Cocci, the spherical

bacteria
A crocheted amigurumi by Nunu Crochets

© 2021 Nunu Crochets

Cocci, the spherical bacteria

Information

Bacteria come in a bunch of shapes, although the main ones are spherical (cocci) and rod-shaped
(bacilli). Cocci can be found as single cells (as Lactococcus lactis, used to produce cheese) or they can
arrange themselves in pairs (called diplococci, as Neisseria gonorrhoeae, which causes gonorrhea),
chains (called streptococci, as Streptococcus pyogenes, which causes strep throat, among other
diseases), or groups of four (called tetrads, as Pediococcus acidilactici, a probiotic bacteria that lives in
our guts). These giant amigurumi cocci are cute, fast and 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 blue
(Lactococcus lactis), green (Neisseria gonorrhoeae), pink (Streptococcus pyogenes) and orange
(Pediococcus acidilactici) fingering cotton yarn (Mayflower Cotton 8/4 Solids colorway 1455,
and Hobbii Rainbow Cotton 8/4 Solid in colorways 23, 62 and 66, respectively) and black
mercerized cotton thread, size 5 (415 m per 100 g ball). I spent a total of 11.5 m of blue yarn,
26 m of green yarn, 38 m of pink yarn, 42 m of orange yarn and about 2 m of the black thread
(0.5 m for each set of eyes), and a small scrap of white thread for the sparkles in 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.
- Optionally, safety pins can be used to secure the two circles that are to be bound for the tetrad,
to make joining them easier.

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.

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Cocci, the spherical bacteria

- To 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 this technique) and to crochet two pieces together.

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
between 3 and 6 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
sc Single crochet Double crochet
sl st Slip stitch Slip stitch
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 pattern is 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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Pattern for single cell coccus (Lactococcus lactis)

Body R13: (1 invdec, 1 sc) x6. [12]

R14: 6 invdec. [6]
Make a magic ring, 1 ch.
Finish stuffing, close and fasten off.
R1: 6 sc in the magic ring. [6]
R2: 6 inc. [12]
Eyes (make two eyes)
R3: (1 inc, 1 sc) x6. [18]
R4: (1 inc, 2 sc) x6. [24] Make a magic ring, 1 ch.

R5: (1 inc, 3 sc) x6. [30] R1: 6 sc in the magic ring. [6]

R6-10: 30 sc. [30] Join with a sl st to the first stitch and fasten off.

R11: (1 invdec, 3 sc) x6. [24]

R12: (1 invdec, 2 sc) x6. [18] Finishing
If you prefer, you can sew now the eyes, or Place the eyes between rounds 6 and 7, and
leave them until the end. If you are using safety sew them using the long black tails; hide them
eyes, place them now between round 6 and 7 inside the body. With a scrap of white yarn,
and secure them. embroider the white sparkle in each eye.
Stuff through the hole.

Pattern for diplococci (Neisseria gonorrhoeae)

Body eyes, place one now between round 7 and 8

and secure it.
Make a magic ring, 1 ch.
Stuff through the hole.
R1: 6 sc in the magic ring. [6]
R13: 10 inc. [20]
R2: 6 inc. [12]
R14: (1 inc, 1 sc) x10. [30]
R3: (1 inc, 1 sc) x6. [18]
R15-19: 30 sc. [30]
R4: (1 inc, 2 sc) x6. [24]
R20: (1 invdec, 3 sc) x6. [24]
R5: (1 inc, 3 sc) x6. [30]
R21: (1 invdec, 2 sc) x6. [18]
R6-10: 30 sc. [30]
If you prefer, you can sew now one of the eyes,
R11: (1 invdec, 1 sc) x10. [20]
or leave it until the end. If you are using safety
R12: 10 invdec. [10]
eyes, place them now between round 17 and
If you prefer, you can sew now one of the eyes,
18 and secure it.
or leave it until the end. If you are using safety
Stuff through the hole.
R22: (1 invdec, 1 sc) x6. [12]

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Cocci, the spherical bacteria

R23: 6 invdec. [6] Working in the back bumps of the chains (see
Finish stuffing, close and fasten off. the tutorial at the “Helping materials and
tutorials” section if you need help with working
Eyes (make two eyes) in the back bumps of the chains), and starting

Make a magic ring, 1 ch. in the second chain from hook, crochet a sl st

R1: 6 sc in the magic ring. [6] in each chain (6 sl st).

Join with a sl st to the first stitch and fasten off.

Finishing

Pili or “hairs” (make as many as you like) Place the eyes between rounds 7 and 8 and

You can use the tail from the body, or attach a between rounds 18 and 19, and sew them

new yarn (you will need 5-6 m of yarn). Pass the using the long black tails; hide them inside the

yarn to the place where you want to crochet body. With a scrap of black yarn, embroider the

the “hair”, and make 7 ch (you might want to eyebrows.

use a bigger hook).

