Flagellated bacteria
A crocheted amigurumi by Nunu Crochets
© 2023 Nunu Crochets
Flagellated bacteria
Information
Some of the rod-shaped bacteria (bacilli) move with flagella, and some others cannot move. Those
with flagella may come in twisted shapes. Here we have a bacillus (Escherichia coli, which lives in our
gut and is usually a good friend, producing vitamin K for us, but sometimes goes bad), a spiral bacillus
(Helicobacter pylori, which is the cause of stomach ulcers), and a coma-shaped bacillus (Vibrio
cholerae, which causes cholera). No matter whether they are good or bad, all these giant amigurumi
bacteria are cute, fast and so easy to make, and any microbiologist or biologist will love them!
What do you need?
- Yarn for the body and on a contrasting color for the eyes. For my sample, I used light green
(Escherichia coli), light pink (Helicobacter pylori), and dark red (Vibrio cholerae) fingering
cotton yarn (Mayflower Cotton 8/4 Solids colorway 1446, and Hobbii Rainbow Cotton 8/4 Solid
in colorways 61, and 86, respectively) and black mercerized cotton thread, size 5 (415 m per
100 g ball). I spent a total of 15 m of light green yarn, 13.5 m of light pink yarn, 10 m of dark
red yarn, and about 3 m of the black thread (0.5 m for each set of eyes) for the eyes.
- Two suitable hooks. I used a 2 mm hook for the bacteria and a 1.5 mm hook for the eyes.
- Stitch marker or a contrasting piece of yarn to mark the beginning of each round.
- Polyester fibrefill stuffing.
- Sewing needle.
- Optionally, you can use security eyes of an appropriate size.
What do you need to know before starting?
- The basic crochet stitches used in amigurumi (see the section below).
- To start crocheting in the round with a magic ring (you can substitute it by 2 chains and make
the stated number of stitches on the second chain from the hook).
- To crochet in the round in a continuous spiral.
- To work in the back bump of a chain and do invisible decreases (you can substitute them by
crocheting two single crochet stitches together or check the tutorial in the “Helping materials
and tutorials” section to learn how to do these techniques).
1 © 2023 Nunu Crochets
Flagellated bacteria
Gauge and measurements
Exact gauge is not important for this pattern, as long as you crochet thigh enough so there are no holes
between stitches, and the stuffing does not show.
Exact measurements will depend on the yarn and hooks used, and on your gauge. My samples are
around 3 cm tall.
Stitches and terminology
Here I use US terminology. Please, use the following table if you are used to UK terminology:
Abbreviation US UK
ch Chain Chain
sl st Slip stitch Slip stitch
sc Single crochet Double crochet
hdc Half double crochet Half treble crochet
inc Increase (2 sc in one stitch) Increase (2 sc in one stitch)
invdec Invisible decrease * Invisible decrease *
* You can substitute the invisible decreases by crocheting 2 sc together, or go to the “Helping materials
and tutorials” section to learn how to do invisible decreases.
Notes
- Do not join at the end of each round unless stated; the patterns are worked in continuous
spirals.
- All the pieces are started using a magic ring.
- All the stitches are worked through both loops, unless stated otherwise.
- You can use a stitch marker to mark the beginning of each round and move it for each row
(you can also weave in and out a piece of yarn in another color when you start a new round).
- Stitches in parentheses are to be repeated as many times as indicated after the parentheses
(for example, “(1 inc, 1 sc) x6” means that you have to crochet 1 inc and 1 sc six times).
- Numbers in square brackets indicate the total number of stitches in that round.
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Flagellated bacteria
Pattern for flagellated bacillus (Escherichia coli)
Body materials and tutorials” section if you need
help with working in the back bumps of the
Make a magic ring, 1 ch.
chains), and starting in the second chain from
R1: 6 sc in the magic ring. [6]
hook.
R2: 6 inc. [12]
You can use the tail from the body, or attach a
R3: (1 inc, 1 sc) x6. [18]
new yarn. Crochet 19 ch (you might want to use
R4: (1 inc, 2 sc) x6. [24]
a bigger hook). Working in the back bumps of
R5-16: 24 sc. [24]
the chains crochet a sl st in each of the 18 ch
R17: (1 invdec, 2 sc) x6. [18]
(starting in the second one).
