Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya
Camels (Camelus dromedarius) are the most valuable livestock species in the arid and semi-arid lands in the Horn of Africa where the majority of the human population adopts a pastoralist lifestyle with extensive animal husbandry. Camels provide an important food source, milk, which is considered...
| Autor principal: | |
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| Formato: | Second cycle, A2E |
| Lenguaje: | sueco Inglés |
| Publicado: |
2021
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/16707/ |
| _version_ | 1855572783688318976 |
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| author | Lejon Flodin, Emelie |
| author_browse | Lejon Flodin, Emelie |
| author_facet | Lejon Flodin, Emelie |
| author_sort | Lejon Flodin, Emelie |
| collection | Epsilon Archive for Student Projects |
| description | Camels (Camelus dromedarius) are the most valuable livestock species in the arid and semi-arid
lands in the Horn of Africa where the majority of the human population adopts a pastoralist lifestyle
with extensive animal husbandry. Camels provide an important food source, milk, which is
considered to be the most important commodity, and a source of income for the pastoralists. The
health of the camel, and especially the udder health, is therefore very important for the pastoralist
communities living in the arid areas in Kenya that do not support other livestock.
Streptococcus agalactiae (SRA) is considered to be a zoonotic bacterium that can cause disease
in both humans and animals but its zoonotic potential is not entirely clarified. It is a highly contagious udder-bound pathogen most known as a cause of mastitis, particularly in cattle, but also in
camels. A few studies have also isolated SRA in apparently healthy camels, suggesting the bacteria
could be a commensal.
Antibiotic resistance (ABR) is a serious health threat to both humans and animals as well as a
threat to food security, global development and economies worldwide. Antibiotic resistance in
bacteria causing disease in camels can potentially be transmitted to people consuming camel
products or handling these animals. The two antibiotic classes that are most frequently used in
livestock production are tetracyclines and β-lactams. Tetracycline resistance has been observed in
SRA isolates derived from camels in Kenya, but little resistance to β-lactams has been found.
The prevalence of resistant and possibly multi-resistant bacteria in camels in Kenya is not known
to a great extent. The aim of this study was to investigate if phenotypic ABR and possibly multiresistance is present in SRA isolates from dairy camels in Laikipia County, Kenya. The overall
objective was to increase the knowledge of ABR among SRA in dairy camels in order to prevent
further resistance development.
In this study, six camel herds were selected for sampling; ranches (n=3), pastoralist (n=1) and
smallholders (n=2). From each herd all lactating dams and their respective calves were sampled. In
total, 179 individuals were sampled; 89 lactating camels and 90 calves. In lactating camels, milk
samples were collected from lactating dams with a California Mastitis Test score of 2 or higher and
swabs were taken from the nasal and vaginal mucosa; in their respective suckling calves from the
nasal, oral and rectal mucosa. Primary identification of SRA in milk and swab samples was
performed by bacterial culturing and confirmed by Matrix assisted laser desorption ionization-time
of flight (MALDI-TOF). Antimicrobial susceptibility testing was performed by broth microdilution
method to determine antimicrobial susceptibility in SRA isolates.
In this study, SRA was isolated from 27% of the sampled individuals. The bacterium was found
at all sampling sites, except for vaginal swabs, in both healthy and CMT-positive lactating dams as
well as in apparently healthy calves, supporting the suggestion that SRA is a commensal and an
opportunistic pathogen in camels. The overall prevalence of tetracycline-resistant SRA isolates was
high (57%) in the six herds, especially in the pastoral and ranch managed systems. No resistance to
penicillin was detected. Tetracycline-resistant SRA isolates were found at all SRA-positive
sampling sites. All SRA isolates from milk samples were resistant to tetracycline. A few camels and
calves were SRA-positive in more than one sampling site and resistance to tetracycline could be
found in one, two or none of these isolates. The results in this study, in combination with earlier
results from Kenya, shows that a shift from the use of tetracycline to penicillin when treating
diseases in camels would be favourable as there is a risk that tetracycline would be ineffective.
