed the best MBC of 10 mg/mL each against the CRST strain, G20247.Only the methanol extract of M. esculenta showed the best MBC of 10 mg/mL against the sensitive strain (SS).
Only the cold aqueous extract of M. esculenta had the best MBC (10 mg/mL) against the NARST strain, G20157 (Table 6).

Gas Chromatography-Mass Spectrometry Analysis (GC-MS) of A. africana and M. esculenta. GC-MS was used to
separate, quantify, and analyze volatile chemicals that may be responsible for the therapeutic efect of the plant extracts.

Discussion
Medicinal plants have been used in the past and are still utilized for their therapeutic benefts.Aspilia africana and Manihot esculenta are plants that are traditionally used in Ghana for the management and treatment of typhoid infections.Tis study sought to assess the efects of extracts of A. africana and M. esculenta on resistant strains of Salmonella typhi.Te solvents used in the extraction process were aqueous (cold and hot), methanol, ethyl acetate, and petroleum ether.Tese solvents were used based on their eluotropic series to extract a wide range of bioactive compounds.Many medicinal plant parts are boiled locally before they are used to treat various ailments, while others are left in cold water and alcohol, respectively, for days before they are taken.Research has shown that a combination of ethanol and water gives a better extraction yield of phytochemicals [25].Te extraction of the plants studied showed that the solvents used were able to extract most phytoconstituents but with varying amounts.
All solvent extracts of A. africana and M. esculenta had diferent yields.Tis confrms the report that diferences in the polarity of solvents afect the yield of extracts [26].In a study conducted by Oko and Agiang [27], the percentage yield after extracting the leaves of A. africana with water at room temperature was calculated to be 10.2%, which is lower than the yield obtained in this study (25.42%).Tis could be due to diferences in methods of preparation and geographical locations of the plant samples [28].N/I, no inhibition; P ET, petroleum ether extract; E TA , ethyl acetate extract; M ET , methanol extract; A QC, cold aqueous; A QH , hot aqueous; C IP , ciprofoxacin; SS, sensitive strain.
10 Scientifca   12 Scientifca On an individual plant basis, the hot aqueous extracts of both A. africana and M. esculenta had the highest percentage yields, which may be due to the application of heat that increased the release of the various plant phytoconstituents into the water used for the extraction.From the percentage yield results, it could be inferred that the hot water was found to be the best extraction solvent for both A. africana and M. esculenta, followed by aqueous cold, methanol, and ethyl acetate.
Te antibacterial activity of the various plant extracts was determined against all fourteen organisms using the cupplate agar difusion method.Te various extracts of the leaf of A. africana and M. esculenta had inhibitory efects against the multidrug-resistant, ciprofoxacin-resistant, nalidixic acid-resistant, and the sensitive strain S. typhi (MDRST, CRST, NARST and SS, respectively) at the test concentrations (100, 30, and 10 mg/mL).Te highest respective concentrations of almost all extracts of A. africana and M. esculenta gave the highest zones of inhibition.Tis fnding is in agreement with a study by Oluduro and Omoboye [29], which reported that the antibacterial activities of most plant extracts are concentration-dependent, as the zone of growth inhibition increases with increasing concentration of the extracts.Kambar et al. [30] also reported that the efcacy of most plant extracts is concentration-dependent.
Tere were diferences in the zones of inhibitions (ZOIs) recorded for the polar solvent extracts of both A. africana and M. esculenta.For instance, the cold aqueous extract of A. africana at 100 mg/mL had the highest ZOI (40 ± 2.08 mm), followed by the hot aqueous extract (37 ± 3.51 mm) and the methanol extract (33 ± 2.08 mm) against an MDRST strain (Figure 1, A1).Te hot aqueous extract of M. esculenta had the best ZOIs of 38 ± 2.52 mm, followed by the cold aqueous (35 ± 2.08 mm) and the methanol extract (25 ± 1.53 mm) against the MDRST strain (Figure 2, X1).Te best ZOI against a CRST strain was exhibited by the methanol extract (34 ± 2.08 mm) of A. africana, at 100 mg/mL, followed by the hot aqueous extract (24 ± 2.52 mm) and the cold aqueous extract (22 ± 2.08 mm) (Figure 1, A2).Te hot aqueous extract of M. esculenta had the best ZOIs of 30 ± 1.53 mm, followed by the methanol (29 ± 1.53 mm) and cold aqueous extract (23 ± 1.53 mm) against a CRST strain (Figure 2, X2).
Te best ZOI against a NARST strain was exhibited by the cold aqueous extract (34 ± 3.22 mm) of A. africana, at 100 mg/mL, followed by the methanol (33 ± 2.52 mm) and the hot aqueous extract (28 ± 1.53 mm) (Figure 1, A3).Te hot aqueous extract of M. esculenta had the best ZOIs of 24 ± 1.53 mm, followed by the methanol (23 ± 3.51 mm) and cold aqueous extract (22 ± 2.65 mm) against a NARST strain (Figure 2, X3).Even though there were diferences in the ZOIs recorded for the methanol and the hot and cold aqueous extracts of both A. africana and M. esculenta, there was no signifcant diference in the zones of inhibition of these diferent solvent extracts against the test organisms at p < 0.05.
Te slight diference in activity between the hot and cold aqueous and methanol extracts could be attributed to the diferences in the compounds identifed through GC-MS since the preliminary phytochemical screening revealed similar bioactive constituents in the various plant extracts.Tough the compounds identifed have other pharmacological activities, a few of them have been reported to exhibit antibacterial activity.Lupeol á-amyrin found in the ethyl acetate extract of M. esculenta is reported to exhibit antibacterial activity [31].Reports indicate that D-mannose which was identifed in the cold aqueous extract of M. esculenta can inhibit bacterial adhesion to the urothelium after oral intake [32].Terefore, the anti-Salmonella activity exhibited by the extracts of M. esculenta and A. africana could be attributed to the presence of some of these compounds.
Te M. esculenta cold aqueous extract at 100 mg/mL had the lowest ZOI of 18.0 ± 1.53 mm.However, Adam et al. [33] reported a ZOI of 17 mm and no inhibition with aqueous extract of bulb and peels, respectively.Te fndings of Adam et al. had lower anti-Salmonella activities compared to this current study (18.0 ± 1.53 mm), which can be attributed to the diferences in the plant part used.
Te ethyl acetate extracts of A. africana and M. esculenta had the least zones of inhibitions and better minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, and the petroleum ether extracts of both plants showed no activity against the test organisms, both in the agar well difusion experiments and the broth dilution assay, compared to the aqueous and methanol extracts.Te superior anti-Salmonella activity of the aqueous and methanol extracts justifes the principle observed in herbal practitioners' preference for using local gin as an extraction agent [34], and sometimes water.
Te FTIR analysis of the various plant extracts showed the presence of functional groups such as S�O bending, C-N stretching, O-H bending, C�C bending, O-H stretch, C-O stretching, C-H stretching, N-H stretching, and C-H and C�O stretch (Table 4).Te presence of these functional groups is indicative of compounds such as aldehydes, phenols, favonoids, amines, and ketones, [35], of which favonoids have been reported to exhibit antibacterial activities [36].
Te presence of phytochemical compounds in M. esculenta and A. africana might have contributed to their anti-Salmonella activity since it is known that the active compounds produced by plants inhibit the life process of microbes especially the disease-causing ones [36].For instance, tannins, alkaloids, favonoids, and saponins glycosides have been reported to exhibit antibacterial activity [37].Again, preliminary phytochemical screening showed the presence of saponins, glycosides, tannins and favonoids in all the polar solvent extracts but not the nonpolar, which could also contribute to the better anti-Salmonella activity exhibited by the polar extracts for both M. esculenta and A. africana, most especially the aqueous extracts.