If you prefer, you can sew now the eyes, or
leave them until the end. If you are using safety
Eyes (make two eyes)
eyes, place them now in rows 7 and 12.
Stuff through the hole. Make a magic ring, 1 ch.
R18: (1 invdec, 1 sc) x6. [12] R1: 6 sc in the magic ring. [6]
R19: 6 invdec. [6] Join with a sl st to the first stitch and fasten off.
Finish stuffing, close and fasten off, leaving a
long tail (around 0.5-0.7 m). Finishing
Place the eyes between rounds 5 and 7 and 11
Appendage (make one) and 13, and sew them using the long black tails;
All the sl st are worked in the back bumps of hide them inside the body.
the chains (see the tutorial at the “Helping
Pattern for flagellated spiral bacillus (Helicobacter pylori)
Body R8: 6 sc, 9 hdc, 3 sc. [18]
R9: 5 sc, 9 hdc, 4 sc. [18]
Make a magic ring, 1 ch.
R10: 4 sc, 9 hdc, 5 sc. [18]
R1: 6 sc in the magic ring. [6]
R11: 3 sc, 9 hdc, 6 sc. [18]
R2: 6 inc. [12]
R12: 2 sc, 9 hdc, 7 sc. [18]
R3: (1 inc, 1 sc) x6. [18]
R13: 1 sc, 9 hdc, 8 sc. [18]
R4: 18 sc. [18]
R14: 9 hdc, 9 sc. [18]
R5: 9 sc, 9 hdc. [18]
R15: 18 sc. [18]
R6: 8 sc, 9 hdc, 1 sc. [18]
R7: 7 sc, 9 hdc, 2 sc. [18]
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Flagellated bacteria
If you prefer, you can sew now the eyes, or a bigger hook). Working in the back bumps of
leave them until the end. If you are using safety the chains crochet a sl st in each of the 15 ch
eyes, place them now in rows 6 and 11. (starting in the second one). Attach a new yarn
Stuff through the hole. and repeat the process three more times.
R16: (1 invdec, 1 sc) x6. [12]
R17: 6 invdec. [6] Eyes (make two eyes)
Finish stuffing, close and fasten off, leaving a Make a magic ring, 1 ch.
long tail (around 0.5-0.7 m). R1: 6 sc in the magic ring. [6]
Join with a sl st to the first stitch and fasten off.
Appendages (make four)
All the sl st are worked in the back bumps of
Finishing
the chains (see the tutorial at the “Helping
Place the eyes between rounds 5 and 7 and 10
materials and tutorials” section if you need
and 12, and sew them using the long black tails;
help with working in the back bumps of the
hide them inside the body. Use a scrap of black
chains), and starting in the second chain from
yarn for the eyebrows.
hook.
You can use the tail from the body, or attach a
new yarn. Crochet 16 ch (you might want to use
Pattern for flagellated coma-shaped bacillus (Vibrio cholerae)
Body Stuff through the hole.
R16: (1 invdec, 1 sc) x6. [12]
Make a magic ring, 1 ch.
R17: 6 invdec. [6]
R1: 6 sc in the magic ring. [6]
Finish stuffing, close and fasten off, leaving a
R2: 6 inc. [12]
long tail (around 0.5-0.7 m).
R3: (1 inc, 1 sc) x6. [18]
R4-5: 18 sc. [18]
Appendage (make one)
R6-8: 9 sl st, 9 sc. [18]
All the sl st are worked in the back bumps of
R9-10: 9 sl st, 2 sc, 5 hdc, 2sc. [18]
the chains (see the tutorial at the “Helping
R11-13: 9 sl st, 9 sc. [18]
materials and tutorials” section if you need
R14-15: 18 sc. [18]
help with working in the back bumps of the
If you prefer, you can sew now the eyes, or
chains), and starting in the second chain from
leave them until the end. If you are using safety
hook.
eyes, place them now in rows 6 and 11.