Bacteria that already have acquired resistance genes will however continue to spread within and
between herds. Hence, finding a resistant bacterial isolate in a camel does not per se mean that the
bacterium has become resistant due to antibiotic treatment. To avoid further development of resistant
bacteria, prevention of disease is the most important objective. Healthy animals do not require
antibiotic treatment. |
| format | Second cycle, A2E |
| id | RepoSLU16707 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish Inglés |
| publishDate | 2021 |
| publishDateSort | 2021 |
| record_format | eprints |
| spelling | RepoSLU167072022-01-26T00:15:58Z https://stud.epsilon.slu.se/16707/ Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya Lejon Flodin, Emelie Animal diseases Camels (Camelus dromedarius) are the most valuable livestock species in the arid and semi-arid lands in the Horn of Africa where the majority of the human population adopts a pastoralist lifestyle with extensive animal husbandry. Camels provide an important food source, milk, which is considered to be the most important commodity, and a source of income for the pastoralists. The health of the camel, and especially the udder health, is therefore very important for the pastoralist communities living in the arid areas in Kenya that do not support other livestock. Streptococcus agalactiae (SRA) is considered to be a zoonotic bacterium that can cause disease in both humans and animals but its zoonotic potential is not entirely clarified. It is a highly contagious udder-bound pathogen most known as a cause of mastitis, particularly in cattle, but also in camels. A few studies have also isolated SRA in apparently healthy camels, suggesting the bacteria could be a commensal. Antibiotic resistance (ABR) is a serious health threat to both humans and animals as well as a threat to food security, global development and economies worldwide. Antibiotic resistance in bacteria causing disease in camels can potentially be transmitted to people consuming camel products or handling these animals. The two antibiotic classes that are most frequently used in livestock production are tetracyclines and β-lactams. Tetracycline resistance has been observed in SRA isolates derived from camels in Kenya, but little resistance to β-lactams has been found. The prevalence of resistant and possibly multi-resistant bacteria in camels in Kenya is not known to a great extent. The aim of this study was to investigate if phenotypic ABR and possibly multiresistance is present in SRA isolates from dairy camels in Laikipia County, Kenya. The overall objective was to increase the knowledge of ABR among SRA in dairy camels in order to prevent further resistance development. In this study, six camel herds were selected for sampling; ranches (n=3), pastoralist (n=1) and smallholders (n=2). From each herd all lactating dams and their respective calves were sampled. In total, 179 individuals were sampled; 89 lactating camels and 90 calves. In lactating camels, milk samples were collected from lactating dams with a California Mastitis Test score of 2 or higher and swabs were taken from the nasal and vaginal mucosa; in their respective suckling calves from the nasal, oral and rectal mucosa. Primary identification of SRA in milk and swab samples was performed by bacterial culturing and confirmed by Matrix assisted laser desorption ionization-time of flight (MALDI-TOF). Antimicrobial susceptibility testing was performed by broth microdilution method to determine antimicrobial susceptibility in SRA isolates. In this study, SRA was isolated from 27% of the sampled individuals. The bacterium was found at all sampling sites, except for vaginal swabs, in both healthy and CMT-positive lactating dams as well as in apparently healthy calves, supporting the suggestion that SRA is a commensal and an opportunistic pathogen in camels. The overall prevalence of tetracycline-resistant SRA isolates was high (57%) in the six herds, especially in the pastoral and ranch managed systems. No resistance to penicillin was detected. Tetracycline-resistant SRA isolates were found at all SRA-positive sampling sites. All SRA isolates from milk samples were resistant to tetracycline. A few camels and calves were SRA-positive in more than one sampling site and resistance to tetracycline could be found in one, two or none of these isolates. The results in this study, in combination with earlier results from Kenya, shows that a shift from the use of tetracycline to penicillin when treating diseases in camels would be favourable as there is a risk that tetracycline would be ineffective. Bacteria that already have acquired resistance genes will however continue to spread within and between herds. Hence, finding a resistant bacterial isolate in a camel does not per se mean that the bacterium has become resistant due to antibiotic treatment. To avoid further development of resistant bacteria, prevention of disease is the most important objective. Healthy animals do not require antibiotic treatment. Kameler (Camelus dromedarius) är de mest värdefulla produktionsdjuren i öken- och torrområden i Afrikas horn. Övervägande delen av människorna som bor i dessa områden är pastoralister (herdefamiljer) och djuren hålls genom extensiv drift. Kamelerna