Conclusion
Hot water extracts of A. africana and M. esculenta had the highest percentage yield.Phytochemical screening revealed the presence of tannins, alkaloids, glycosides, saponins, and Scientifca favonoids in the plant extracts.Cold aqueous, hot aqueous, and methanol extracts of both plants had good anti-Salmonella activity, while ethyl acetate extracts had a weak anti-Salmonella activity.Petroleum ether extracts had no inhibitory efect against the test microorganisms.Hot aqueous extracts of M. esculenta and cold and hot aqueous extracts of A. africana had the best bactericidal efect on the MDRST.Te methanol and aqueous (hot and cold) extracts of both A. africana and M. esculenta showed the best bactericidal efect against the SS.Methanol extract of A. africana had the best inhibitory efect against CRST.Aqueous extract of A. africana had the best inhibitory efect on the NARST.FTIR and GC-MS analysis showed the presence of probable compounds, some with reported antibacterial activity.Tese fndings confrm the traditional usage of the plants and provide a scientifc basis for their use in traditional medicines in the treatment of typhoid fever.
QH M ET E TA P ET Cip A QC A QH M ET E TA P ET Cip A QC A QH M ET E TA P ET Cip Solvent extracts (100 mg/mL) (0.01 mg/mL) Solvent extracts (30 mg/mL) (0.01 mg/mL) Solvent extracts (10 mg/mL) (0.01 mg/mL) QH M ET E TA P ET Cip A QC A QH M ET E TA P ET Cip A QC A QH M ET E TA P ET Cip Solvent extracts (100 mg/mL) (0.01 mg/mL) Solvent extracts (30 mg/mL) (0.01 mg/mL) Solvent extracts (10 mg/mL) (0.01 mg/mL)
Te solvents used were selected based on increasing polarity (petroleum ether, ethyl acetate, and methanol).Aqueous extracts (both hot and cold) that are often used traditionally in the management of diseases were also prepared.

Table 2 :
Phytochemical composition of M. esculenta and A. africana extracts.− , phytoconstituent is absent; P ET , petroleum ether extract; E TA , ethyl acetate extract; M ET , methanol extract; A QC , cold aqueous; A QH , hot aqueous.

Table 3 :
IR spectra of functional groups present in various extracts of Aspilia africana.

Table 4 :
IR spectra of functional groups present in various extracts of Manihot esculenta.QH M ET E TA P ET A QC A QH M ET E TA P ET A QC A QH M ET E TA P ET A QC A QH M ET E TA P ET A QC A QH M ET E TA P ET

Table 5 :
MICs of extracts of A. africana and M. esculenta against test organisms.

Table 6 :
MBC of extracts of A. africana and M. esculenta against test organisms.

Table 7 :
Compounds identifed in A. africana by GC-MS analysis.

Table 8 :
Compounds identifed in M. esculenta by GC-MS analysis.