Pattern for streptococci (Streptococcus pyogenes)

Body eyes, place one now between round 16 and 17

and secure it.
Make a magic ring, 1 ch.
R21: 10 invdec. [10]
R1: 6 sc in the magic ring. [6]
Stuff through the hole.
R2: 6 inc. [12]
R22: 10 inc. [20]
R3: (1 inc, 1 sc) x6. [18]
R23: (1 inc, 1 sc) x10. [30]
R4: (1 inc, 2 sc) x6. [24]
R24-28: 30 sc. [30]
R5: (1 inc, 3 sc) x6. [30]
R29: (1 invdec, 1 sc) x10. [20]
R6-10: 30 sc. [30]
If you prefer, you can sew now one of the eyes,
R11: (1 invdec, 1 sc) x10. [20]
or leave it until the end. If you are using safety
R12: 10 invdec. [10]
eyes, place one now between round 26 and 27
Stuff through the hole.
and secure it.
R13: 10 inc. [20]
R30: 10 invdec. [10]
R14: (1 inc, 1 sc) x10. [30]
Stuff through the hole.
R15-19: 30 sc. [30]
R31: 10 inc. [20]
R20: (1 invdec, 1 sc) x10. [20]
R32: (1 inc, 1 sc) x10. [30]
If you prefer, you can sew now one of the eyes,
R33-37: 30 sc. [30]
or leave it until the end. If you are using safety

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Cocci, the spherical bacteria

R38: (1 invdec, 3 sc) x6. [24] R1: 6 sc in the magic ring. [6]
R39: (1 invdec, 2 sc) x6. [18] Join with a sl st to the first stitch and fasten off.
Stuff through the hole.
R40: (1 invdec, 1 sc) x6. [12] Finishing

R41: 6 invdec. [6] Place the eyes between rounds 16 and 17 and

Finish stuffing, close and fasten off. between rounds 26 and 27, and sew them
using the long black tails; hide them inside the
Eyes (make two eyes) body. With a scrap of black yarn, embroider the
eyebrows.
Make a magic ring, 1 ch.

Pattern for tetrad (Pediococcus acidilactici)

Body If you prefer, you can sew now the eyes, or

leave them until the end. If you are using safety
Make a magic ring, 1 ch.
eyes, place them now between round 7 and 8
R1: 6 sc in the magic ring. [6]
and secure them.
R2: 6 inc. [12]
Stuff both parts, placing balls of stuffing in each
R3: (1 inc, 1 sc) x6. [18]
coccus body (try not to place much stuffing in
R4: (1 inc, 2 sc) x6. [24]
the part between both cocci).
R5: (1 inc, 3 sc) x6. [30]
R13: (2 sc, 7 inc, 2 sc) x2. [36]
R6-7: 30 sc. [30]
R14: (2 sc, (1 sc, 1 inc) x7, 2 sc) x2. [50]
Fasten off.
R15-17: 50 sc. [50]
You need to do another piece following the
Stuff both parts, placing balls of stuffing in each
instructions above, but do not fasten off the
coccus body (try not to place much stuffing in
new piece.
the part between both cocci).
R8: Place the two pieces side by side (you can
R18: 5 ch, skip 25 stitches, join the last chain to
secure them together with safety pins) and join
stitch 26, 25 sc on the border of the body, 5 sc
them crocheting 5 sc through both pieces;
on the chains. [30]
then, crochet 50 sc around the bound pieces.
R19-21: 30 sc. [30]
[55]
R22: (1 invdec, 3 sc) x6. [24]
R9-10: 50 sc (do not crochet on the 5 sc binding
R23: (1 invdec, 2 sc) x6. [18]
both pieces). [50]
R24: (1 invdec, 1 sc) x6. [12]
R11: (2 sc, (1 sc, 1 invdec) x7, 2 sc) x2. [36]
R25: 6 invdec. [6]
R12: (2 sc, 7 invdec, 2 sc) x2. [22]
Finish stuffing, close and fasten off.

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Cocci, the spherical bacteria

R26: join a new yarn to the unfinished coccus, Join with a sl st to the first stitch and fasten off.
and crochet 25 sc on the border of the body
and 5 sc on the chains made in R18. [30] Finishing

R27-29: 30 sc. [30] Place the eyes between rounds 7 and , and sew

R30: (1 invdec, 3 sc) x6. [24] them using the long black tails; hide them

R31: (1 invdec, 2 sc) x6. [18] inside the body. With a scrap of white yarn,

R32: (1 invdec, 1 sc) x6. [12] embroider the white sparkle in each eye.

R33: 6 invdec. [6]

Although the pattern creates the shape of four
Finish stuffing, close and fasten off.
cocci bound together, you can highlight it by
stitching a small cross in the middle of all cocci
Eyes (make two eyes)
using the same yarn used for the body, that
Make a magic ring, 1 ch. crosses from the front to the back side and
R1: 6 sc in the magic ring. [6] tightens the area.

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)

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Cocci, the spherical bacteria

Helping materials and tutorials

Here you can see all the cocci to see how the eyes are placed, and also different views (front, side, and
back) of the final sample of the diplococci to see how I placed the pili or “hairs”.

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Cocci, the spherical 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).

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Cocci, the spherical 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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Cocci, the spherical bacteria

5. Yarn over and draw through the two loops to complete the invisible decrease.

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Cocci, the spherical 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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Cocci, the spherical 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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Cocci, the spherical bacteria

5. Yarn over and draw through the two loops to complete the invisible decrease.

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Cocci, the spherical 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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Cocci, the spherical 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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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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Cocci, the spherical 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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Cocci, the spherical 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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Cocci, the spherical 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:

19 © 2021 Nunu Crochets