bidrar både till pastoralisternas huvudsakliga livsmedelsförsörjning, där mjölken är den viktigaste produkten, men även som en inkomstkälla. Kamelernas hälsa, och då framför allt deras juverhälsa, är därför väldigt viktig för pastoralisterna som lever i dessa torrområden i Kenya vilka saknar förutsättningar för att hålla andra typer av produktionsdjur. Streptococcus agalactiae (SRA) anses vara en zoonotisk bakterie vilken kan orsaka sjukdom hos både människor och djur, men dess zoonotiska potential är inte helt utredd. Det är en mycket smittsam juverbunden patogen som främst förknippas med mastit, framförallt hos kor, men även hos kameler. Ett fåtal studier har även isolerat SRA från tillsynes friska kameler vilket kan tala för att bakterien skulle kunna vara en kommensal. Antibiotikaresistens (ABR) är ett allvarligt hot mot både människors och djurs hälsa, men även i aspekter som livsmedelsförsörjning, global utveckling och för ekonomier i hela världen. Antibiotikaresistens i bakterier som orsakar sjukdom hos kameler kan potentiellt överföras till människor som konsumerar produkter från kameler eller via närkontakt med kameler. De två antibiotikaklasser som används mest till produktionsdjur är tetracykliner och β-laktamer. Tetracyklinresistens har setts i SRA-isolat från kameler i Kenya, men förekomsten av resistens mot β-laktamer verkar vara låg. Förekomsten av resistenta och potentiellt multi-resistenta bakterier hos kameler i Kenya är ännu inte känd i någon större utsträckning. Syftet med studien var att undersöka om det förekommer fenotypisk ABR och eventuellt även multiresistens bland SRA-isolat från mjölkkameler i Laikipia County, Kenya. Det övergripande målet med studien var att bidra med mer kunskap om ABR bland SRA hos mjölkkameler för att förhindra ytterligare resistensutveckling. I studien ingick sex kamelbesättningar; rancher (n=3), pastoralist (n=1) och småbrukare (n=2). Från varje besättning provtogs alla lakterande djur och deras kalvar. Totalt provtogs 179 individer; 89 lakterande djur och 90 kalvar. Bland de lakterande kamelerna togs mjölkprov från kameler vilka fick värde 2 eller högre på California Mastitis Test och svabbprov togs från nos- och vaginalslemhinnan; från deras respektive kalvar togs svabbprover från nos-, oral-, och rektalslemhinnan. Primär identifiering av SRA i mjölk- och svabbprover gjordes genom bakterieodling; identifiering av bakterien bekräftades sedan med Matrix assisted laser desorption ionization-time of flight (MALDI-TOF). För att ta reda på den antimikrobiella känsligheten hos SRA-isolaten genomfördes antibiotikakänslighetsbestämning med hjälp av dilutionsmetoden. I denna studie isolerades SRA från 27 % av de provtagna kamelerna. Bakterien påvisades från samtliga provtagningsställen, förutom från vaginalslemhinnan, från både friska och CMT-positiva lakterande kameler samt tillsynes frisk kalvar, vilket kan tala för att SRA är en kommensal och en opportunistisk patogen hos kameler. Den totala förekomsten av tetracyklinresistenta SRA-isolat i de sex besättningarna var hög (57 %), framförallt i pastoralistbesättningen och rancherna. Ingen resistens mot penicillin påvisades. Tetracyklinresistenta SRA-isolat påvisades från samtliga provtagningsställen där bakterien påvisats. Samtliga SRA-isolat från mjölkprover var resistenta mot tetracyklin. Bland några kameler och kalvar kunde SRA isoleras från mer än ett provtagningsställe; resistens mot tetracyklin kunde sedan påvisas från det ena, båda eller ingetdera av provtagningsställena. Resultaten i denna studie, i kombination med tidigare resultat från Kenya, visar att det hade varit fördelaktigt att behandla sjukdom hos kameler med penicillin istället för tetracyklin då det finns en risk att tetracyklin inte fungerar effektivt. Bakterier som redan innehar förvärvade resistensgener kommer dock kunna spridas inom och mellan besättningar; isolering av ett resistent bakterieisolat hos en kamel måste därför inte betyda att bakterien utvecklat resistens på grund av antibiotikabehandling. För att undvika ytterligare utveckling av resistenta bakterier är det viktigaste målet att djuren håller sig friska. Om djuren är friska behöver de inte behandlas med antibiotika. 2021-05-21 Second cycle, A2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/16707/1/lejon_flodin_e_210202_.pdf Lejon Flodin, Emelie, 2021. Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya. Second cycle, A2E. Uppsala: (VH) > Dept. of Clinical Sciences (until 231231) <https://stud.epsilon.slu.se/view/divisions/OID-715.html> urn:nbn:se:slu:epsilon-s-16707 eng |
| spellingShingle | Animal diseases Lejon Flodin, Emelie Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya |
| title | Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya |
| title_full | Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya |
| title_fullStr | Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya |
| title_full_unstemmed | Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya |
| title_short | Antibiotic resistance in Streptococcus agalactiae isolates from dairy camels in Kenya |
| title_sort | antibiotic resistance in streptococcus agalactiae isolates from dairy camels in kenya |
| topic | Animal diseases |
| url | https://stud.epsilon.slu.se/16707/ https://stud.epsilon.slu.se/16707/ |