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Flagellated bacteria
You can use the tail from the body, or attach a R1: 6 sc in the magic ring. [6]
new yarn. Crochet 15 ch (you might want to use Join with a sl st to the first stitch and fasten off.
a bigger hook). Working in the back bumps of
the chains crochet a sl st in each of the 14 ch Finishing
(starting in the second one). Place the eyes between rounds 5 and 7 and 10
and 12, and sew them using the long black tails;
Eyes (make two eyes)
hide them inside the body. Use a scrap of black
Make a magic ring, 1 ch. yarn for the eyebrows.
Where can you find more of my patterns?
Visit my Ravelry shop: https://www.ravelry.com/stores/nunu-crochets-designs
And you can follow me on Instagram: https://www.instagram.com/nunucrochets/ (@NunuCrochets)
5 © 2023 Nunu Crochets
Flagellated bacteria
Helping materials and tutorials
Here you can see all the bacteria to see how the eyes are placed.
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Flagellated bacteria
How to invisible decrease (right-handed version)
1. Identify the front loop of the first stitch (the front loop is highlighted in blue, and the back loop
is highlighted in red), and of the second stitch (the front loop is marked in purple) that you are
going to decrease.
2. Insert the hook only in the front loop of the first stitch to decrease and do not yarn over (you
will have 2 loops on your hook).
7 © 2023 Nunu Crochets
Flagellated bacteria
3. Insert the hook in the front loop of the second stitch to decrease (you will have 3 loops on your
hook); you will need to swing your hook to get it under the front loop.
4. Yarn over and draw through the first two loops, i.e. the two front loops (you will have 2 loops
on your hook).
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Flagellated bacteria
5. Yarn over and draw through the two loops to complete the invisible decrease.
9 © 2023 Nunu Crochets
Flagellated bacteria
How to invisible decrease (left-handed version)
1. Identify the front loop of the first stitch (the front loop is highlighted in blue, and the back loop
is highlighted in red), and of the second stitch (the front loop is marked in purple) that you are
going to decrease.
2. Insert the hook only in the front loop of the first stitch to decrease and do not yarn over (you
will have 2 loops on your hook).
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Flagellated bacteria
3. Insert the hook in the front loop of the second stitch to decrease (you will have 3 loops on your
hook); you will need to swing your hook to get it under the front loop.
4. Yarn over and draw through the first two loops, i.e. the two front loops (you will have 2 loops
on your hook).
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Flagellated bacteria
5. Yarn over and draw through the two loops to complete the invisible decrease.
12 © 2023 Nunu Crochets
Flagellated bacteria
How to crochet in the back bump of a chain (right-handed version)
1. Pass the yarn to the place you want to crochet the chain.
2. Insert the hook in the next space between stitches, and bring it to the front in the space where
the yarn is; yarn over and draw it to where you started.
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Flagellated bacteria
3. Chain as many chains as you need; from your point of view, each chain will look like a “v” (the
two loops from the second chain from hook are highlighted in red).
4. Turn the chain around to identify the back bump (the back bump of the second chain from
hook is highlighted in blue, and the two front loops of that same chain are in red); that is the
part in which you will be working.
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Flagellated bacteria
5. Insert the hook into the back bump of the second chain from the hook (blue) and make an sl
st.
6. Make a sl st in as many chains as you need; your work will look like this:
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Flagellated bacteria
How to crochet in the back bump of a chain (left-handed version)
1. Pass the yarn to the place you want to crochet the chain.
2. Insert the hook in the next space between stitches, and bring it to the front in the space where
the yarn is; yarn over and draw it to where you started.
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Flagellated bacteria
3. Chain as many chains as you need; from your point of view, each chain will look like a “v” (the
two loops from the second chain from hook are highlighted in red).
4. Turn the chain around to identify the back bump (the back bump of the second chain from
hook is highlighted in blue, and the two front loops of that same chain are in red); that is the
part in which you will be working.
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Flagellated bacteria
5. Insert the hook into the back bump of the second chain from the hook (blue) and make an sl
st.
6. Make a sl st in as many chains as you need; your work will look like this:
18 © 2023 Nunu Crochets
